Scientists at the Kaiser Permanente Division of Research say breast cancer survivors who experience large weight gain have an increased risk of death after diagnosis.
The study found that breast cancer survivors who experienced a large weight gain were 14 percent more likely to experience a recurrence than those whose weight remained stable.
The study also found that women who were naturally leaner and then gained about 10 percent of their weight after cancer had a 25 percent risk of death from the disease.
The study looked at nearly 20,000 women in the After Breast Cancer Pooling Project.
Most women are not gaining a large amount of weight following breast cancer diagnosis, said lead researcher Bette Caan, DrPH, a senior research scientist at the Kaiser Permanente Division of Research. However, our analysis showed an association with poorer outcomes overall for those who do. She explained that moderate weight gain did not affect breast cancer outcomes.
Women tend to worry about gaining weight after a breast cancer diagnosis, said Caan. But its actually only the larger weight gains that increase the risk of poor outcomes.




