Association between Body Mass Index and Cancer Survival in a Pooled Analysis of 22 Clinical Trials

Abstract

BACKGROUND Data are inconsistent on the association between body mass index (BMI) at time of cancer diagnosis and prognosis. We used data from 22 clinical treatment trials to examine the association between BMI and survival across multiple cancer types and stages. METHODS Trials with ≥5 years of follow-up were selected. Patients with BMI<18.5kg/m2 were excluded. Within a disease, analyses were limited to patients on similar treatment regimens. Variable cutpoint analysis identified a BMI cutpoint that maximized differences in survival. Multivariable Cox regression analyses compared survival between patients with BMI above versus below the cutpoint, adjusting for age, race, sex, and important disease-specific clinical prognostic factors. RESULTS A total of 11,724 patients from 22 trials were identified. Fourteen analyses were performed by disease site and treatment regimen. A cutpoint of BMI=25kg/m2 maximized survival differences. No statistically significant trend across all 14 analyses was observed (mean HR=0.96, P=.06). In no cancer/treatment combination was elevated BMI associated with an increased risk of death; for some cancers there was a survival advantage for higher BMI. In sex-stratified analyses, BMI≥25kg/m2 was associated with better overall survival among men (HR=0.82; P=.003), but not women (HR=1.04; P=.86). The association persisted when sex-specific cancers were excluded, when treatment regimens were restricted to dose based on body-surface area, and when early stage cancers were excluded. CONCLUSION The association between BMI and survival is not consistent across cancer types and stages. IMPACT Our findings suggest that disease, stage, and gender specific body size recommendations for cancer survivors may be warranted.

The evolution of body composition in oncology—epidemiology, clinical trials, and the future of patient care: facts and numbers

“…10 It is estimated that 1 in 11 (9%) incident cancers diagnosed in North America and Europe is attributable to obesity. cancer diagnosis), and this was independently associated with improved overall survival in patients with several types of malignancies, including bladder 13 Other studies among a variety of cancer types have reported that a higher BMI is associated with improved overall survival ( Table 1). 12 In contrast to cancer incidence, the association between BMI and cancer prognosis (e.g.…”

“…Higher body mass index before diagnosis increases the risk of developing multiple cancers and higher body mass index at or after diagnosis lowers the risk of dying from multiple cancers. 13 The totality of these data suggests that BMI alone is insufficient and that more accurate measures of muscle and adipose tissue distribution may improve prognostication of outcomes. and cancer-specific survival in patients with cancer.…”

Association of body-mass index and outcomes in patients with metastatic melanoma treated with targeted therapy, immunotherapy, or chemotherapy: a retrospective, multicohort analysis

“…This phenomenon, wherein higher BMI is associated with increased disease risk but confers a survival advantage in patients with established or advanced disease, has recently been described in other malignancies. 7–9 Whether this inverse relationship is causal remains poorly understood. 10 However, several features of the current study suggest a potential biological role of adiposity in metastatic melanoma patient survival.…”

“…5,6 However, higher BMI has also been associated with improved outcomes in some cancers, 7–9 a phenomenon dubbed the “obesity paradox.” 10 The role of obesity in melanoma has not been well-studied to date. 5 Existing data suggests that obesity is associated with an increased risk of melanoma in men 11 and increased primary tumor Breslow thickness.…”

Clinical implications of low skeletal muscle mass in early-stage breast and colorectal cancer

“…15 Obesity is a well-established risk factor for breast cancer incidence and survival, but as described previously, although studies have clearly shown worse mortality with obesity, the association between breast cancer survival and overweight (BMI 25–30) have been less consistent, with some studies showing no adverse effect. 33–35 Body mass index only incompletely captures the more relevant physiologic measures of skeletal muscle and adipose tissue.…”