Obesity, Male Gender May Improve Survival Outcomes with Targeted and Immunotherapy in Melanoma

Being obese may lead to improved survival outcomes among male patients with metastatic melanoma treated with targeted or immune therapies compared with patients with a normal body-mass index (BMI), according to a study published in Lancet Oncology.

Obesity has been associated with worse survival in various cancers, but its impact on mortality among patients with melanoma is unknown.

For this retrospective study, investigators selected 6 cohort studies — which included 1918 patients — to analyze the relationship of BMI (normal, overweight, or obese) with survival outcomes among patients with metastatic melanoma who underwent targeted therapy (dabrafenib plus trametinib, vemurafenib plus cobimetinib), immunotherapy (eg, pembrolizumab, nivolumab, atezolizumab), or chemotherapy (dacarbazine).

Of the study population, 36% of patients were considered to have a normal BMI, 37% were overweight, and 27% were obese.

Analysis revealed that obese patients had improved survival (PFS: average adjusted hazard ratio [HR], 0.77; 95% CI, 0.66-0.90; OS: HR, 0.74; 95% CI, 0.58-0.95), but only among those who received targeted therapy (PFS: HR, 0.72; 95% CI, 0.57-0.91; OS: HR, 0.60; 95% CI, 0.45-0.79) or immunotherapy (PFS: HR, 0.75; 95% CI, 0.561-1.00; OS: HR, 0.64; 0.47-0.86).

A survival benefit was observed only among obese men; no such associations were observed among women.

No improvements in PFS or OS were observed among patients who received chemotherapy, regardless of BMI.

The authors concluded that “these results have implications for the design of future clinical trials for patients with metastatic melanoma and the magnitude of the benefit found supports further investigation of the underlying mechanism of these associations.”

Reference

McQuade JL, Daniel CR, Hess KR, et al. Association of body-mass index and outcomes in patients with metastatic melanoma treated with targeted therapy, immunotherapy, or chemotherapy; a retrospective, multicohort analysis. Lancet Oncol. doi: S1470-2045(18)30078-0 [Epub ahead of print 2018 Feb 12]