Does Obesity Impact Treatment Outcome for Prostate Cancer Patients Treated with Radiotherapy: The Weighted Debate

Abstract

Background: There is conflicting evidence in the literature for the impact of obesity on treatment outcome for prostate cancer patients treated with radiotherapy. The first aim of this study is to identify if obesity negatively impacts on treatment outcome for obese prostate cancer patients treated with radiation therapy. The second aim of this study is to compare the treatment modalities used to treat obese and non-obese prostate cancer patients to establish if there is a benefit in treatment outcome when using particular treatment modalities for BMI groups. Materials and Methods: A database search using PubMed, Embase, The Cochrane Library and Science direct was performed to search articles published 2003-2013. Articles were selected based on relevancy, content and quality. Results: Eighteen articles and 25,397 patients were included in this review collectively. Radiation therapy treatment methods included brachytherapy, 3-dimentional conformal radiotherapy, intensity modulated radiotherapy and tomotherapy. Studies using conformal external beam radiotherapy techniques, image guided radiotherapy, hypofractionated regimes or brachytherapy show little or no impact of obesity on treatment outcome or toxicity. Studies using non-conformal techniques, lower total doses and poor image guided radiotherapy (IGRT) show inferior treatment outcome and increased toxicity for obese prostate cancer patients treated with radiation therapy. Conclusion: Greater BMI is associated with decreased overall survival. However, the negative impact of obesity on radiation induced toxicity, biochemical relapse and prostate cancer specific mortality may be prevented if treatment includes brachytherapy, IGRT, hypofractionated regimes and conformal radiotherapy techniques. Future studies are needed to establish individualised treatment protocol for obese patients.