The impact of body mass index on treatment outcomes for patients with low-intermediate risk prostate cancer

Abstract

BackgroundLittle is known about the relationship between preoperative body mass index and need for adjuvant radiation therapy (RT) following radical prostatectomy. The goal of this study was to evaluate the utility of body mass index in predicting adverse clinical outcomes which require adjuvant RT among men with organ-confined prostate cancer (PCa).MethodsWe used a prospective cohort of 1,170 low-intermediate PCa risk men who underwent radical prostatectomy and evaluated the effect of body mass index on adverse pathologic features and freedom from biochemical failure (FFbF). Clinical and pathologic variables were compared across the body mass index groups using an analysis of variance model for continuous variables or χ2 for categorical variables. Factors related to adverse pathologic features were examined using logistic regression models. Time to biochemical recurrence was compared across the groups using a log-rank survivorship analysis. Multivariable analysis predicting biochemical recurrence was conducted with a Cox proportional hazards model.ResultsPatients with elevated body mass index (defined as body mass index ≥25 kg/m2) had greater extraprostatic extension (p = 0.004), and positive surgical margins (p = 0.01). Elevated body mass index did not correlate with preoperative risk groupings (p = 0.94). However, when compared with non-obese patients (body mass index <30 kg/m2), obese patients (body mass index ≥30 kg/m2) were much more likely to have higher rate of adverse pathologic features (p = 0.006). In patients with low- and intermediate- risk disease, obesity was strongly associated with rate of pathologic upgrading of tumors (p = 0.01 and p = 0.02), respectively. After controlling for known preoperative risk factors, body mass index was independently associated with ≥2 adverse pathologic features (p = 0.002), an indicator for adjuvant RT as well as FFbF (p = 0.001).ConclusionsBody mass index of ≥30 kg/m2 is independently associated with adverse pathologic features, which is an indicator for additional RT, particularly in patients with low-intermediate risk disease. Future studies may determine if this select group of patients may be best treated with definitive RT to reduce toxicity from additional RT following radical prostatectomy. We propose including body mass index in clinical decision-making for appropriate treatment recommendation for patients with low-intermediate risk PCa.

Obese men undergoing radical prostatectomy: Is robotic or retropubic better to limit positive surgical margins? Results from SEARCH

“…Thus, one would predict obesity should be linked with PSMs, regardless of technique. Indeed, we 3 and others 4–7 previously found obesity was associated with PSMs in RRP. Consistent with this, in the current study, obesity was linked with overall PSMs and at all locations for RRP.…”

“…We previously reported an association between obesity and PSMs at all anatomical locations among men undergoing RRP in SEARCH, although that study was limited to RRP only 3 . Likewise, others also found that obesity is associated with PSMs for RRP 4–7 . In contrast, many studies found no association between BMI and PSMs for RALP 17,18 .…”

“…For example, in regard to RP, obese men are more likely to suffer from capsular incision, a sign of technical challenges 2 . Consistent with this, historically, obesity has been linked with an increased risk of PSMs at the time of RP 3–7 . However, much of the data supporting this link are based on RRP.…”

The impact of body mass index on dosimetric quality in low-dose-rate prostate brachytherapy

“…In addition to its association with biochemical failure after treatment, studies have also found an association between increased BMI and an advanced prostate tumor stage [5]. Furthermore, in a recently published study, patients with an elevated BMI were found to have a higher rate of adverse pathologic features such as extraprostatic extension and positive surgical margins [6]. With the high prevalence of both prostate cancer and obesity, the importance of adjusting current treatment modalities for obese patients with prostate cancer has become crucial for achieving long-term biochemical control in this cohort of patients.…”

Long-term supplementation of decaffeinated green tea extract does not modify body weight or abdominal obesity in a randomized trial of men at high risk for prostate cancer

“…Although a few recent reports have continued to report conflicting data on the association between obesity and prostate cancer(PCa) risk [ 2 – 9 ], other well-conducted studies continue to demonstrate this association. There is evidence demonstrating that metabolic abnormality characterized by abdominal obesity has a biological rationale for increased risk of diagnosis and aggressive prostate cancer [ 10 – 21 ]. More recently, Folke et al [ 4 ] reported results suggesting that obesity advances prostate carcinogenesis in men diagnosed with HGPIN.…”