‘Overweight’ BMI linked to better outcomes with chemoradiotherapy for head and neck cancer

ByJennifer R. Southall

Fact checked byMindy Valcarcel, MS

Key takeaways:

Researchers observed a favorable association between BMI in the overweight range and 5-year OS and PFS.
Having overweight appeared associated with decreased 5-year locoregional failure, but not distant failure.

BMI in the overweight range appeared independently associated with favorable outcomes among patients who underwent chemoradiotherapy for nonmetastatic head and neck cancer, according to study results published in JAMA Network Open.

Researchers recommended additional research to improve understanding of the role of BMI among this patient population.

Overweight_scale_tape_268233374 — Patients with head and neck cancer who had a BMI in the overweight range had more favorable outcomes than those with BMI in the obese or normal range, study results showed. *Image: Adobe Stock*

“There is a complex interaction between cancer and the patient’s weight, nutritional status and muscle mass,” Sung Jun Ma, MD, resident physician in radiation oncology at Roswell Park Comprehensive Cancer Center, said in a press release. “For some reason, the same cancer in patients with normal BMI may behave more aggressively than in patients with overweight BMI, even if they receive the same treatments. Those with normal BMI may need more-intensive interventions to improve their outcomes.”

Rationale and methodology

Ma and colleagues sought to evaluate the role of normal vs. overweight or obese BMI in treatment response, tumor recurrence and survival outcomes among patients with nonmetastatic head and neck cancer undergoing chemoradiotherapy.

The retrospective, observational, single-institution cohort study included 445 patients (median age, 61 years; 83.8% men) who received chemoradiotherapy at a comprehensive cancer center between Jan. 1, 2005, and Jan. 31, 2021.

Main outcomes included metabolic response after treatment, locoregional failure, distant failure, OS and PFS.

Median follow-up was 48.1 months.

Findings

Overall, 40.2% of patients had overweight BMI, followed by 35.7% of patients with obese BMI and 24% with normal BMI.

Results of multivariable analysis showed a favorable association between overweight BMI only and improvements in rates of 5-year OS (71.5% vs. 58.4%; adjusted HR = 0.59; 95% CI, 0.39-0.91) and 5-year PFS (68.3% vs. 50.8%; adjusted HR = 0.51; 95% CI, 0.34-0.75).

Moreover, results of logistic multivariable analysis showed an association between overweight and obese BMI and complete metabolic response on follow-up PET–CT after treatments (overweight BMI: 91.6% vs. 73.8%; adjusted OR = 0.86; 95% CI, 0.8-0.93; obese BMI: 90.6% vs. 73.8%; adjusted OR = 0.89; 95% CI, 0.81-0.96).

Results of Fine-Gray multivariable analysis also showed an association between overweight BMI and decreased rates of 5-year locoregional failure (7% vs. 25.9%; adjusted HR = 0.3; 95% CI, 0.12-0.71), but not 5-year distant failure (17.4% vs. 21.5%; adjusted HR = 0.92; 95% CI, 0.47-1.77).

Researchers did not observe an association between obese BMI and rates of 5-year locoregional failure (10.4% vs. 25.9%; adjusted HR = 0.63; 95% CI, 0.29-1.37) or 5-year distant failure (15% vs. 21.5%; adjusted HR = 0.7; 95% CI, 0.35-1.38).

Implications

The finding of an association of overweight BMI with improved survival aligned with a growing body of literature suggesting higher BMI as a favorable prognostic factor, according to the researchers.

“However, obese BMI was not associated with OS in our study,” they wrote. “This finding is consistent with several reports, whereas other studies have reported survival benefits associated with obese BMI. Such discrepancies may be due to a nonlinear association between BMI and survival, with the highest survival seen in the overweight BMI range.”