Objective: To investigate the effect of smoking on the outcome in a cohort of men treated for localized prostate cancer at one institution with a uniform protocol of radical external beam radiotherapy (EBRT).
Patients and methods: The study was a retrospective review of 434 patients with cT1-T4 N0m0 prostate cancer treated with curative intent with EBRT (66 Gy in 33 fractions) between 1990 and 1999. Univariate and multivariate Cox regression analyses were used to estimate the risk associated with smoking on biochemical failure (American Society for Therapeutic Radiology and Oncology definition), local failure, distant failure, overall and disease-specific survival.
Results: The median follow-up was 70.3 months. A smoking history was obtained in 96% of cases; 16.8% were current smokers, 54.4% previous smokers and 28.8% non-smokers. Current smokers presented at a younger median age, by 3.6 years (P = 0.06). There were no differences in clinical T stage, Gleason score or prostate-specific antigen level amongst the three patient groups. Smoking conferred a higher risk of developing metastatic disease in both current smokers (hazard ratio 5.24; 95% confidence interval 1.75-15.72) and previous smokers (2.90, 1.09-7.67). There were also increases in risk, although not quite significant, for biochemical failure (1.49, 0.88-2.40) and overall survival (1.72, 0.94-3.15).
Conclusions: After curative treatment with EBRT, a history of smoking was associated with a greater risk of developing metastatic disease. Smoking status was not associated with worse disease on presentation.