Objectives: Cervical dysplasia which is the precursor or premalignant form of cervical cancer is prolonged; hence its diagnosis is essential for the early detection and inhibiting the development of cervical cancer. This review briefs the extensive studies conducted globally to gain knowledge about the development of cervical dysplasia along with the risk factors associated, role of human papilloma virus (HPV), potential diagnostic biomarkers and association with various micronutrient levels.
Materials and method: All these data were collected through extensive literature review.
Result: Based on the review, it can be stated that HPV virus (HPV 16 most commonly) is the most important etiological agent for the process of cervical carcinogenesis. However, HPV infection solely does not cause cervical cancer. There are various factors which act synergistically to develop cervical dysplasia and cancer. Smoking was found to be an important independent risk factor. There are studies which showed conflicting results regarding oral contraceptive intake association with cervical dysplasia. There are quite a few biomarkers like HPV DNA, p16INK4a, telomerase, and microRNA expression which have been identified as effective in diagnosing cervical dysplasia. Chromosome 3q mutation has been reported to be present in early dysplastic lesions; hence, it can be used in screening early lesions. Various micronutrient studies highlighted the facts that high plasma concentrations of several carotenoids and Vitamin C are inversely proportional to the degree of cervical dysplasia. Low red cell folate levels n plasma increases the risk of cervical dysplasia association. Low dietary intake of Vitamin A is also associated with increased risk of cervical dysplasia.
Conclusion: Finally, it can be stated that more extensive studies relating to nutritional and serum markers level need to be conducted with larger cohorts so that an appropriate nutrition plan can be implemented for these patients.
Cervical dysplasia is considered as a fence between benign and malignant lesions . Cervical cancer is the most common cancer of developing countries. Around 80 % of the global cervical cancer cases are reported from developing countries . The lesions which show characteristics of cervical dysplasia are known as squamous intraepithelial lesions (SIL) or cervical intraepithelial neoplasia (CIN).
Human papilloma virus (HPV) is considered as the most important etiology for development of cervical carcinogenesis; the initial idea of which was provided by Zur Hausen (1976) . Various studies have stated that this HPV infection is pretty common, especially in young women [4, 5]. So, getting infected with HPV virus does not necessarily mean that the women will develop cervical dysplasia. A persistent and prolonged HPV infection is the cornerstone of cervical dysplasia which was put forward by many studies [6-8]. Fife et al., (2001)  put forward the fact that infection by multiple HPV types could have a possible role in growth of cervical dysplasia. Another study  stated that HPV 16 and HPV 18 are the commonest high risk strains associated with cervical dysplasia.
According to yet another study, along with HPV 16 and 18, other strains like 31, 33, 35, 45, 52 and 58 constituted about 90% of cervical lesions .
There are several other risk factors which contribute to the development of cervical dysplasia and cancer with HPV infection. Among these risk factors; smoking, use of oral contraceptive pills (OCP) and nutritional deficiency of various ingredients are the most studied ones to the best of the author’s knowledge.
Many studies have indicated that the degree of cervical dysplasia is directly proportional to the intensity of smoking [12-14].
Correlation of OCP use with cervical dysplasia has been subjected to different views by various studies. Some authors reported that cervical dysplasia is associated with oral contraceptive use [15,16] whereas, some other authors concluded that the development of cervical dysplasia is independent of contraceptive use [17,18].
Many studies have correlated nutritional levels of various components with cervical dysplasia. Various studies were carried out to correlate folate and Vitamin C level with occurrence of cervical dysplasia [19-21]. Role of Vitamin A has also been widely studied by many authors. Butterworth Jr. et al., (1992) also evaluated the role of folic acid supplementation in the progression of cervical dysplasia .
Several biomarkers have also been studied through many years for early detection of cervical dysplasia and its development to cervical cancer. The markers which have been highlighted in this review are HPV DNA, p16INK4a, Ki-67, survivin, microRNA, mRNA, and telomerase.
There are studies which associated p16 expression in cervical dysplasia with HPV infection [23-26].
There are also studies which were conducted to correlate HPV DNA level expression in patients with cervical dysplasia [27-30].
Li et al., (2010), and Gocze et al., (2015) carried out studies to assess the correlation between microRNA expression in cervical tissues which show dysplasia or are HPV infected [31,32].
Authors have carried out studies to correlate mRNA expression profile in cervical dysplastic lesions [33,34]. Telomerase have also been considered as an essential biomarker in detecting dysplastic lesions. Riethdorf et al., (2001)  and Anderson et al., (2009)  evaluated the expression of telomerase in HPV positive cervical dysplastic lesions and evaluated the telomerase gene amplification in liquid based cytology samples of histologically conformed cervical dysplasia cases respectively.
Chromosome 3q genetic alteration; a common genetic alteration in cervical carcinomas have been evaluated in cervical dysplasia as well [37-40]. This review attempts to compile the findings of these studies and many more and provide an insight to the research update on cervical dysplasia (in the above mentioned scopes) till date and suggests what further research is necessary.
Pathogenesis and Association with HPV
The association of human papilloma virus (HPV) infection with cervical carcinogenesis was projected by Zur Hausen (1976) . A subgroup of the HPV types, known as the high risk papillomaviruses (HR-HPVs), mostly infect the mucosal epithelium of the genital tract; and they are considered the major cause of cervical cancer. HPV 16 and 18 are known to be highly associated with cervical cancer . HPV 16 is consistently the most common high risk HPV type, irrespective of study design and topographical area . Other common high-risk HPV types include: 31, 33, 35, 45, 52 and 58. These along with HPV 16 and 18 constitute for about 90% of cervical lesions .
Women infected with high risk-HPVs have a multifold risk of getting affected by a high grade cervical lesion paralleled with non-infected individuals. The nucleic acids of the high risk-HPVs can be readily identified in virtually all high grade cervical lesions ,. Therefore, detection and diagnosis of CIN is extremely necessary to prevent its further development to cervical cancer. Various epidemiological studies have discovered that high risk- HPV infections are very common and are easily detected, especially in young women [4, 5]. Mostly, the infection is self-limited and heals naturally without significant cervical pathologies. Only part of these infections continue to develop into cervical dysplastic lesions.
A study indicated that HPV DNA occurrence declines with age and increases with sexual activity and cigarette smoking . It is not related to the use of oral contraceptives, condoms or infection with sexually transmitted diseases.
Ho et al., (1995)  conducted a study to associate persistent HPV infection as a risk factor for persistent cervical dysplasia in patients with histologically diagnosed CIN II. It was concluded that type specific persistent HPV infection, particularly with a high viral load, may lead to a chronic cervical lesion which may further progress to cancer rather than spontaneous regression.
HPV testing is very helpful to screen patients with abnormal cervical smears diagnosed on cytology .
A study attempted to determine if infection with multiple subtypes of HPV was associated with higher risk of cervical dysplasia by using cervicovaginal lavage . This study supports a possible role for multiple HPV types (16, 51, 52, 56 and 58) in the development or progression of cervical dysplasia. The limitation of this study was the use of cervicovaginal lavage which made it impossible to isolate the HPV types detected in cervix and vagina.
Some other studies have assessed risk for development of intraepithelial lesions in the setting of persistent HPV infections [7, 8]. These studies indicated that multiple infections confer a four times increase in risk for persistent HPV infection and subsequent intraepithelial lesions.
Associated Risk Factors
While persistent HPV infection is the cornerstone of cervical dysplastic lesion formation and eventual development to cervical cancer, HPV infection alone does not cause cervical dysplasia. There are an array of risk factors which have been studied from time to time for assessing the risk associated with cervical dysplasia independently and in conjunction with HPV infection.
A prospective study was carried out to associate the correlation between steroid contraceptive use and rate of progression of cervical dysplasia . It was observed that there is a surge in severity of dysplasia and oral contraceptive pill users when compared with patients using other methods of contraception like barrier method.
Association of cigarette smoke with cervical dysplasia in a dose-response manner was studied by many researchers. These studies included the period of smoking as well as the number of cigarettes smoked [12-14], . La Vecchia et al ., (1986) reported higher risk estimates associated with longer periods of cigarette use , and Trevathan et al., (1983) showed a dose-response relationship for pack-years of cigarette use with increasing severity of cervical dysplasia .
Coker et al., (1992) found in their study that oral contraceptive use is not associated with cervical pre invasive lesion .
A case controlled study  was carried out to ascertain the risk factors for cases which was histologically confirmed as mild, moderate and severe dysplastic lesions. The incidence of cervical dysplasia was found to be greater in women who were smokers and those who took oral contraceptives rather than barrier methods.
Kjellberg et al., (2000)  concluded that after taking HPV infection in account, smoking proved to be the most significant risk factor for cervical dysplasia/neoplasia.
There are studies which stated that hormonal contraceptives are associated with a moderately increase in risk of cervical dysplasia, especially for HPV positive women suggesting that hormonal contraceptives act as a promoter in cervical carcinogenesis [47,48].
According to the WHO collaborative study, there is an elevated risk for oral contraceptives users that increased with duration of more than four years .
There is no increased risk in women who used hormonal contraceptives for less than 5 years; however, risk became obvious after 10 years .
In a case control study it was concluded that, hormonal contraceptive use is associated with some increase in the rate of cervical dysplasia which can be reduced by using barrier method during sex .
There are studies which indicated that there is a strong correlation between factors like multiparity, early age of marriage, early age of childbirth and lack of awareness/ education to cervical carcinogenesis [51-53].
Conflicting data are observed when OCP intake was considered as risk factor for cervical dysplasia development. Hence, further extensive studies are needed to determine the clear association between these.
Association of Cervical Dysplasia with Various Micronutrient Levels
Koss (1979)  pointed out that folic acid deficiency produces changes in cervical smear which are very similar to cervical dysplasia. Therefore, patients with such early lesions should undergo colposcopic evaluation; considering that the cervix should be normal in folic acid deficiency and abnormal in cervical dysplasia. To the best of the author’s knowledge, a detailed study supporting this theory is yet to be carried out.
Wassertheil-smoller et al ., (1981)  pointed out in a study that low Vitamin C intake is an independent contributor to risk of severe cervical dysplasia and it is important to explore a bit more about the protective role of supplementary Vitamin C for women at high risk of cervical cancer.
In another study, the red cell folate concentrations in OCP users with dysplasia was lower that the non OCP user controls. The dysplastic changes improved with folic acid therapy . However, whether the correction of dysplasia was due to the pharmacological response or nutritional effects of folic acid needs to be studied further. The protective effect of β carotene was established by
La Vecchia et al.,(1984) . Later on, Potischman et al. (1991)  supported it by serological indicators.
Wylie Rosett et al., (1985)  directed a case control study to define the dietary intake of Vitamin A in women having abnormal cervical cytology. This study demonstrated that women with less dietary intakes of total Vitamin A or β-carotene are more likely to have severe dysplasia than women with a higher intake of these food nutrients.
Butterworth et al., (1992)  conducted a study to associate any nutritional deficiency with cervical dysplasia. It was concluded from this study that low red blood cell folate levels (at or below 660 nmol/l) increase the effect of other risk factors for cervical dysplasia, in particular, that of HPV-16 infection. In this study, an increased tendency of dysplasia was found among HPV positive women with lowest folate level even though no treatment effect was observed in the study.
In another study by Butterworth Jr. et al., (1992)  it was concluded that although low folic acid levels increased the incidence of cervical dysplasia, oral folic acid supplementation did not alter the course of progression.
A theory was formulated that folate deficiency may act at the initiation stage [21,22] , while other vitamin deficiencies, such as Vitamin A, may act as promoters .
The laboratory and clinical studies in synergy provide a sturdy justification for testing retinoids in the regression of CIN of the cervix .
Goodman et al., (2000)  carried out a case control study to estimate the association of plasma levels of folate, Vitamin B12, homocysteine and cysteine in the various stages of cervical dysplasia. A very little or insignificant association of plasma levels of folate, homocysteine, or Vitamin B12 was found with the estimated risk of cervical dysplasia. However, a possible inverse relation of plasma cysteine levels with cervical dysplasia was brought forward, but a further study into this fact is required.
Biomarkers for Detecting Cervical Dysplasia
Several methods and markers were employed in the detection of cervical dysplasia over the years.
p16 and HPV DNA
Many studies indicated increased expression of p16INK4A, as a strong indicator of cervical neoplasia [23,24].
Klaes et al., (2001)  and Sano et al., (1998b)  found greater p16 expression on biopsy samples of high grade cervical dysplastic lesions.
A study was conducted to associate relationship between p16 expression by immunocytochemistry and HPV cytopathic effect in liquid based specimens . The findings of this study is suggestive of the fact that p16INK4A expression is a vital tool for HPV cytopathic detection in cervical samples, especially the ones which are admixed by a background of inflammation and organisms. MUC4, a mucin gene, has increased expression in cervical dysplasia; however, it has been found to be less sensitive. Thus this requires further research.
Viral DNA detection is associated with cancer cell lysis as well as with micro metastases shed from cancer cervix [27-29].
Hwang and Shroyer, (2012)  published a review article on the potent biomarkers of cervical dysplasia and carcinoma which can be useful for screening. They concluded that HPV DNA is the most extensively used biomarker. Randomized large studies have put forward the fact that when HPV testing is integrated in primary screening, an additional 50% to 70% premalignant cervical lesions is diagnosed [64,65].
Cocuzza et al., (2017)  directed an analysis to assess the quantitative and qualitative presence of circulating HPV DNA in patients with a recent history or cervical dysplasia and also to correlate between the plasma and the cervical level of HPV DNA taking into account seven high risk HPV types (16, 18, 31, 33, 45, 51 and 52) prevalent in that geographical area with the use of type-specific real-time quantitative PCR assays. In this study, contemporary detection of the seven high risk-HPV types inspected in cervical as well as plasma samples increased proportionately with the intensity of the lesion. This study reported that the quantification and detection of HPV DNA is possible in the plasma of women with a recent HPV infection as well as a low grade dysplasia of cervix.
However, longitudinal studies need to be carried out to further assess the role of detection of HPV DNA in the blood sample of patients whose infection is not yet symptomatic or in patients with early stage of cervical neoplasia.
p16INK4a and Ki-67
p16INK4a and Ki-67 are also considered useful markers for cervical dysplasia detection. Diffuse immunohistochemical positivity of p16INK4a has been seen in almost all cases of CIN II and CIN III. However, the drawback of p16INK4a is that it can sometimes also be expressed in normal endocervical lining cells, in cervical endometriosis, and tuboendometrial metaplasia . A specific pattern of CIN1+ lesions is intense p16INK4a expression in the lower third of the squamous mucosa.
p16INK4a immunohistochemistry may also aid in detecting CIN1 lesions which are accompanying HR-HPV types. The lesions which are positive possess an elevated risk for evolution to high-grade dysplasia or cancer . p16INK4a has also proven to be a sensitive as well as a specific diagnostic aid for underlying CIN2+ lesions in specimens collected for cervical cytology (68). Denton et al., (2010)  demonstrated that the use of p16INK4a in immunocytochemistry provides considerably higher specificity than HR HPV particularly for the ASC-US and LSIL cases diagnosed on cytology.
Ki67 expression by itself does not differentiate between HPV-induced dysplasia and benign reactive proliferating cells; therefore, the solo role of Ki67 to diagnose cervical dysplasia is limited. However, studies from Europe and United States, demonstrate that a dual staining approach for p16INK4a and Ki67 in cervical cytology sample can be used. This method provides a greater specificity than that of HR-HPV testing [70-72]. Adding p16INK4a immunostaining increased the diagnostic accuracy of high grade CIN significantly .
De-regulation of microRNAs, in connection with malignant transformation, is well known.
According to few studies, miRNAs are more effective than mRNA for differentiating between disease states .
Li et al., (2010)  established that the expression of miR-34a is considerably lower in HR HPV-infected tissues. This confirms that miR-34a acts as a tumour suppressive miRNA in HPV mediated cervical lesion transformation.
Gocze et al., (2015)  conducted a study to analyze the role of microRNA expression tissues of patients with known positive HPV status and histologically diagnosed cervical lesions. According to this study, in HPV positive cases, miR-27a showed upregulation and miR34a showed downregulation with increasing grades of cervical lesion.
Thus, assessment of miRNA expression can prove to be helpful for differentiating various cervical lesions and may help in the estimation of HPV infection outcome.
Tests for detecting E6/E7mRNA have been established; centred on the fact that E6/E7 manifestation results in an uncontrolled cell cycle proliferation due to degradation of tumour suppressor genes like p53 and Rb .
Molden et al., (2005)  conducted a comparative study of mRNA and HPV DNA by PCR on women with a preliminary cytology diagnosis of ASC-US or LSIL. It was concluded that although HPV mRNA is as sensitive as HPV DNA, it is more specific in detecting underlying high grade cervical dysplasia.
Telomerase has been put forward as an additional markers that can triage patients to avoid overtreatment and not to overlook dysplastic lesions.
Telomerase activity appears to increase proportionately with the increase in cervical cytology abnormality. Although Gorham et al., (1997)  and Wisman et al., (2000)  found telomerase activity in only a relatively small proportion of cases of high grade lesions, other studies have detected the telomerase activity bulk of them [77,78]. Telomerase can be utilised as a diagnostic supplement for the triage of patients with ASC-US or LSIL in Pap smears for consequent colposcopic examination and biopsy. The ultimate role for telomerase analysis may be to adjourn the treatment of patients who do not require further evaluation, instead of prevailing as a method to elevate the already high level of sensitivity of the Pap smear.
In a study by Riethdorf et al., (2001)  the strength of telomerase expression correlated with the intensity of HPV 16/18, as determined by in situ hybridization.
Andserson et al., (2009)  evaluated the human telomerase gene, TERC amplification in liquid based cytology (LBC) samples of histologically confirmed diagnoses of cervical lesions. TERC amplification study in cytological smears had the highest sensitivity and specificity among all markers used in this study (p16, MYC, HPV mRNA expression) to distinguish low grade cervical dysplasia from high grade dysplasia and cancer.
Two other studies applying the TERC FISH probe as a diagnostic marker on cervical Thin prep samples were published which were in agreement that TERC positivity can detect high-grade lesions with high sensitivity [79,80].
Studies have shown that acquisition of extra copies of chromosome 3q is a common genetic alteration in cervical carcinomas, and is less frequently associated with pre malignant lesions [37-39].
Heselmeyer - Haddad et al., (2003)  concluded that visualization of aneuploidy of chromosome 3q can detect dysplastic cells. They stated that the acquisition of additional copies of 3q may represent an early event in malignant transformation, which could provide a useful biomarker for screening of cervical dysplasia. The drawback of this study was that patient follow up and HPV status was not available.
In conclusion, cervical cancer is the fourth most common cancer among women globally . Although, substantial studies and sizable research had been conducted in the field of the above discussed topics of cervical dysplasia, there are few zones which have loopholes and further studies are required in those sectors.
There has been conflicting data regarding association of oral contraceptive use and development of cervical dysplasia. Studies with larger sample size should be implemented to shed some light into this conflict.
Cervical smear changes due to folic acid deficiency was found to be similar to the changes by cervical dysplasia. Further investigations regarding this and obtaining a clear cut differentiation needs to be carried out.
The fact that Vitamin C is an independent risk factor for cervical dysplasia needs to be further addressed and additional studies need to be carried out. Low serum folic acid level and low Vitamin A level were also found to be associated with increased cervical dysplasia; further studies are required to ascertain this finding and to outline a proper nutritional management plan for cervical dysplasia and attempt for preventing it. The inversely proportional relation of plasma cysteine level with cervical dysplasia, needs to be confirmed by further studies.
MUC4, a mucin gene, is found to have increased expression in cervical dysplasia; however, it has been found to be less sensitive. Thus this requires further research.
Longitudinal studies need to be carried out to further assess the role of detection of HPV DNA in blood of patients whose infection is asymptomatic and in patients with early stage of cervical dysplasia.
MiRNAs are considered to be a better choice for expression studies, since they are more precise for differentiating disease states than mRNA.
It was concluded in different studies , that although, HPV mRNA is as sensitive as HPV DNA but it is also more specific in detecting underlying high grade cervical dysplasia.
Telomerase activity appears to increase proportionately with the increase in cervical cytology abnormality in many studies. Most of these studies conducted used cervical samples. To the best of the author’s knowledge, there is meagre literature about the serum/plasma estimation of telomerase activity in detecting cervical intraepithelial lesions. Such studies if carried out in future and successful results produced, it will be an excellent mode of early diagnosis and that too from patient’s blood sample. In the future, one can think of a screening strategy in which HPV-positive Pap smears are triaged with the help of the TERC marker that would contribute to a more evidence- based clinical management and patient categorization.
It is expected that the points highlighted in this review, will be helpful for the future investigators for carrying out further research in this field.
- Capalash N, Sobti RC. Epidemiology of cervical cancer ‑ A case control study on North Indian population. Indian J Cancer. 1999; 36:179-185.
- Kishore J. Reproductive and child health program –II. In: Kishore J (Editor), National health programs of India, 9th Edition. Century Publishers, New Delhi. 2011;155-160.
- Zur Hausen H. Condylomata acuminata and human genital cancer. Cancer Res. 1976; 36:794.
- Koutsky L.. Epidemiology of genital human papillomavirus infection. The American Journal of Medicine. 1997; 102(5A)DOI
- Ho G. Y., Bierman R., Beardsley L., Chang C. J., Burk R. D.. Natural history of cervicovaginal papillomavirus infection in young women. The New England Journal of Medicine. 1998; 338(7)DOI
- Ho G. Y., Burk R. D., Klein S., Kadish A. S., Chang C. J., Palan P., Basu J., Tachezy R., Lewis R., Romney S.. Persistent genital human papillomavirus infection as a risk factor for persistent cervical dysplasia. Journal of the National Cancer Institute. 1995; 87(18)DOI
- Kjaer SK, Brule AJC, Paull G, Svare EI, Sherman ME, Thomsen BL, Suntum M, Bock JE, Poll PA, Meijer CJLM. Type specific persistence of high risk human papillomavirus (HPV) as indicator of high grade cervical squamous intraepithelial lesions in young women: population based prospective follow up study. BMJ (Clinical research ed.). 2002; 325(7364)DOI
- Dalstein V, Riethmuller D, Prétet JL, Le Bail Carval K, Sautière JL, Carbillet JP, Kantelip B, Schaal JP, Mougin C. Persistence and load of high-risk HPV are predictors for development of high-grade cervical lesions: a longitudinal French cohort study. International Journal of Cancer. 2003; 106(3)DOI
- Fife K. H., Cramer H. M., Schroeder J. M., Brown D. R.. Detection of multiple human papillomavirus types in the lower genital tract correlates with cervical dysplasia. Journal of Medical Virology. 2001; 64(4)DOI
- Muñoz N.. Human papillomavirus and cancer: the epidemiological evidence. Journal of Clinical Virology: The Official Publication of the Pan American Society for Clinical Virology. 2000; 19(1-2)DOI
- de Sanjose S, Quint WG, Alemany L, et al. Retrospective International Survey and HPV Time Trends Study Group: Human papilloma virus genotype attribution in invasive cervical cancer: a retrospective cross-sectional worldwide study. Lancet Oncol. 2011; 11:1048-1056.
- Trevathan E., Layde P., Webster L. A., Adams J. B., Benigno B. B., Ory H.. Cigarette smoking and dysplasia and carcinoma in situ of the cervix. JAMA. 1983; 250(4)
- La Vecchia C., Franceschi S., Decarli A., Fasoli M., Gentile A., Tognoni G.. Cigarette smoking and the risk of cervical neoplasia. American Journal of Epidemiology. 1986; 123(1)DOI
- Cuzick J., Singer A., De Stavola B. L., Chomet J.. Case-control study of risk factors for cervical intraepithelial neoplasia in young women. European Journal of Cancer (Oxford, England: 1990). 1990; 26(6)DOI
- Stern E., Forsythe A. B., Youkeles L., Coffelt C. F.. Steroid contraceptive use and cervical dysplasia: increased risk of progression. Science (New York, N.Y.). 1977; 196(4297)DOI
- McFarlane-Anderson N, Bazuaye PE, Jackson MD, Smikle M, Fletcher HM. Cervical dysplasia and cancer and the use of hormonal contraceptives in Jamaican women. BMC women's health. 2008; 8DOI
- Coker A. L., McCann M. F., Hulka B. S., Walton L. A.. Oral contraceptive use and cervical intraepithelial neoplasia. Journal of Clinical Epidemiology. 1992; 45(10)DOI
- Trimble CL, Piantadosi S, Gravitt P, Ronnett B, Pizer E, Elko A, Wilgus B, Yutzy W, Daniel R, Shah K, Peng S, Hung C, Roden R, Wu TC, Pardoll D. Spontaneous regression of high-grade cervical dysplasia: effects of human papillomavirus type and HLA phenotype. Clinical Cancer Research: An Official Journal of the American Association for Cancer Research. 2005; 11(13)DOI
- Koss LG. Diagnostic cytology and its histopathologic bases (Vol. 1). Lippincott Williams and Wilkins. 1979.
- Wassertheil-Smoller S., Romney S. L., Wylie-Rosett J., Slagle S., Miller G., Lucido D., Duttagupta C., Palan P. R.. Dietary vitamin C and uterine cervical dysplasia. American Journal of Epidemiology. 1981; 114(5)DOI
- Butterworth C. E.. Effect of folate on cervical cancer. Synergism among risk factors. Annals of the New York Academy of Sciences. 1992; 669DOI
- Butterworth C. E., Hatch K. D., Soong S. J., Cole P., Tamura T., Sauberlich H. E., Borst M., Macaluso M., Baker V.. Oral folic acid supplementation for cervical dysplasia: a clinical intervention trial. American Journal of Obstetrics and Gynecology. 1992; 166(3)DOI
- Sano T., Oyama T., Kashiwabara K., Fukuda T., Nakajima T.. Expression status of p16 protein is associated with human papillomavirus oncogenic potential in cervical and genital lesions. The American Journal of Pathology. 1998; 153(6)DOI
- Keating J. T., Cviko A., Riethdorf S., Riethdorf L., Quade B. J., Sun D., Duensing S., Sheets E. E., Munger K., Crum C. P.. Ki-67, cyclin E, and p16INK4 are complimentary surrogate biomarkers for human papilloma virus-related cervical neoplasia. The American Journal of Surgical Pathology. 2001; 25(7)DOI
- Klaes R., Friedrich T., Spitkovsky D., Ridder R., Rudy W., Petry U., Dallenbach-Hellweg G., Schmidt D., Knebel Doeberitz M.. Overexpression of p16(INK4A) as a specific marker for dysplastic and neoplastic epithelial cells of the cervix uteri. International Journal of Cancer. 2001; 92(2)DOI
- Saqi A, Pasha TL, McGrath CM, Yu GH, Zhang P, Gupta P. Overexpression of p16INK4A in liquid-based specimens (SurePath) as marker of cervical dysplasia and neoplasia. Diagnostic Cytopathology. 2002; 27(6)DOI
- Sathish N, Abraham P, Peedicayil A, Sridharan G, John S, Shaji RV, Chandy G. HPV DNA in plasma of patients with cervical carcinoma. Journal of Clinical Virology: The Official Publication of the Pan American Society for Clinical Virology. 2004; 31(3)DOI
- Ho C, Yang S, Chien T, Huang S, Jeng C, Chang S. Detection and quantitation of human papillomavirus type 16, 18 and 52 DNA in the peripheral blood of cervical cancer patients. Gynecologic Oncology. 2005; 99(3)DOI
- Gnanamony M, Peedicayil A, Subhashini J, Ram TS, Rajasekar A, Gravitt P, Abraham P. Detection and quantitation of HPV 16 and 18 in plasma of Indian women with cervical cancer. Gynecologic Oncology. 2010; 116(3)DOI
- Cocuzza CE, Martinelli M, Sina F, Piana A, Sotgiu G, Dell’Anna T, Musumeci R. Human papillomavirus DNA detection in plasma and cervical samples of women with a recent history of low grade or precancerous cervical dysplasia. PLoS ONE. 2017; 12(11)DOI
- Li B, Hu Y, Ye F, Li Y, Lv W, Xie X. Reduced miR-34a expression in normal cervical tissues and cervical lesions with high-risk human papillomavirus infection. International Journal of Gynecological Cancer: Official Journal of the International Gynecological Cancer Society. 2010; 20(4)DOI
- Gocze K, Gombos K, Kovacs K, Juhasz K, Gocze P, Kiss I. MicroRNA expressions in HPV-induced cervical dysplasia and cancer. Anticancer Research. 2015; 35(1)
- Hudson J. B., Bedell M. A., McCance D. J., Laiminis L. A.. Immortalization and altered differentiation of human keratinocytes in vitro by the E6 and E7 open reading frames of human papillomavirus type 18. Journal of Virology. 1990; 64(2)DOI
- Molden T, Nygård JF, Kraus I, Karlsen F, Nygård M, Skare GB, Skomedal H, Thoresen SO, Hagmar B. Predicting CIN2+ when detecting HPV mRNA and DNA by PreTect HPV-proofer and consensus PCR: A 2-year follow-up of women with ASCUS or LSIL Pap smear. International Journal of Cancer. 2005; 114(6)DOI
- Riethdorf S., Riethdorf L., Schulz G., Ikenberg H., Jänicke F., Löning T., Park T. W.. Relationship between telomerase activation and HPV 16/18 oncogene expression in squamous intraepithelial lesions and squamous cell carcinomas of the uterine cervix. International Journal of Gynecological Pathology: Official Journal of the International Society of Gynecological Pathologists. 2001; 20(2)DOI
- Andersson S, Sowjanya P, Wangsa D, Hjerpe A, Johansson B, Auer G, Gravitt PE, Larsson C, Wallin K, Ried T, Heselmeyer-Haddad K. Detection of genomic amplification of the human telomerase gene TERC, a potential marker for triage of women with HPV-positive, abnormal Pap smears. The American Journal of Pathology. 2009; 175(5)DOI
- Heselmeyer K., Schröck E., Manoir S., Blegen H., Shah K., Steinbeck R., Auer G., Ried T.. Gain of chromosome 3q defines the transition from severe dysplasia to invasive carcinoma of the uterine cervix. Proceedings of the National Academy of Sciences of the United States of America. 1996; 93(1)DOI
- Matthews C. P., Shera K. A., McDougall J. K.. Genomic changes and HPV type in cervical carcinoma. Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine (New York, N.Y.). 2000; 223(3)DOI
- Dellas A., Torhorst J., Jiang F., Proffitt J., Schultheiss E., Holzgreve W., Sauter G., Mihatsch M. J., Moch H.. Prognostic value of genomic alterations in invasive cervical squamous cell carcinoma of clinical stage IB detected by comparative genomic hybridization. Cancer Research. 1999; 59(14)
- Heselmeyer-Haddad K, Janz V, Castle PE, Chaudhri N, White N, Wilber K, Morrison LE, Auer G, Burroughs FH, Sherman ME, Ried T. Detection of genomic amplification of the human telomerase gene (TERC) in cytologic specimens as a genetic test for the diagnosis of cervical dysplasia. The American Journal of Pathology. 2003; 163(4)DOI
- Trottier H, Mahmud S, Costa MC, Sobrinho JP, Duarte-Franco E, Rohan TE, Ferenczy A, Villa LL, Franco EL. Human papillomavirus infections with multiple types and risk of cervical neoplasia. Cancer Epidemiology, Biomarkers & Prevention: A Publication of the American Association for Cancer Research, Cosponsored by the American Society of Preventive Oncology. 2006; 15(7)DOI
- Walboomers J. M., Meijer C. J.. Do HPV-negative cervical carcinomas exist?. The Journal of Pathology. 1997; 181(3)DOI
- Davidson M., Schnitzer P. G., Bulkow L. R., Parkinson A. J., Schloss M. L., Fitzgerald M. A., Knight J. A., Murphy C. M., Kiviat N. B., Toomey K. E.. The prevalence of cervical infection with human papillomaviruses and cervical dysplasia in Alaska Native women. The Journal of Infectious Diseases. 1994; 169(4)DOI
- Solomon D., Schiffman M., Tarone R.. Comparison of three management strategies for patients with atypical squamous cells of undetermined significance: baseline results from a randomized trial. Journal of the National Cancer Institute. 2001; 93(4)DOI
- Vet H. C., Sturmans F.. Risk factors for cervical dysplasia: implications for prevention. Public Health. 1994; 108(4)DOI
- Kjellberg L., Hallmans G., Ahren A. M., Johansson R., Bergman F., Wadell G., Angström T., Dillner J.. Smoking, diet, pregnancy and oral contraceptive use as risk factors for cervical intra-epithelial neoplasia in relation to human papillomavirus infection. British Journal of Cancer. 2000; 82(7)DOI
- Delgado-Rodriguez M., Sillero-Arenas M., Martin-Moreno J. M., Galvez-Vargas R.. Oral contraceptives and cancer of the cervix uteri. A meta-analysis. Acta Obstetricia Et Gynecologica Scandinavica. 1992; 71(5)DOI
- Ursin G., Peters R. K., Henderson B. E., Ablaing G., Monroe K. R., Pike M. C.. Oral contraceptive use and adenocarcinoma of cervix. Lancet (London, England). 1994; 344(8934)DOI
- Thomas D. B., Ray R. M.. Oral contraceptives and invasive adenocarcinomas and adenosquamous carcinomas of the uterine cervix. The World Health Organization Collaborative Study of Neoplasia and Steroid Contraceptives. American Journal of Epidemiology. 1996; 144(3)DOI
- Moreno V, Bosch FX, Muñoz N, Meijer CJLM, Shah KV, Walboomers JMM, Herrero R, Franceschi S. Effect of oral contraceptives on risk of cervical cancer in women with human papillomavirus infection: the IARC multicentric case-control study. Lancet (London, England). 2002; 359(9312)DOI
- Saraiya UB, Lulla M, Gupta PC, Shirsat L, Garud M. Socioeconomic profile of women with cancer cervix, dysplasia and control group. J Obstet Gynecol India. 1983; 33:374-377.
- Dutta P. K., Upadhyay A., Dutta M., Urmil A. C., Thergaonkar M. P., Ganguly S. S.. A case control study of cancer cervix patients attending Command Hospital, Pune. Indian Journal of Cancer. 1990; 27(2)
- Dhurwey DB, Gaur DT. Study of cervical dysplasia in relation to socioeconomic status and various environmental high risk factors. International Journal of Clinical Obstetrics and Gynaecology. 2020; 4(6)DOI
- Butterworth C. E., Hatch K. D., Gore H., Mueller H., Krumdieck C. L.. Improvement in cervical dysplasia associated with folic acid therapy in users of oral contraceptives. The American Journal of Clinical Nutrition. 1982; 35(1)DOI
- La Vecchia C., Franceschi S., Decarli A., Gentile A., Fasoli M., Pampallona S., Tognoni G.. Dietary vitamin A and the risk of invasive cervical cancer. International Journal of Cancer. 1984; 34(3)DOI
- Potischman N., Herrero R., Brinton L. A., Reeves W. C., Stacewicz-Sapuntzakis M., Jones C. J., Brenes M. M., Tenorio F., Britton R. C., Gaitan E.. A case-control study of nutrient status and invasive cervical cancer. II. Serologic indicators. American Journal of Epidemiology. 1991; 134(11)DOI
- Wylie-Rosett J. A., Romney S. L., Slagle N. S., Wassertheil-Smoller S., Miller G. L., Palan P. R., Lucido D. J., Duttagupta C.. Influence of vitamin A on cervical dysplasia and carcinoma in situ. Nutrition and Cancer. 1984; 6(1)DOI
- Butterworth C. E., Hatch K. D., Macaluso M., Cole P., Sauberlich H. E., Soong S. J., Borst M., Baker V. V.. Folate deficiency and cervical dysplasia. JAMA. 1992; 267(4)
- Correa P.. Vitamins and cancer prevention. Cancer Epidemiology, Biomarkers & Prevention: A Publication of the American Association for Cancer Research, Cosponsored by the American Society of Preventive Oncology. 1992; 1(3)
- Sporn M. B., Roberts A. B.. Cervical dysplasia regression induced by all-trans-retinoic acid. Journal of the National Cancer Institute. 1994; 86(7)DOI
- Goodman M. T., McDuffie K., Hernandez B., Wilkens L. R., Selhub J.. Case-control study of plasma folate, homocysteine, vitamin B(12), and cysteine as markers of cervical dysplasia. Cancer. 2000; 89(2)DOI
- Sano T., Oyama T., Kashiwabara K., Fukuda T., Nakajima T.. Immunohistochemical overexpression of p16 protein associated with intact retinoblastoma protein expression in cervical cancer and cervical intraepithelial neoplasia. Pathology International. 1998; 48(8)DOI
- Hwang SJ, Shroyer KR. Biomarkers of cervical dysplasia and carcinoma. Journal of Oncology. 2012; 2012DOI
- Bulkmans NWJ, Rozendaal L L, Snijders PJF, Voorhorst FJ, Boeke AJP, Zandwijken RJ, Kemenade FJ, Verheijen HM, Groningen K, Boon ME, Keuning JF, Ballegooijen M, Brule AJC, Meijer JLM. POBASCAM, a population-based randomized controlled trial for implementation of high-risk HPV testing in cervical screening: design, methods and baseline data of 44,102 women. International Journal of Cancer. 2004; 110(1)DOI
- Naucler P, Ryd W, Törnberg S, Strand A, Wadell G, Elfgren K, Rådberg T, Strander B, Johansson B, Forslund O, Hansson B, Rylander E, Dillner J. Human papillomavirus and Papanicolaou tests to screen for cervical cancer. The New England Journal of Medicine. 2007; 357(16)DOI
- Tringler B, Gup CJ, Singh M, Groshong S, Shroyer AL, Heinz DE, Shroyer KR. Evaluation of p16INK4a and pRb expression in cervical squamous and glandular neoplasia. Human Pathology. 2004; 35(6)DOI
- Murphy N., Ring M., Killalea A. G., Uhlmann V., O'Donovan M., Mulcahy F., Turner M., McGuinness E., Griffin M., Martin C., Sheils O., O'Leary J. J.. p16INK4A as a marker for cervical dyskaryosis: CIN and cGIN in cervical biopsies and ThinPrep smears. Journal of Clinical Pathology. 2003; 56(1)DOI
- Samarawardana P, Dehn DL, Singh M, Franquemont D, Thompson C, Gaido L, Torkko KC, Homer P, Burke S, Titmus MA, Nayi V, Shroyer KR. p16(INK4a) is superior to high-risk human papillomavirus testing in cervical cytology for the prediction of underlying high-grade dysplasia. Cancer Cytopathology. 2010; 118(3)DOI
- Denton Karin J., Bergeron Christine, Klement Petra, Trunk Marcus J., Keller Thomas, Ridder Ruediger. The sensitivity and specificity of p16(INK4a) cytology vs HPV testing for detecting high-grade cervical disease in the triage of ASC-US and LSIL pap cytology results. American Journal of Clinical Pathology. 2010; 134(1)DOI
- Liu H, Shi J, Wilkerson M, Huang Y, Meschter S, Dupree W, Lin F. Immunohistochemical detection of p16INK4a in liquid-based cytology specimens on cell block sections. Cancer. 2007; 111(2)DOI
- Meyer JL, Hanlon DW, Andersen BT, Rasmussen OF, Bisgaard K. Evaluation of p16INK4a expression in ThinPrep cervical specimens with the CINtec p16INK4a assay: correlation with biopsy follow-up results. Cancer. 2007; 111(2)DOI
- Schmidt D, Bergeron C, Denton KJ, Ridder R. p16/ki-67 dual-stain cytology in the triage of ASCUS and LSIL papanicolaou cytology: results from the European equivocal or mildly abnormal Papanicolaou cytology study. Cancer Cytopathology. 2011; 119(3)DOI
- Bergeron C, Ordi J, Schmidt D, Trunk MJ, Keller T, Ridder R. Conjunctive p16INK4a testing significantly increases accuracy in diagnosing high-grade cervical intraepithelial neoplasia. American Journal of Clinical Pathology. 2010; 133(3)DOI
- Lu J, Getz G, Miska EA, Alvarez-Saavedra E, Lamb J, Peck D, Sweet-Cordero A, Ebert BL, Mak RH, Ferrando AA, Downing JR, Jacks T, Horvitz HR, Golub TR. MicroRNA expression profiles classify human cancers. Nature. 2005; 435(7043)DOI
- Gorham H, Yoshida K, Sugino T, Marsh G, Manek S, Charnock M, Tarin D, Goodison S. Telomerase activity in human gynaecological malignancies.. Journal of Clinical Pathology. 1997; 50(6)
- Wisman G. B., De Jong S., Meersma G. J., Helder M. N., Hollema H., Vries E. G., Keith W. N., Zee A. G.. Telomerase in (pre)neoplastic cervical disease. Human Pathology. 2000; 31(10)DOI
- Kawai K., Yaginuma Y., Tsuruoka H., Griffin M., Hayashi H., Ishikawa M.. Telomerase activity and human papillomavirus (HPV) infection in human uterine cervical cancers and cervical smears. European Journal of Cancer (Oxford, England: 1990). 1998; 34(13)DOI
- Reddy V. G., Khanna N., Jain S. K., Das B. C., Singh N.. Telomerase-A molecular marker for cervical cancer screening. International Journal of Gynecological Cancer: Official Journal of the International Gynecological Cancer Society. 2001; 11(2)DOI
- Sokolova I, Algeciras-Schimnich A, Song M, Sitailo S, Policht F, Kipp BR, Voss JS, Halling KC, Ruth A, King W, Underwood D, Brainard J, Morrison L. Chromosomal biomarkers for detection of human papillomavirus associated genomic instability in epithelial cells of cervical cytology specimens. The Journal of molecular diagnostics: JMD. 2007; 9(5)DOI
- Caraway NP, Khanna A, Dawlett M, Guo M, Guo N, Lin E., Katz RL. Gain of the 3q26 region in cervicovaginal liquid-based pap preparations is associated with squamous intraepithelial lesions and squamous cell carcinoma. Gynecologic Oncology. 2008; 110(1)DOI
- Sung H, Ferlay J, Siegel RL, Laversanne M, Soerjomataram I, Jemal A, Bray F. Global Cancer Statistics 2020: GLOBOCAN Estimates of Incidence and Mortality Worldwide for 36 Cancers in 185 Countries. CA: a cancer journal for clinicians. 2021; 71(3)DOI