Study finds high rates of increasing obesity in patients with history of cancer

A study at Columbia University's Mailman School of Public Health showed that obesity was more prevalent in patients with a history of cancer than in the general population, and survivors of colorectal and breast cancers were particularly affected. The study is among the first to compare rates of obesity among U.S. cancer survivors and adults without a history of cancer. Findings are published online in the Journal of Clinical Oncology.

Results were based on data from a nationally representative sample of 538,969 non-institutionalized adults aged 18 to 85 years with or without a history of cancer who participated in the annual National Health Interview Survey from 1997 to 2014. Obesity was defined as body mass index ? 30 kg/m2 for non-Asians and ? 27.5 kg/m2 for Asians.

Among 32,447 cancer survivors, the most common diagnoses were cancers of the breast followed by prostate, and colorectal cancers. Populations with the highest rates of increasing obesity were colorectal cancer survivors followed by breast cancer survivors. African-American survivors of all three cancers were particularly affected.

"Our study identified characteristics of cancer survivors at the highest risk of obesity, which are important patient populations in which oncology care providers should focus their efforts," said Heather Greenlee, ND, PhD, assistant professor of Epidemiology at the Mailman School, and principal investigator.

From 1997 to 2014, prevalence of obesity increased from 22 percent to 32 percent in cancer survivors and from 21 percent to 29 percent of adults without a history of cancer. During this time, rates of obesity grew more rapidly in women cancer compared to both male cancer survivors and compared to women with no history of cancer.

In female colorectal cancer survivors, those who are young and non-Hispanic black and had been diagnosed within 2 to 9 years had the highest increasing rates of obesity. Similarly, among female breast cancer survivors, those who are young, were diagnosed within the past year, and are non-Hispanic white had the highest increasing obesity rate. Among male colorectal cancer survivors, the highest increases in obesity were among older men, non-Hispanic blacks, and those at or greater than 10 years from diagnosis. In contrast, prostate-cancer survivors with the highest increases in obesity were younger, non-Hispanic whites, and 2 to 9 years from diagnosis.

"While our findings can be partially explained by the growing population of patients with breast and colorectal cancer - the two cancers most closely linked to obesity -- we identified additional populations of cancer survivors at risk of obesity not as well understood and which require further study," observed Dr. Greenlee.

"These results suggest that obesity is a growing public health burden for cancer survivors, which requires targeted interventions including weight management efforts to stave off the increasing obesity trends we are seeing in cancer survivors," noted Dr. Greenlee.