The impact of smoking on survival and extranodal extension in colorectal cancer patients: a retrospective cohort study

Year 2026, Volume: 8 Issue: 2, 204 - 209, 10.03.2026

Mesud Fakirullahoğlu , Mehmet Torun

https://doi.org/10.38053/acmj.1851804

https://izlik.org/JA33AW56TN

Abstract

Aims: This study aimed to evaluate the impact of smoking on clinical outcomes, including tumor localization, staging, extranodal extension, and overall survival in patients diagnosed with colorectal cancer (CRC).
Methods: In this retrospective cohort study, 401 patients with histologically confirmed CRC treated at Erzurum Faculty of Medicine between 2019 and 2023 were analyzed. Based on documented history, patients were classified as smokers or non-smokers. Variables included age, gender, tumor localization, tumor staging (T and N), and presence of extranodal extension (EX). Kaplan-Meier survival analysis and Log-Rank test were used to compare cumulative survival. Chi-square test and Mann-Whitney U test were applied for categorical and continuous variables, respectively.
Results: The mean age was 67.4±11.2 years, with smokers being significantly older than non-smokers (69.5±9.6 vs. 66.1±11.8, p=0.005). Tumor localization did not differ significantly between groups. EX was more common among smokers (33.8%) compared to non-smokers (19.4%, p=0.001). Cumulative survival was significantly shorter in smokers (90.2 months; 95% CI: 82.5-97.9) than non-smokers (112.9 months; 95% CI: 107.3-118.5, p=0.001). No significant difference was observed in tumor staging between the groups.
Conclusion: Smoking is associated with increased EX and reduced survival in CRC patients. These findings emphasize the importance of smoking cessation in CRC management and suggest that smoking history should be considered in risk stratification and follow-up planning.

Keywords

Colorectal cancer , extranodal extension , smoking , survival , tumor staging

References

• Siegel RL, Miller KD, Jemal A. Cancer statistics, 2020. CA Cancer J Clin. 2020;70(1):7-30. doi:10.3322/caac.21590
• Wieser J, Hoffmeister M, Brenner H, Mons U. Associations of alcohol use and smoking with early-onset colorectal cancer-a systematic review and meta-analysis. Clin Colorectal Cancer. 2025;24(3):331-340.e15. doi: 10.1016/j.clcc.2025.05.002
• Bai X, Wei H, Liu W, et al. Cigarette smoke promotes colorectal cancer through modulation of gut microbiota and related metabolites. Gut. 2022;71(12):2439-2450. doi:10.1136/gutjnl-2021-325021
• Feldman D, Rodgers-Fouche L, Hicks S, Chung DC. Clinical features and long-term outcomes of patients with colonic oligopolyposis of unknown etiology. World J Gastroenterol. 2022;28(48):6950-6961. doi:10.3748/wjg.v28.i48.6950
• Islami F, Marlow EC, Thomson B, et al. Proportion and number of cancer cases and deaths attributable to potentially modifiable risk factors in the United States, 2019. CA Cancer J Clin. 2024;74(5):405-432. doi:10.3322/caac.21858
• Huang YM, Wei PL, Ho CH, Yeh CC. Cigarette smoking associated with colorectal cancer survival: a nationwide, population-based cohort study. J Clin Med. 2022;11(4):913. doi:10.3390/jcm11040913
• Yuan C, Morales-Oyarvide V, Babic A, et al. Cigarette smoking and pancreatic cancer survival. J Clin Oncol. 2017;35(16):1822-1828. doi:10. 1200/JCO.2016.71.2026
• Tu H, Ye Y, Huang M, et al. Smoking, smoking cessation, and survival after cancer diagnosis in 128,423 patients across cancer types. Cancer Commun (Lond). 2022;42(12):1421-1424. doi:10.1002/cac2.12357
• Sohrab SS, Raj R, Nagar A, et al. Chronic inflammation's transformation to cancer: a nanotherapeutic paradigm. Molecules. 2023;28(11):4413. doi:10.3390/molecules28114413
• Keivanlou MH, Amini-Salehi E, Hassanipour S, et al. Association between smoking and colorectal cancer in Eastern Mediterranean Regional Office (EMRO): a systematic review and meta-analysis. Saudi J Gastroenterol. 2023;29(4):204-211. doi:10.4103/sjg.sjg_163_23
• Makino A, Tsuruta M, Okabayashi K, et al. The impact of smoking on pulmonary metastasis in colorectal cancer. Onco Targets Ther. 2020;13: 9623-9629. doi:10.2147/OTT.S263250
• Huang YM, Wei PL, Ho CH, Yeh CC. Cigarette smoking associated with colorectal cancer survival: a nationwide, population-based cohort study. J Clin Med. 2022;11(4):913. doi:10.3390/jcm11040913
• Parsons A, Daley A, Begh R, Aveyard P. Influence of smoking cessation after diagnosis of early stage lung cancer on prognosis: systematic review of observational studies with meta-analysis. BMJ. 2010;340:b5569. doi:10.1136/bmj.b5569
• Alwers E, Carr PR, Banbury B, et al. Smoking behavior and prognosis after colorectal cancer diagnosis: a pooled analysis of 11 studies. JNCI Cancer Spectr. 2021;5(5):pkab077. doi:10.1093/jncics/pkab077
• Gram IT, Park SY, Wilkens LR, Haiman CA, Le Marchand L. Smoking-related risks of colorectal cancer by anatomical subsite and sex. Am J Epidemiol. 2020;189(6):543-553. doi:10.1093/aje/kwaa005
• Darmon S, Park A, Lovejoy LA, Shriver CD, Zhu K, Ellsworth RE. Relationship between cigarette smoking and cancer characteristics and survival among breast cancer patients. Int J Environ Res Public Health. 2022;19(7):4084. doi:10.3390/ijerph19074084
• Devall M, Dampier CH, Eaton S, et al. Novel insights into the molecular mechanisms underlying risk of colorectal cancer from smoking and red/processed meat carcinogens by modeling exposure in normal colon organoids. Oncotarget. 2021;12(19):1863-1877. doi:10.18632/oncotarget. 28058
• Jung YS, Kim NH, Yang HJ, et al. The impact of passive smoking on the risk of colorectal neoplasia in never, former, and current smokers. J Gastroenterol Hepatol. 2018;33(5):1023-1030. doi:10.1111/jgh.14023