MONDAY, April 19, 2021 (HealthDay News) -- Most people know obesity can lead to diabetes or heart disease, but excess weight can play a role in cancer, too, researchers say.
A new study found that breast cancer survivors who are overweight have a statistically significant increased risk of developing a second primary cancer – one not connected to their previous cancer.
The risk likely owes to shared risk factors between the two cancers – of which obesity is one – as well as genetic susceptibility and long-term effects of breast cancer treatment, the study authors said.
"The risk is comparable to what we would see for an initial breast cancer," said Heather Spencer Feigelson, senior investigator at the Kaiser Permanente Colorado Institute for Health Research, in Aurora. "It's just another piece of evidence showing us how [excess weight] is really important."
For the study, the researchers reviewed data from nearly 6,500 women treated at Kaiser Permanente in Colorado and Washington state. Roughly equal percentages were normal weight, overweight and obese.
Women who had an invasive breast cancer had a small, but significantly higher risk for a second cancer as their body mass index (BMI) increased, the study found. (BMI is an estimate of body fat based on height and weight.