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Influence of obesity on biochemical and clinical failure after external-beam radiotherapy for localized prostate cancer†
Article first published online: 26 JUN 2006
Copyright © 2006 American Cancer Society
Volume 107, Issue 3, pages 631–639, 1 August 2006
How to Cite
Strom, S. S., Kamat, A. M., Gruschkus, S. K., Gu, Y., Wen, S., Cheung, M. R., Pisters, L. L., Lee, A. K., Rosser, C. J. and Kuban, D. A. (2006), Influence of obesity on biochemical and clinical failure after external-beam radiotherapy for localized prostate cancer. Cancer, 107: 631–639. doi: 10.1002/cncr.22025
Results from the study were presented at the 2005 Genitourinary SPORE meeting (February 1, 2005) and seminars at the Mayo Clinic (November 7, 2004) and Fred Hutchinson Cancer Research Center (April 20, 2005).
- Issue published online: 18 JUL 2006
- Article first published online: 26 JUN 2006
- Manuscript Accepted: 20 MAR 2006
- Manuscript Revised: 2 FEB 2006
- Manuscript Received: 12 DEC 2005
- National Cancer Institute (NCI). Grant Numbers: CA84964, CA90270, NIEHS ES07784
- prostate cancer;
- biochemical failure;
- clinical recurrence
Several reports have shown that obesity is associated with increased risk of biochemical failure after radical prostatectomy. However, limited information is available regarding the impact of obesity on prostate cancer progression after radiotherapy. The current study sought to determine whether obesity was an independent predictor of biochemical failure (BF) and clinical recurrence (CF) among patients treated with external-beam radiotherapy (EBRT).
A retrospective analysis was performed on 873 patients receiving EBRT as the sole treatment for localized prostate cancer between 1988 and 2001. The Kaplan–Meier method, log-rank test, and Cox proportional hazards analyses were performed.
Of the 873 patients, 18% were mildly obese and 5% were moderately to severely obese. Obesity was related to younger age at diagnosis (P < .001), more recent year of diagnosis (P = .03), and race (P = .03), with African-American men having the highest obesity rates. During a mean follow-up of 96 months, 295 patients experienced BF and 127 had CF. On multivariate analysis, controlling for clinical and treatment characteristics, increased body mass index (BMI) significantly predicted BF (hazards ratio [HR] = 1.04; 95% confidence interval [95% CI], 1.02–1.07) with a positive trend by BMI category (P = .001). Similar results were found when the outcome was CF; BMI remained an independent predictor of progression (HR = 1.05; 95% CI, 1.01–1.09), with a statistically significant trend by increased BMI category (P = .03).
The current findings validate the important role of obesity, not only on BF but also on CF, and suggest a link to the biologic basis of tumor progression that can be therapeutically exploited. Cancer 2006. © 2006 American Cancer Society.