By Sara Bondell - May 03, 2021
Breast cancer survivors are at increased risk for developing second primary cancers compared to the general population. But what role does body mass index play in cancer recurrence or the development of a secondary cancer?
A study published in the Journal of the National Cancer Institute found that breast cancer survivors who are overweight have a significantly higher risk of developing a secondary primary cancer, or a cancer that is not connected to their previous one.
Investigators reviewed data from about 6,500 women and found nearly 13% developed a second cancer after an average follow-up period of seven years. Of those, almost 62% were an obesity-related cancer and 40% were a secondary breast cancer. The link between obesity and cancer was strongest in estrogen receptor-positive second breast cancer. Other obesity-related cancers included colorectal cancer, uterine cancer, ovarian cancer, pancreatic cancer and kidney cancer.
Dr. Smitha Pabbathi, medical director of the Survivorship Clinic at Moffitt Cancer Center, says this study highlights the important discussion on the impacts of unhealthy weight and second cancer risk for survivors. “We need to counsel survivors on weight maintenance and how weight loss impacts their future cancer risk,” she said.
"We need to counsel survivors on weight maintenance and how weight loss impacts their future cancer risk."- Dr. Smitha Pabbathi, medical director of the Survivorship Clinic
Excess weight can have multiple effects on the body, resulting in metabolic, hormonal and inflammatory balances that can be implicated in increased cancer risk. About 55% of all cancers in women occur in those who are overweight or obese.
Previous studies show women who have gotten weight-loss surgery and those who have lost a large amount of weight do have a lower risk of cancer. Pabbathi says weight loss has the potential to modify future risk of second cancers in survivors.
“I really urge survivors to be open to discuss their concerns with their clinicians in order to create comprehensive strategies for weight reduction and weight maintenance,” she said. “Survivors need to be mindful of the decisions they make with regards to nutrition and activity recommendations so they have more control in reducing this risk.”