Premium
Obese patients with castration‐resistant prostate cancer may be at a lower risk of all‐cause mortality: results from the Shared Equal Access Regional Cancer Hospital (SEARCH) database
Author(s) -
Vidal Adriana C.,
Howard Lauren E.,
Hoedt Amanda,
Kane Christopher J.,
Terris Martha K.,
Aronson William J.,
Cooperberg Matthew R.,
Amling Christopher L.,
Freedland Stephen J.
Publication year - 2018
Publication title -
bju international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.773
H-Index - 148
eISSN - 1464-410X
pISSN - 1464-4096
DOI - 10.1111/bju.14193
Subject(s) - medicine , prostate cancer , underweight , overweight , hazard ratio , body mass index , obesity , database , cancer , oncology , cancer registry , proportional hazards model , population , confounding , confidence interval , environmental health , computer science
Objective To assess whether obesity is associated with progression to metastasis, prostate cancer‐specific mortality (PCSM), and all‐cause mortality (ACM), in patients with non‐metastatic castration‐resistant prostate cancer (non‐mCRPC). At the population level, obesity is associated with prostate cancer mortality; however, some studies have found that higher body mass index (BMI) is associated with better long‐term prostate cancer outcomes amongst men with mCRPC. Patients and Methods We identified 1 192 patients with non‐mCRPC from the Shared Equal Access Regional Cancer Hospital (SEARCH) database. BMI was calculated from height and weight abstracted from the medical records at the time closest to but prior to CRPC diagnosis and categorised as underweight (<21 kg/m 2 ), normal weight (21–24.9 kg/m 2 ), overweight (25–29.9 kg/m 2 ), and obese (≥30 kg/m 2 ). Competing risks regression and Cox models were used to test associations between obesity and progression to metastasis, PCSM, and ACM, accounting for confounders. Results Overall, 51 (4%) men were underweight, 239 (25%) were normal weight, 464 (39%) were overweight, and 438 (37%) were obese. In adjusted analysis, higher BMI was significantly associated with reduced ACM (hazard ratio [HR] 0.98, P = 0.012) but not PCSM (HR 1.00, P = 0.737) or metastases (HR 0.99, P = 0.225). Likewise, when BMI was treated as a categorical variable in adjusted models, obesity was not associated with PCSM (HR 1.11, P = 0.436) or metastases (HR 1.06, P = 0.647), but was associated with decreased ACM (HR 0.79, P = 0.016) compared to normal weight. No data were available on treatments received after CRPC diagnosis. Conclusions Amongst patients with non‐mCRPC obesity was associated with better overall survival. Although this result mirrors evidence from men with mCRPC, obesity was not associated with prostate cancer outcomes. Larger studies are needed to confirm these findings.