Association of Cigarette Smoking With Interval to Biochemical Recurrence After Radical Prostatectomy: Results from the SEARCH Database

ObjectivesTo analyze the association between cigarette smoking and biochemical recurrence (BCR) after radical prostatectomy among men from the Shared Equal Access Regional Cancer Hospital (SEARCH) cohort.MethodsWe performed a retrospective analysis of 1267 subjects from the SEARCH cohort treated from 1998 to 2008 with smoking status available from the preoperative notes. A comparison of the baseline patient and disease characteristics between the current smokers and nonsmokers (past and never smokers combined) was performed using the chi-square and rank sum tests. The univariate and multivariate associations between smoking status and BCR-free survival were analyzed using Kaplan-Meier plots, the log-rank test, and Cox proportional hazard models.ResultsOf the 1267 patients, 408 (32%) were active smokers and 859 (68%) were nonsmokers at surgery. The current smokers were younger (P <.001), more likely to be black (P <.001), and had a lower body mass index (P <.001), a greater percentage of positive biopsy cores (P = .039), a greater preoperative prostate-specific antigen level (P = .003), more extracapsular extension (P = .003) and seminal vesicle invasion (P = .029), and lower prostate volumes (P = .002). On univariate analysis, smokers had a risk of BCR similar to that of nonsmokers (hazard ratio 1.19, P = .129). On multivariate analysis, smoking was associated with an increased risk of BCR when adjusted for body mass index only (hazard ratio 1.37, P = .008). However, after adjustment for multiple preoperative characteristics, the association was attenuated and no longer statistically significant (hazard ratio 1.12, P = .325). After additional adjustment for postoperative features, such as tumor grade and stage, smoking was unrelated to the risk of BCR (hazard ratio 0.91, P = .502).ConclusionsAmong patients undergoing radical prostatectomy in the SEARCH cohort, cigarette smoking was associated with slightly more advanced disease but a similar risk of BCR.