Dr Martine Piccart, head of the chemotherapy unit at the Institut Jules Bordet, Brussels, Belgium, is putting proposals for new guidelines to the Breast International Group (BIG) and, if BIG agrees, the issue would be discussed with the North American Breast Intergroup.
She said that breast cancer research had not been well served by trials of adjuvant therapies aimed at preventing cancer returning, which had reported their results early, because this could mean that some questions about long-term efficacy and side effects or untoward effects remained unanswered, and the future of other trials was put at risk.
"Researchers need to achieve a better balance between informing doctors and women quickly about a more effective treatment for breast cancer and the equally important need to collect solid data on the safety of the therapy," she told a discussion group at the 4th European Breast Cancer.
Three recent trials* of aromatase inhibitors (AIs) as adjuvant treatments for breast cancer had all reported results early because they showed significant advantages for AIs over tamoxifen, but Dr Piccart said that an average follow-up time of only 30 months did not enable doctors to weigh up the long-term risks and benefits of the different treatments. If the trials had continued for longer it was possible that the risks of the different treatments would have become clearer (for instance, tamoxifen carries a risk of endometrial cancer and blood clots, whereas AIs carry a risk of osteoporosis and bone fractures), therefore allowing doctors to conduct a useful risk-benefit analysis an integral part of making appropriate decisions about the best treatment for a patient.