Study shows significant increase in weight after breast cancer, calls for prevention

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Weight gain after breast cancer is a greater problem than previously thought, according to new research published in the journal BMC Cancer.

The study, highlighting a national survey on weight after breast cancer in Australia, found that 63.7 percent of women reported weight gain at an average of about 20 pounds after a breast cancer diagnosis, and overall 17 percent of women added more than 45 pounds, the study said.

Researchers from NICM Health Research Institute in Westmead, Australia surveyed 309 women with breast cancer living in Australia using an anonymous, self-administered, online, cross-sectional survey between November 2017 and January 2018. The national sample consisted mainly of members from Breast Cancer Network Australia/

The majority of women surveyed, 77 percent, reported gaining weight within the first 12 to 18 months after diagnosis, which could be the ideal window of opportunity to provide additional support for weight management among women with breast cancer, the researchers said.

The survey also found that the proportion of women who were overweight or obese increased from 48 percent at time of diagnosis to 67 percent at the time of the survey, with the proportion of women who were obese almost doubling from 17 percent to 32 percent. The majority, 69 percent, of women gained weight in excess of the rates reported in age-matched controls without breast cancer, the study said.

All women should be prescribed exercise after being diagnosed with breast cancer, according to the Clinical Oncology Society of Australia (COSA) guidelines, the researchers said.  After diagnosis of breast cancer, many women experience fatigue, which can be a barrier to staying active, and studies show exercise is an effective treatment for fatigue. However, for this to be feasible and sustainable, supervision by an experienced exercise physiologist is invaluable, according to Carolyn Ee, PhD, lead author of the study.

The researchers will next analyze the survey data to investigate reasons why women are gaining weight after breast cancer, with several risk factors reported in other studies, including the type of treatment that women receive, and whether or not they were menopausal before diagnosis and treatment, Ee said.

"Cancer services and general practitioners play an important role in having early conversations with women,” she said in a statement, “and referring them to a team of qualified healthcare professionals such as dieticians and exercise physiologists with experience in cancer.”