Cigarettes do not increase risk for disease recurrence after prostatectomy
MedWire News: Cigarette-smoking men who undergo radical prostatectomy (RP) for localized prostate cancer are not at increased risk for biochemical disease recurrence (BCR) after surgery compared with nonsmokers, US researchers report.
However, the study did show an association between smoking and more advanced disease, particularly among obese men.
Smoking has previously been correlated with an increased risk for cancer relapse and progression to disseminated disease, and two studies have indicated greater prostate cancer progression among smokers, compared with nonsmokers, after radiotherapy for localized tumors.
In this study, Daniel Moreira from Duke University School of Medicine in Durham, North Carolina, and colleagues analyzed the association between cigarette smoking and the interval to BCR after RP in 1267 patients from the Shared Equal Access Regional Cancer Hospital (SEARCH) cohort.
Among the cohort, 408 men were active smokers, while 859 were non- or ex-smokers. Active smokers were more likely to have a lower body mass index (BMI), in addition to signs of more advanced disease such as a greater percentage of positive biopsy cores, a higher preoperative prostate-specific antigen level, and more extracapsular extension of disease and seminal vesicle invasion.
The rates of BCR between smokers and nonsmokers were similar during the median follow-up of 37 months, with univariate analysis showing a nonsignificant 1.19-fold increase in BCR among smokers.
Multivariate analysis also showed the difference between smokers and nonsmokers with regard to BCR rates to be nonsignificant. However, smoking was found to significantly increase the risk for extracapsular extension of disease, which conferred a 1.61-fold increased risk for BCR.
Since previous analysis among the SEARCH cohort has revealed an association between BMI and decreased BCR, and the smokers in the current study had lower BMI, the researchers adjusted their results for this factor only. This revealed a significant 1.37-fold increase in the risk for BCR among smokers, compared with nonsmokers.
After further stratifying the results for obesity, Moreira and team found that obese smokers had a greater risk for BCR compared with obese nonsmokers, leading them to suggest that “the combination of obesity and smoking could result in a particularly aggressive cancer.”
They conclude: “It is likely that a combination of these biologic and behavioral factors is responsible for the association between smoking and aggressive prostate cancer.”
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By Sarah Guy