Being obese or underweight is linked to a worse prognosis among people with multiple myeloma, according to a study published in Blood Cancer Journal.
Researchers at the Memorial Sloan Kettering Cancer Center found that underweight or severely obese people who are diagnosed with multiple myeloma (MM) experience a faster progression of the disease or death compared with those with a normal body mass index (BMI).
The study, led by Dr. Urvi Shah and colleagues, looked at data from more than 1000 newly diagnosed patients with MM in the Multiple Myeloma Research Foundation database to find out how BMI affects the prognosis of this patient population.
Sixty-one percent of newly diagnosed patients with MM were men, and 39% were women. The patients were primarily White (66%) and had a median age of 63 years.
Of the participants in the study, 2% were classified as underweight, with a BMI of less than 18.5, while 30% were classified as normal weight, with a BMI ranging from 18.5 to 24.0.
Most patients in the study fell on the higher end of the BMI scale. Specifically, 38.2% were classified as overweight, with a BMI between 25 and 29; 17.9% were moderately obese, with a BMI between 30 and 34; and 11.9% were severely obese, with a BMI of 35 or higher.
The researchers observed that White and Black patients were more likely to have a higher-than-normal BMI than patients of other races.
Dr. Urvi Shah and colleagues evaluated how well cancer patients could function daily using the Eastern Cooperative Oncology Group (ECOG) performance status tool. A higher ECOG score usually means the cancer is more advanced, or the prognosis may be poorer, and they wanted to see how BMI might affect this measure.
The study revealed that underweight and severely obese patients were more likely to have a higher ECOG score, reflecting a worse functional status.
In addition, over more than 2 years of follow-up, the researchers found that patients who were underweight or severely obese had a shorter time on average before their disease progressed or resulted in death compared with patients who were of normal weight, overweight, or moderately obese.
After considering other clinical factors that could affect the outcome, the researchers determined that underweight patient had a significantly higher risk of death, approximately 2.3 times higher than patients with a normal weight. However, for severely obese patients, the findings did not reveal statistical significance.
“We speculate that the observed adverse outcomes in underweight patients may be due to high ECOG [scores] (ie, poor performance status) and disease-related weight loss,” the researchers wrote.
They suggested that the potentially higher risk of death in underweight patients could be attributed to increased fat cells that create a favorable environment for myeloma growth. However, they also noted that the worse ECOG status, which reflects functional ability, could contribute to this increased risk.
Source: Myeloma Research News