Obesity Increases the Risk for High-Grade Prostate Cancer: Results from the REDUCE Study

Adriana C. Vidal; Lauren E. Howard; Daniel M. Moreira; Ramiro Castro-Santamaria; Gerald L. Andriole; Stephen J. Freedland

doi:10.1158/1055-9965.EPI-14-0795

DOI: 10.1158/1055-9965.EPI-14-0795 Published December 2014

Article Figures & Data

Tables

Table 1.

Clinical characteristics of men in the REDUCE trial who had at least one on-study biopsy stratified by obesity status

	Normal weight <25 kg/m²	Overweight 25–29.9 kg/m²	Obese ≥30 kg/m²	P^a
Number of patients (%)	1,739 (27)	3,384 (53)	1,304 (20)
Age, median (IQR; y)	64 (59–68)	63 (58–67)	62 (57–66)	0.0001
PSA, median (IQR), ng/mL	5.8 (4.5–7.4)	5.7 (4.4–7.3)	5.7 (4.3–7.3)	0.06
Race, n (%)				0.002†
White	1,561 (90)	3,136 (93)	1,197 (92)
Black	33 (2)	56 (2)	30 (2)
Other	145 (8)	192 (6)	77 (6)
DRE findings, n (%)				0.58†
Not suspicious	1,669 (96)	3,265 (96)	1,252 (96)
Suspicious for cancer	70 (4)	119 (4)	52 (4)
TRUS volume, median (IQR), cc	41 (32–54)	44 (33–57)	46 (35–59)	0.0001
Total cores on baseline biopsy (IQR)	8 (6–10)	9 (6–10)	10 (6–10)	0.012
2-year biopsy type, n (%)				0.717†
Protocol-mandated	1,565 (90)	3,059 (90)	1,185 (91)
Off-study	174 (10)	325 (10)	119 (9)

↵^aP value assessed by the Kruskal–Wallis test unless otherwise specified.

Table 2.

ORs for the association between obesity and risk of overall, low-grade, and high-grade prostate cancer in the REDUCE study

	Overall cancer^b			Low-grade cancer^b Gleason (≤6)			High-grade cancer^b Gleason (≥7)
	Cases	OR^a (95% CI)	P	Cases	OR^a (95% CI)	P	Cases	OR^a (95% CI)	P
All men (N = 6,427)
Crude analysis	1,448 (23%)	0.84 (0.72–0.98)	0.022	1,008 (16%)	0.74 (0.62–0.89)	0.001	440 (7%)	1.08 (0.86–1.37)	0.50
Adjusted analysis^a		0.92 (0.79–1.07)	0.28		0.79 (0.65–0.94)	0.01		1.28 (1.01–1.63)	0.04
Placebo arm (N = 3,270)
Crude analysis	823 (25%)	0.84 (0.69–1.03)	0.10	594 (18%)	0.79 (0.62–0.99)	0.04	229 (7%)	0.99 (0.71–1.39)	0.98
Adjusted analysis^a		0.92 (0.75–1.13)	0.45		0.84 (0.66–1.06)	0.15		1.18 (0.84–1.66)	0.35
Dutasteride arm (N = 3,157)
Crude analysis	635 (20%)	0.83 (0.66–1.04)	0.11	414 (13%)	0.67 (0.50–0.89)	0.006	221 (7%)	1.18 (0.85–1.65)	0.32
Adjusted analysis^a		0.91 (0.73–1.15)	0.44		0.71 (0.53–0.95)	0.02		1.41 (1.00–1.98)	0.05

↵^aAdjusted for age, race, PSA, DRE findings, TRUS volume, and study treatment arm.
↵^bReferents were nonobese men (BMI <30 kg/m²) and no cancer.

Table 3.

ORs for the association between obesity and risk of overall, low-grade, and high-grade prostate cancer in the REDUCE study, stratified by median age

	Overall Cancer^b		Low-grade cancer^b Gleason (≤6)		High-grade cancer^b Gleason (≥7)
	OR^a (95% CI)	P	OR^a (95% CI)	P	OR^a (95% CI)	P
Obesity predicting cancer grade
Age <63	0.85 (0.68–1.06)	0.15	0.81 (0.62–1.05)	0.11	0.95 (0.64–1.42)	0.82
Age ≥63	0.99 (0.80–1.22)	0.90	0.77 (0.60–0.99)	0.04	1.55 (1.14–2.11)	0.005

NOTE: P_interaction between obesity and age is 0.12 for overall prostate cancer, 0.8 for low-grade prostate cancer, and 0.06 for high-grade prostate cancer.