top of page

Significant increase in weight gain after breast cancer diagnosis

Weight gain after breast cancer is a greater problem than previously thought, according to the first national survey on weight after breast cancer in Australia, which found close to two-thirds (63.7%) of women reported weight gain at an average of nine kilograms after a breast cancer diagnosis, and overall nearly one-in-five women (17%) added more than 20kgs.

Researchers from NICM Health Research Institute, Western Sydney University and ICON Cancer Centre, Sydney Adventist Hospital, Wahroonga, 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 (BCNA). The study, ‘Weight before and after a diagnosis of breast cancer or ductal carcinoma in situ: a national Australian survey’, was published in BMC Cancer.

The majority of women surveyed (77%) reported gaining weight within the first 12-18 months after diagnosis, which could be the ideal 'window of opportunity' to provide additional support for weight management among women with breast cancer explained Dr Carolyn Ee, lead author, general practitioner and senior research fellow at NICM Health Research Institute, Western Sydney University.

"As well as significant weight gain, we also found high levels of concern about weight among our survey participants. Timing may be the key in helping women to manage weight after a diagnosis of breast cancer," said Ee.

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

The survey also found:

  • The proportion of women who were overweight or had obesity increased from 48% at time of diagnosis to 67% at the time of the survey, with the proportion of women who had obesity almost doubling from 17% to 32%.

  • The majority (69%) of women gained weight in excess of the rates reported in age-matched controls without breast cancer, an additional 2.42 kilograms over five years.

Professor John Boyages AM, co-author and radiation oncologist at Icon Cancer Centre added that all women should be prescribed exercise after being diagnosed with breast cancer, according to the Clinical Oncology Society of Australia (COSA) guidelines.

"As doctors we really need to actively think about weight, nutrition and exercise and advise about possible interventions," said Boyages. "Breast cancer is the most common cancer in women worldwide and in Australia, and weight gain is common after breast cancer treatment. Many patients assume they will lose weight. Weight gain adds to self-esteem problems, increases the risk of heart disease and other cancers and several reports suggest it may affect prognosis and also increases the risk of arm swelling (lymphoedema). Prescribing a healthy lifestyle is just as important as prescribing tablets."

Ee added that 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, she said supervision by an experienced exercise physiologist is invaluable.

The researchers plan to analyse 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.

Further information


bottom of page