ORLANDO, Fla. Breast cancer survivors who experience extreme weight gain have an increased risk of death after breast cancer diagnosis. Moderate weight gain did not affect breast cancer outcomes. These study results were presented at the AACR 102nd Annual Meeting 2011, held here April 2-6.
The investigation, which looked at the association of post-diagnosis weight gain and breast cancer outcomes, was conducted by researchers at Kaiser Permanente in Northern California. Data for the study came from the After Breast Cancer (ABC) Pooling Project, which includes 18,336 breast cancer survivors from four prospective cohorts three in the United States and one in Shanghai, China.
Participants were diagnosed with invasive primary breast cancer between 1976 and 2006; their ages ranged from 20 to 83 years. Weight and body mass index (BMI) were assessed 18 to 48 months after diagnosis and were compared with each woman's pre-diagnosis weight.
"Most women are not gaining a large amount of weight following breast cancer diagnosis," said lead researcher Bette Caan, Dr.P.H., senior research scientist at the Kaiser Permanente Division of Research. "But our analysis of the pooled data showed an association with poorer outcomes overall for those who do."
While extreme weight gain occurred in 16 percent of the women overall, 19.4 percent of women with a BMI lower than 25 before diagnosis fell into this category. Breast cancer survivors who gained the most (10 percent or more over their pre-diagnosis weight was considered extreme) were 14 percent more likely to experience a cancer recurrence compared with women whose weight remained stable (within 5 percent of pre-diagnosis weight) following diagnosis.
"Women tend to worry about gaining weight after a breast cancer diagnosis," said Caan. "But it's actually only the larger weight gains that increase the risk of poor outcomes."
Moderate weight gain (a 5 to 10 percent increase
|Contact: Jeremy Moore|
American Association for Cancer Research