Effect of BMI on primary treatment of prostate cancer.
OBJECTIVE
Obese patients with prostate cancer have more aggressive tumors and, in some studies, more prostate cancer-specific deaths. This study was designed to assess the relationship between body mass index (BMI) and treatment patterns of prostate cancer patients.


METHODS
We identified 5041 men with clinically localized prostate cancer (T1-3a, N0M0) who received their first treatment between 1995 and 2006. We derived the odds ratios (OR) for the likelihood of receiving each type of therapy compared with radical prostatectomy by BMI categories using multinomial logistic regression. In our analysis we controlled for age at diagnosis, race/ethnicity, education level, clinical risk category, and number of co-morbidities.


RESULTS
A total of 28.1% of patients were classified as normal BMI, 50.5% were overweight, 16.5% were obese, and 4.8% were very obese. The adjusted OR of receiving nonsurgical therapies (brachytherapy, external radiation, primary androgen deprivation, and active surveillance) increased relative to radical prostatectomy for increasing obesity (P = 0.003). Compared with the patients with normal BMI, very obese patients were more likely to receive brachytherapy (OR 1.59, 95% confidence interval [CI] 1.01 to 2.52), external radiation (OR 1.29, 95% CI 0.73 to 2.26), primary androgen therapy only (OR 1.77, 95% CI 1.12 to 2.81), and active surveillance (OR 1.06, 95% CI 0.52 to 2.17) compared with radical prostatectomy.


CONCLUSIONS
In a large cohort of American prostate cancer patients, a significant trend toward nonsurgical treatment modalities was apparent with increasing BMI.
Davies
Benjamin J
BJ
Department of Urology, Urology Outcomes Research Group, University of California-San Francisco Comprehensive Cancer Center, University of California, San Francisco 94143-1695, USA. bdavies@urology.ucsf.edu
Walsh
Thomas J
TJ
Ross
Phil L
PL
Knight
Sara J
SJ
Sadetsky
Natalia
N
Carroll
Peter R
PR
Kane
Christopher J
CJ
D000368:Aged; D015992:Body Mass Index; D003131:Combined Modality Therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009765:Obesity / Q000150:complications; D011446:Prospective Studies; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000473:pathology* / Q000601:surgery / Q000628:therapy*; D012307:Risk Factors; D016896:Treatment Outcome