By Martin S. Lipsky, MD
Chancellor, South Jordan Campus, Roseman University of Health Sciences, South Jordan, UT
Dr. Lipsky is a retained consultant for Health Solutions & Strategies.
SYNOPSIS: While smoking is associated with a wide range of cancers, the link between prostate cancer and smoking is tenuous. This study showed that following prostatectomy for cancer, smokers and ex-smokers had a higher risk of recurrence.
SOURCE: Rieken M, et al. Association of cigarette smoking and smoking cessation with biochemical recurrence of prostate cancer in patients treated with radical prostatectomy. Eur Urol 2015 Jun 3. pii: S0302-2838(15)00440-6. doi: 10.1016/j.eururo.2015.05.038 [Epub ahead of print].
Smoking is a well-known risk factor for many types of cancer. However, evidence establishing a link between smoking and the incidence of prostate cancer is tenuous and often contradictory.1 While the association between smoking and the incidence of prostate cancer remains unclear, cigarette smoking does seem to be a dose-dependent risk factor for prostate cancer mortality.1
In this multi-institution study, Rieken et al investigated the association between smoking status, time since smoking cessation and cumulative smoking, and the risk of biochemical recurrence of prostate cancer in patients treated with radical prostatectomy for prostate cancer.2
Using six centers, the cohort included 7426 patients with prostate cancer treated with radical prostatectomy from 2000 to 2011. Patients with incomplete data and those with positive lymph node metastases were excluded from the study, leaving 6538 patients available for analysis. Follow-up was performed according to institutional protocols, but generally patients were seen quarterly in the first year, semiannually in year two, and then annually. The primary endpoint was defined as a PSA > 0.2 ng/mL on two consecutive tests. The day an elevation was first detected was defined as the day of a recurrence. If patients died during the study, they were only considered as recurrent if the PSA was elevated before death. No patients received radiation, hormonal, or chemotherapy.
The mean duration for patients not experiencing a biochemical recurrence was 28 months (range 14-42 months). Smoking status was significantly associated with biochemical recurrence (BCR)-free survival, with BCR-free survival rates of 90%, 84%, and 83% in never, former, and current smokers, respectively. A significant association between smoking and a higher risk of recurrence was observed for all Gleason scores. No significant association with cumulative smoking and recurrence was found. Smoking cessation was associated with a reduced risk of recurrence.
The authors concluded that smoking status was associated with a higher risk of recurrence, with former and current smokers experiencing almost a two-fold increase in risk. The duration of time since an individual stopped smoking also was associated with recurrence risk. Those who stopped smoking < 10 years ago experienced an increased risk while those > 10 years was similar to nonsmokers.
COMMENTARY
This study provides yet another reason not to smoke. While it is not clear how and to what amount smoking contributes to an increased incidence of prostate cancer, smoking increases the risk of dying from prostate cancer. Smokers should be counseled regarding the connection of prostate cancer mortality and smoking. In primary care, physicians need to take advantage of “teachable moments,” when patients are most likely to listen and act on lifestyle advice. For cardiovascular disease, hospitalization for a cardiovascular event provides that moment when patients are more motivated to adjust to a healthier lifestyle. In addition to routinely counseling about tobacco use, perhaps undergoing a prostate biopsy or cystoscopy to rule out bladder cancer provides another teachable moment in the battle against tobacco use.
REFERENCES
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Islami F, et al. A systematic review and meta-analysis of tobacco use and prostate cancer mortality and incidence in prospective cohort studies. Eur Urol 2014 Dec;66:1054-64. doi: 10.1016/j.eururo.2014.08.059. Epub 2014 Sep 18.
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Rieken M, et. al. Association of cigarette smoking and smoking cessation with biochemical recurrence of prostate cancer in patients treated with radical prostatectomy. Eur Urol 2015 Jun 3. pii: S0302-2838(15)00440-6. doi: 10.1016/j.eururo.2015.05.038.
