One of the biggest ever studies of breast cancer treatment shows that the most effective form of chemotherapy is one that combines an anthracycline and a taxane drug, reducing the risk of breast cancer recurrence and death by a third when compared to taxane regimens without anthracycline. The results are published today in The Lancet.
It has long been known that giving chemotherapy either before or after surgery for breast cancer can substantially reduce the risk of disease recurrence and death, however uncertainties remain about which form of chemotherapy provides the most benefit with the fewest side effects. Anthracycline and taxane drugs work in different ways to inhibit the processes that cancer cells need to be able to divide and spread further. However, anthracycline drugs can increase the long-term risk of cardiovascular disease and acute myeloid leukaemia (AML), and concerns about side-effects have led to an increased use of non-anthracycline chemotherapy in clinical practice.
Researchers from the Early Breast Cancer Trialists’ Collaborative Group, which is led by Oxford Population Health and funded by Cancer Research UK and the Medical Research Council, gathered data on over 100,000 women who participated in 86 randomised clinical trials to assess the benefits and risks of different anthracycline and taxane chemotherapy regimens.
- Chemotherapy regimens that include both an anthracycline and a taxane drug significantly reduced breast cancer recurrence and death compared to taxane regimens without an anthracycline. Across all trials, the risk of recurrence was reduced by an average of 14%.
- Regimens with higher cumulative doses of both anthracycline and taxane were the most effective. In trials that added anthracycline and maintained the same dose of taxane, recurrence was reduced by an average of 42%.
- Benefits were similar for younger and older women, in hormone receptor positive and hormone receptor negative breast cancers, and did not differ by other measured tumour characteristics.
- There was a small increase in the risk of developing acute myeloid leukaemia with anthracyclines, equating to one additional case of AML per 700 women treated.
Dr Jeremy Braybrooke, one of the lead researchers, consultant medical oncologist at University Hospitals Bristol and Weston NHS Trust and senior clinical research fellow at Oxford Population Health, said: ‘For women with operable breast cancer at high enough risk of recurrence to be offered chemotherapy, our study shows that using both an anthracycline and a taxane, achieves the best results. This important finding should be considered in clinical practice as there has been a recent shift towards using shorter chemotherapy regimens that include a taxane but not an anthracycline; our research demonstrates that this is less effective than combination treatment.’
Rosie Bradley, another lead researcher and medical statistician at Oxford Population Health, said: ‘Individual trials have reported increases in heart disease with anthracyclines; however, in this study there was no increase in deaths from cardiovascular causes, or of deaths from other non-breast cancer causes in women who received an anthracycline. There were no consistent differences in short-term toxicity with or without an anthracycline, suggesting that combination therapy is the best option for patients.’