Older breast cancer patients are more likely to die of heart disease than from their malignancy a decade after a cancer diagnosis, new research finds.
Researchers from the University of Toronto, Canada who conducted the study said attention to cardiovascular preventive therapy after a diagnosis of breast cancer should be a high priority.
Speaking to the limbic about the findings CEO of Cancer Council Australia Professor Sanchia Aranda said while the issue of increased CVD risk in breast cancer patients was well known, its management was not well structured.
“In paediatrics it’s quite normal to have late effect clinics and for patients to be monitored for cardiovascular and other issues because the development of cardiac disease in young hearts that have been radiated or have had chemotherapy is well understood but in adults those systems aren’t quite as well developed,” she told the limbic.
“It’s difficult – we’re talking about integrating cardiac services into cancer services. It’s expensive to do that because what you would want to do is build clinics around the management of survivors and that’s difficult when there is a big push to move survivors back out into the community.”
Professor Aranda said there has been a lot of work done in clinical practice to avoid cardiovascular toxicity in breast cancer patients, which is improving long-term CV outcomes for patients.
Anthracycline drugs and herceptin, which are cardiotoxic and commonly used in breast cancer patients, are now used more cautiously in women who have a previous history of CV disease.
Radiation therapy and improved shielding techniques that keeps radiation away from the heart and gives less damage to the surround tissues have also improved long term CV outcome in these patients but weight gain still remains a factor that will contribute to increased CVD risk among breast cancer survivors she added.
“We’ve known for some time that breast cancer recurrence is linked to overweight, obesity and lack of exercise and yet we still don’t have systematic post diagnosis rehabilitation of women to help them with this,” she said.
Unlike many cancers where weight loss is a feature of treatment, in women with breast cancer – particularly those who go on to hormonal therapy – weight gain is common.
“The more you gain weight the more likely you are to have cardiac events and so you’re compounding the risk factors.”
The analysis of 21 123 women with early stage breast cancer who had died over 15 years follow-up, found that while breast cancer was the most common cause of death (10 550 deaths [49.9%]), some 3444 deaths [16.3%] were from cardiovascular causes.
Among women 66 years or older, the risks of breast cancer death and cardiovascular death at 10 years were 11.9% and 7.6% respectively.
And for patients with prior CVD, the risk of death from breast cancer and CVD were equivalent for the first 5 years, after which death from cardiovascular causes was more frequent 14.6% for breast cancer compared to 16.9% for CVD.