Breast cancer treatment link to chronic disease

Women who have undergone hormonal therapy for breast cancer are at increased risk of developing chronic conditions later in life, according to new research.

Researchers from the University of South Australia and Flinders University found that rates of cardiovascular disease, depression, osteoporosis, diabetes and gastric disorders were higher among breast cancer survivors who had received hormonal cancer treatment than among those without breast cancer.

However, the researchers say an increased focus on healthy diets and regular exercise can play a crucial role in preventing chronic conditions post-cancer.

The study was published this week in the Medical Journal of Australia.

Hormonal therapy, also known as endocrine therapy, is currently used to reduce the risk of cancer recurrence for 70 per cent of breast cancers in Australia. It is typically administered after surgery or a course of chemotherapy or radiation.

The study compared the health of two groups of women over a 10-year period, the first group comprising women who were receiving hormonal therapy for breast cancer and the second group comprising women of a similar age who did not have breast cancer.

The emergence of chronic disease and the frequency with which it developed was mapped in both groups.

Flinders University Professor and co-researcher Bogda Koczwara said the study found that chronic illnesses developed more frequently in women with breast cancer than in those without breast cancer and that the risk for developing chronic illnesses among women with breast cancer was greatest during their first year of hormonal therapy.

"Some of this risk may be attributable to hormonal therapy, and some of it may be the effect of the cancer itself or its earlier treatment," Professor Koczwara said.

"Hormonal therapy is still a very important treatment option for women with hormone responsive cancer, but we need to manage its subsequent impact on long-term health in a more informed and impactful way.

"Knowing that hormonal therapy may predispose women to developing chronic illnesses gives us the chance to develop effective, long-term models of care for these patients.

"Developing the strategies and tools to manage co-existing chronic conditions after breast cancer should now be an essential part of every patient's overall treatment plan."

The study was the first of its kind in Australia to comprehensively examine the relationship between breast cancer treatment and the development of successive chronic disease using the analysis of prescribing patterns.

Co-researcher Dr. Agnes Vitry from the University of South Australia said maintaining a healthy diet and active lifestyle during treatment and after remission was crucial.

She said regular exercise in particular was a key factor in reducing the likelihood of developing a range of chronic conditions including diabetes, osteoporosis, cardiovascular disease and depression.

"The story doesn't end with the end of treatment for cancer survivors – most of them have long-term effects and this needs to be taken into account in the way that we care for them," Dr. Vitry said.

"It's very important in the long term to eat a healthy diet and do as much exercise as you can as it's very good to counteract the effects from the toxic drugs you are given to cure the cancer.

"Too often people think 'I should stay in bed and rest' but it is exactly the opposite because cardiovascular disease is a big killer for women who have had breast cancer."