Breast cancer is the commonest type of cancer among women in most developed countries. For such a common disease, widely practicable treatments that produce only moderate effects on long-term survival, such as increasing the number of women surviving for more than ten years after diagnosis from 50% to 55%, could result in the avoidance of many thousands of deaths each year.
The Early Breast Cancer Trialists' Collaboration Group (EBCTCG) obtains large-scale randomised evidence about long-term and side-effects of breast cancer treatments. It has three objectives, to:
- identify improvements in the treatment of early breast cancer that improve survival
- disseminate the findings that improve patterns of treatment for women worldwide
- influence planning and interpretation of current and future trials
Every five years, CTSU brings together updated data on each woman randomised into all trials of the treatment of operable breast cancer. The EBCTCG process was initiated in 1983 and the first cycle collected data for hormonal and cytotoxic therapy in 1985. The collaboration was extended in the 1990s to all aspects of early breast cancer management and its results informed the year 2000 NIH consenus development conference on the treatment of early breast cancer.
The 2005 report on chemotherapy and endocrine therapy shows the substantial effects on 15-year survival of the chemotherapy regimens (such as about 6 months of FAC or FEC in women aged <70) and hormonal regimens (such as at least 5 years of tamoxifen in women with ER+ disease) that were being tested in the 1980s. The 2005 report on surgery and radiotherapy shows that treatments that substantially improve local control have little effect on breast cancer mortality during the first few years, but definite effects by 15 years.
Further information: http://www.ctsu.ox.ac.uk/~ebctcg/