PURPOSE: Although the relationship between smoking and prostate cancer risk is inconsistent, some studies show that smoking is associated with prostate cancer mortality.
Whether this reflects delayed diagnosis or direct smoking-related effects is unknown. REDUCE, which followed biopsy-negative men with protocol-dictated prostate-specific antigen (PSA)-independent biopsies at 2 and 4 years, provides an opportunity to evaluate smoking and prostate cancer diagnosis with minimal confounding from screening biases.
EXPERIMENTAL DESIGN: Logistic regression was conducted to test the association between smoking and cancer on the first on-study biopsy (no cancer, low-grade Gleason 4-6, high-grade Gleason 7-10) in REDUCE.
RESULTS: Of 6,240 men with complete data and ≥1 on-study biopsy, 2,937 (45.8%) never smoked, 929 (14.5%) were current smokers, and 2,554 (39.8%) were former smokers. Among men with negative first on-study biopsies, smokers were 36% less likely to receive a second on-study biopsy (P < 0.001). At first on-study biopsy, 941 (14.7%) men had cancer. Both current and former smoking were not significantly associated with either total or low-grade prostate cancer (all P > 0.36). Current (OR = 1.44, P = 0.028) but not former smokers (OR = 1.21, P = 0.12) were at increased risk of high-grade disease. On secondary analysis, there was an interaction between smoking and body mass index (BMI; Pinteraction = 0.017): current smokers with BMI ≤ 25 kg/m2 had an increased risk of low-grade (OR = 1.54, P = 0.043) and high-grade disease (OR = 2.45, P = 0.002), with null associations for BMI ≥ 25 kg/m2.
CONCLUSION: Among men with elevated PSA and negative pre-study biopsy in REDUCE, in which biopsies were largely PSA independent, smoking was unrelated to overall prostate cancer diagnosis but was associated with increased risk of high-grade prostate cancer.
Ho T, Howard LE, Vidal AC, Gerber L, Moreira D, McKeever M, Andriole G, Castro-Santamaria R, Freedland SJ. Are you the author?
Duke University School of Medicine, Durham, North Carolina; Urology Section, Durham Veterans Affairs Medical Center, Durham, North Carolina; Division of Urology, Department of Surgery, Duke Prostate Center, Duke University School of Medicine, Durham, North Carolina; Arthur Smith Institute for Urology, North Shore-Long Island Jewish Health System, New Hyde Park, New York; Division of Urologic Surgery, Department of Surgery, Washington University School of Medicine in St. Louis, St. Louis, Missouri; Prostate Study Center, Barnes-Jewish Hospital, St. Louis, Missouri; GlaxoSmithKline Oncology R&D, Collegeville, Pennsylvania; Division of Urology, Department of Surgery, Duke Prostate Center, Duke University School of Medicine, Durham, North Carolina; Department of Pathology, Duke University Medical Center, Durham, North Carolina.
Reference: Clin Cancer Res. 2014 Aug 19. Epub ahead of print.