Tobacco smoking and long-lasting symptoms from the bowel and the anal-sphincter region after radiotherapy for prostate cancer

Background and purpose: Tobacco smoking can cause vascular injury, tissue hypoxia and fibrosis as can ionizing radiation. However, we do not know if tobacco smoking increases the risk of long-term side effects after radiotherapy for prostate cancer.

Methods: We identified 985 men treated with radiotherapy for prostate cancer between 1993 and 2006. In 2008, long-lasting symptoms appearing after radiotherapy for prostate cancer were assessed through a study-specific questionnaire as were smoking habits and demographic factors of all these men. In the questionnaire the prostate-cancer survivors were asked to report symptom occurrence the previous six months.

Results: We obtained information on tobacco smoking from 836 of the 985 prostate-cancer survivors with a median time to follow-up of six years (range 2-14 years). The prevalence ratio of defecation urgency among current smokers compared to never smokers was 1.6 (95% CI 1.2-2.2). Corresponding prevalence ratio for diarrhea was 2.8 (95% CI 1.2-6.5), the sensation of bowel not completely emptied after defecation 2.1 (95% CI 1.3-3.3) and for sudden emptying of all stools into clothing without forewarning 4.7 (95% CI 2.3-9.7).

Conclusion: Tobacco smoking among prostate-cancer survivors treated with radiotherapy increases the risk of certain long-lasting symptoms from the bowel and anal-sphincter region.