Breast cancer study suggests review of treatment length

A new study published in the New England Journal of Medicine , funded by Cancer Research UK, has found that the risk of breast cancer recurring persists undiminished for at least 20 years after diagnosis, suggesting that hormonal treatments should continue for even longer to reduce the risk of late recurrence. The Early Breast Cancer Trialists' Collaborative Group, an international team of investigators based at the University of Oxford, pooled data from over 60,000 women in 88 clinical trials who had been diagnosed with estrogen receptor positive breast cancer between 1976 and 2011, and prescribed anti-estrogen therapy, such as tamoxifen or an aromatase inhibitor, for 5 years. These women who had no recurrence in the first 5 years, then stopped treatment and their progress was followed for up to 15 further years. Over 11,000 had a recurrence of cancer at a distant site, such as the bone, liver, or lung, with the risk of recurrence during each subsequent year (from years 5-20) remaining about constant. The risk of recurrence was strongly related to the presence and number of involved axillary lymph nodes at diagnosis, as well as the size and pathologic grade of the cancer. The highest risk of recurrence was among women with 4 or more involved axillary nodes, who had a 40% risk of a distant cancer recurrence by year 20 after first diagnosis. Women at the lowest risk, ie those with small, low grade cancers and no spread to the nodes, had a much lower 10% risk of distant spread by year 20.