Obesity and long-term survival after radical prostatectomy.
OBJECTIVE
Obesity is a modifiable risk factor associated with worse outcomes for many cancers, yet implications for prostate cancer are not well understood. Notably the impact of body mass index on long-term survival after treatment is unclear. We performed a retrospective cohort study on a large series of men who underwent radical prostatectomy to assess the impact of obesity on long-term biochemical recurrence-free survival, prostate cancer specific survival and overall survival.


METHODS
Between 1982 and 2012, 11,152 men underwent radical prostatectomy at a single tertiary referral center. Patients were stratified according to body mass index as normal weight (body mass index less than 25 kg/m(2)), overweight (body mass index 25 to less than 30 kg/m(2)), mild obesity (body mass index 30 to less than 35 kg/m(2)) and moderate/severe obesity (body mass index 35 kg/m(2) or greater), comprising 27.6%, 56.0%, 14.1% and 2.3% of the cohort, respectively. Covariates included age, preoperative prostate specific antigen, surgery year, Gleason score, pathological stage, surgical margin and race. Predictors of biochemical recurrence-free survival, prostate cancer specific survival and overall survival were identified using Cox proportional hazard models.


RESULTS
Median followup was 5 years (range 1 to 27). Actuarial 20-year biochemical recurrence-free survival for mild and moderate/severe obesity was 65% and 51%, respectively, compared to 76% for normal weight men (p ≤0.001). In a multivariate model obesity was a significant predictor of biochemical recurrence-free survival (mild HR 1.30, p = 0.002; moderate/severe HR 1.45, p = 0.028) and overall survival (mild HR 1.41, p = 0.003; moderate/severe HR 1.81, p = 0.033). However, only mild obesity was significantly associated with prostate cancer specific survival (HR 1.51, p = 0.040), whereas moderate/severe obesity was not (HR 1.58, p = 0.356).


CONCLUSIONS
Obese men have higher rates of biochemical recurrence than normal weight patients during long-term followup. Obesity at the time of surgery independently predicts overall survival and biochemical recurrence-free survival but not prostate cancer specific survival.
James Buchanan Brady Urological Institute, Johns Hopkins Medical Institutions, Baltimore, Maryland, Seoul National University Boramae Hospital (SBL), Seoul, South Korea; Sungkyunkwan University Samsung Medical Center (BCJ), Seoul, South Korea; Duke University Medical Center, Durham, North Carolina (SJF).
Heather J
HJ
Chalfin
James Buchanan Brady Urological Institute, Johns Hopkins Medical Institutions, Baltimore, Maryland, Seoul National University Boramae Hospital (SBL), Seoul, South Korea; Sungkyunkwan University Samsung Medical Center (BCJ), Seoul, South Korea; Duke University Medical Center, Durham, North Carolina (SJF).
Seung Bae
SB
Lee
James Buchanan Brady Urological Institute, Johns Hopkins Medical Institutions, Baltimore, Maryland, Seoul National University Boramae Hospital (SBL), Seoul, South Korea; Sungkyunkwan University Samsung Medical Center (BCJ), Seoul, South Korea; Duke University Medical Center, Durham, North Carolina (SJF).
Byong Chang
BC
Jeong
James Buchanan Brady Urological Institute, Johns Hopkins Medical Institutions, Baltimore, Maryland, Seoul National University Boramae Hospital (SBL), Seoul, South Korea; Sungkyunkwan University Samsung Medical Center (BCJ), Seoul, South Korea; Duke University Medical Center, Durham, North Carolina (SJF).
Stephen J
SJ
Freedland
James Buchanan Brady Urological Institute, Johns Hopkins Medical Institutions, Baltimore, Maryland, Seoul National University Boramae Hospital (SBL), Seoul, South Korea; Sungkyunkwan University Samsung Medical Center (BCJ), Seoul, South Korea; Duke University Medical Center, Durham, North Carolina (SJF).
Hamid
H
Alai
James Buchanan Brady Urological Institute, Johns Hopkins Medical Institutions, Baltimore, Maryland, Seoul National University Boramae Hospital (SBL), Seoul, South Korea; Sungkyunkwan University Samsung Medical Center (BCJ), Seoul, South Korea; Duke University Medical Center, Durham, North Carolina (SJF).
Zhaoyong
Z
Feng
James Buchanan Brady Urological Institute, Johns Hopkins Medical Institutions, Baltimore, Maryland, Seoul National University Boramae Hospital (SBL), Seoul, South Korea; Sungkyunkwan University Samsung Medical Center (BCJ), Seoul, South Korea; Duke University Medical Center, Durham, North Carolina (SJF).
Bruce J
BJ
Trock
James Buchanan Brady Urological Institute, Johns Hopkins Medical Institutions, Baltimore, Maryland, Seoul National University Boramae Hospital (SBL), Seoul, South Korea; Sungkyunkwan University Samsung Medical Center (BCJ), Seoul, South Korea; Duke University Medical Center, Durham, North Carolina (SJF).
Alan W
AW
Partin
James Buchanan Brady Urological Institute, Johns Hopkins Medical Institutions, Baltimore, Maryland, Seoul National University Boramae Hospital (SBL), Seoul, South Korea; Sungkyunkwan University Samsung Medical Center (BCJ), Seoul, South Korea; Duke University Medical Center, Durham, North Carolina (SJF).
Elizabeth
E
Humphreys
James Buchanan Brady Urological Institute, Johns Hopkins Medical Institutions, Baltimore, Maryland, Seoul National University Boramae Hospital (SBL), Seoul, South Korea; Sungkyunkwan University Samsung Medical Center (BCJ), Seoul, South Korea; Duke University Medical Center, Durham, North Carolina (SJF).
Patrick C
PC
Walsh
James Buchanan Brady Urological Institute, Johns Hopkins Medical Institutions, Baltimore, Maryland, Seoul National University Boramae Hospital (SBL), Seoul, South Korea; Sungkyunkwan University Samsung Medical Center (BCJ), Seoul, South Korea; Duke University Medical Center, Durham, North Carolina (SJF). Electronic address: mhan1@jhmi.edu.
Misop
M
Han
D000230:Adenocarcinoma / Q000150:complications / Q000401:mortality / Q000601:surgery; D015992:Body Mass Index; D018572:Disease-Free Survival; D005500:Follow-Up Studies; D005544:Forecasting; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000401:mortality; D009765:Obesity / Q000150:complications / Q000401:mortality*; D011379:Prognosis; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000150:complications / Q000401:mortality / Q000601:surgery*; D056910:Republic of Korea / Q000453:epidemiology; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends
body mass index; mortality; obesity; prostatectomy; prostatic neoplasms