Investigators have found that patients with head and neck cancer who had an overweight body mass index (BMI) may have had better outcomes, longer overall and progression-free survival, and lower rates of locoregional failure than those with a normal or obese BMI, according to a new study published by Ma et al in JAMA Network Open. The new findings shed light on how BMI may impact treatment response, risk of recurrence, and survival in patients with head and neck cancer.
Background
BMI scores fall into four categories: underweight, a BMI of less than 18.5; normal weight, a BMI between 18.5 and 24.9; overweight, a BMI between 25.0 and 29.9; and obese, a BMI of 30.0 or higher. Both overweight and obesity are associated with high blood pressure, type 2 diabetes, coronary heart disease, strokes, and an increased risk of several types of cancer. It’s estimated that by 2030, nearly 50% of all U.S. adults will fall into the obese BMI range.
The investigators stressed that as a result of the growing rates of overweight and obesity, it may be imperative to better understand how excess weight impacts both the risk of cancer and treatment outcomes. Previous meta-analyses and prospective studies involving patients with cancer have linked excess body weight to a higher mortality rate. However, research has shown that patients with lung cancer or renal cell carcinoma and obesity tend to fare better than patients without obesity.
The effects of overweight and obesity on head and neck cancer have been less clear, especially in patients who receive a combination treatment such as chemoradiotherapy. Those patients often develop significant medical problems as a result of therapy—including weight loss and loss of muscle, which are associated with poorer prognoses.
Study Methods and Results
In the new study, the investigators analyzed the overall and progression-free survival rates of 445 patients with nonmetastatic head and neck cancer who were treated with chemoradiotherapy from 2005 to 2021—107 of whom had a normal BMI, 179 of whom had overweight, and 159 of whom had obesity. Because only a small number of eligible patients had underweight or were treated with surgery or radiation therapy alone, the investigators excluded them from the study. Treatment was interrupted for only three of the patients.
Positron-emission tomography–computed tomography imaging after treatment revealed that complete metabolic responses were higher in patients with overweight (91.6%) vs those with a normal BMI (73.8%) and were also higher in patients with obesity (90.6%) vs those with a normal BMI (73.8%). However, patients with overweight had a 5-year overall survival rate of 71.5%, a 5-year progression-free survival rate of 68.3%, and a locoregional failure rate of 7.0% vs 58.4%, 50.8%, and 25.9%, respectively, for those with a normal BMI.
“In other tumor types, obesity has been shown to be a negative factor, but in head and neck cancer, being overweight improved survival,” said senior study author Anurag Singh, MD, Professor of Oncology and Director of Radiation Research in the Department of Radiation Medicine, Director of Head & Neck and Lymphoma Radiation Services, Co-Leader of the Cancer Stress Biology Program at the Roswell Park Comprehensive Cancer Center.
The investigators noted that further studies may be needed to clarify how BMI affects patients with head and neck cancer.
“There is a complex interaction between cancer and the patient’s weight, nutritional status, and muscle mass,” emphasized lead study author Sung Jun Ma, MD, a resident physician in the Department of Radiation Medicine at the Roswell Park Comprehensive Cancer Center. “For some reason, the same cancer in patients with [a] normal BMI may behave more aggressively than in patients with [an] overweight BMI, even if they receive the same treatments. Those with [a] normal BMI may need more intensive interventions to improve their outcomes,” he concluded.
Disclosure: For full disclosures of the study authors, visit jamanetwork.com.
