Influence of obesity on biochemical and clinical failure after external‐beam radiotherapy for localized prostate cancer

Abstract

BACKGROUND. 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). METHODS. 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. RESULTS. 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). CONCLUSIONS. 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.

Influence of abdominal adiposity, waist circumference, and body mass index on clinical and pathologic findings in patients treated with radiotherapy for localized prostate cancer

“…Moreover, SAT volumes were generally found to be inversely correlated with age at diagnosis. These results are in agreement with other published studies, 5,8,9,43 suggesting that the development of prostate cancer may start earlier or progress more rapidly in obese patients. Conversely, this analysis did not reveal any association between the different anthropometric measures of obesity and adverse pathologic features of the tumor such as PSA, clinical T classification, or PPC, as observed in other studies.…”

“…Conversely, this analysis did not reveal any association between the different anthropometric measures of obesity and adverse pathologic features of the tumor such as PSA, clinical T classification, or PPC, as observed in other studies. 9,17,31 RT with concomitant ADT is the mainstay of therapy for men with locally advanced disease. 44,45 However, this treatment has been associated with an increased risk of diabetes and CVD, as observed in 2 large populationbased cohorts studies.…”

Body Mass Index, Weight Change, and Risk of Prostate Cancer in the Cancer Prevention Study II Nutrition Cohort

“…Indeed, despite the largely null association between obesity and overall prostate cancer risk, adult BMI has been associated with the risk of more advanced prostate cancer and prostate cancer mortality in seven out of nine prospective studies (12, 13, 23, 25-29; ref. 25 includes results from two cohorts), and with higher recurrence rates after radical prostatectomy or radiotherapy treatment (30)(31)(32)(33), suggesting that obesity may influence prostate cancer aggressiveness and progression.…”

Influence of body mass index on prostate‐specific antigen failure after androgen suppression and radiation therapy for localized prostate cancer

“…12,[14][15][16][17][18] Although the data after radiation therapy is limited, 1 recent report showed that BMI is a predictor of PSA failure among patients treated with external beam radiation therapy (EBRT) alone, 19 whereas another report suggested that this may not be true after brachytherapy. 20 The prognostic significance of BMI with regard to outcome after AST and RT has not been studied.…”