Smoking-Driven Inflammasome-Associated Inflammation in Colorectal Cancer: A Two-Phase Discovery and Validation Study of Serum Biomarkers

Aysar Mahmood Mohammed Atea; Jinan Hameed Abushana; AbdulQader M. AbdulQader; Amenh Mohammed Abdulrahman

doi:10.31557/APJCB.2026.11.4.1069

Authors

Aysar Mahmood Mohammed Atea Department of Anatomy , College of Medicine, University of Fallujah, Iraq. https://orcid.org/0000-0003-4992-7686
Jinan Hameed Abushana Department of Chemistry and Biochemistry , Collage of medicine, Aliraqia University, Iraq. https://orcid.org/0000-0001-6581-2489
AbdulQader M. AbdulQader College of Dentistry, Al-Iraqia University, Baghdad, Iraq. https://orcid.org/0000-0002-5672-8717
Amenh Mohammed Abdulrahman Department of Pharmacology, College of medicine, Al-Iraqia University, Iraq.

DOI:

https://doi.org/10.31557/APJCB.2026.11.4.1069

Keywords:

Inflammasome and Smoking, Colorectal cancer and Composite diagnostic indices, IL-8 and CRP / galectin-1 axis, Mediation analysis

Abstract

Introduction: To identify and validate serum biomarkers of smoking-related inflammasome activation in CRC and quantify the mediating role of inflammatory markers in the smoking–CRC association.

Materials and Methods: This two-phase retrospective study was conducted at the Oncology Teaching Hospital, Baghdad Medical City, Iraq, from April 2024 to April 2025. A total of 200 participants were enrolled and evenly divided into four groups (n 50 each): non-smoker controls, smoker controls, non-smoker colorectal cancer (CRC) patients, and smoker CRC patients. nine serum biomarkers were measured using ELISA assays, including interleukin-8 (IL-8), interleukin-37 (IL-37), C-reactive protein (CRP), adiponectin, forkhead box P3 (FoxP3), sestrin-1, galectin-1, P selectin, and carcinoembryonic antigen (CEA). Three composite indices (Provisional Smoking-Driven Inflammasome Score - pSIS, Provisional Smoking-Attributable Risk Index - pSMRI, and Provisional Pyroptosis Activity Score - pPAS) were calculated. Statistical analyses involved mediation analysis, LASSO regression, and random forest with Boruta feature selection.

Results: Outcomes revealed that smokers with CRC exhibited a distinct pro-inflammatory signature, characterized by significantly elevated IL-8, CRP, and galectin-1, alongside reduced IL-37 and adiponectin. Mediation analysis showed that these three markers collectively mediated 73.8% (95% CI: 52.1%–89.3%) of the smoking–CRC relationship. The three composite indices (pSIS, pSMRI, and pPAS) showed progressively increasing median values from healthy controls to smoker CRC patients (p < 0.001). All three indices demonstrated excellent discriminatory ability, with area under the curve (AUC) values of 0.92 (pSIS), 0.91 (pPAS), and 0.90 (pSMRI), significantly outperforming CEA (AUC: 0.85; DeLong test, p < 0.05). LASSO and Boruta algorithms confirmed IL-8, CRP, and galectin-1 as the most critical features.

Conclusion: This study demonstrates that inflammatory markers (IL-8, CRP, and galectin-1) statistically mediate 73.8% of the smoking-CRC association, providing strong evidence consistent with, but not proof of, an inflammasome-mediated causal pathway. This study offers a blood test that detects harmful inflammation early, enabling earlier diagnosis and potential targets for prevention. Prospective validation is required to confirm causality.