Regular use of aspirin after an advanced colorectal cancer (CRC) diagnosis may extend survival by as much as 14 months for patients with a healthy body mass index (BMI) score prediagnosis compared to those with obese BMIs, researchers reported in JAMA Network Open.

For the cross-sectional study, researchers used self-reported data from 656 patients with metastatic or treatment-refractory CRC to estimate the association of prediagnosis obesity and postdiagnosis aspirin use with overall survival. After controlling for age, sex, race, stage at initial diagnosis, and weight change between prediagnosis and survey date, they found that patients with prediagnosis obesity (BMI ≥ 30) had a median overall survival (OS) of 36.1 months, those who were overweight (BMI = 25–30) had a median OS of 44.3 months, and those with normal weight (BMI < 25) had a median OS of 50.5 months.

They also looked at BMI changes after diagnosis. During the study period, 39.2% of patients with a healthy BMI, 29.4% of those who were overweight, and 13.3% of those with obesity gained weight. However, their analysis revealed an additional survival benefit for patients with at least a 10% weight gain compared to those who did not gain weight.

“This study provides intriguing evidence supporting the association of obesity with CRC biology,” the researchers wrote. “Importantly, our findings suggest prediagnosis BMI may be useful in identifying patients who may benefit from postdiagnosis aspirin use, even in the setting of metastatic CRC.”

The study findings underscore oncology nurses’ role in providing patient education on cancer prevention strategies, such as following the American Cancer Society’s guidelines for diet and physical activity, and supporting patients’ ability to maintain nutrition after diagnosis using the tools in ONS’s Nutrition Learning Library.