Radiation for early breast cancer: Is less more?

Extract: Women who present with early breast cancer are initially treated with surgical lumpectomy (removal of the tumor mass) followed by radiation therapy. Breast radiation therapy is well established as the "standard of care" for women with early breast cancer as it has consistently been shown, in randomized clinical trials, to reduce the risk of a relapse in the breast by 60-75%. Excellent control rates and survival following lumpectomy and post-operative breast radiation demonstrate that mastectomies (removal of the entire breast, including the tumor) are normally not necessary for early disease. This is consistent with the consensus of multiple experts in the field following their assessment of multiple clinical trials comparing lumpectomy and mastectomy. The increasing use of mammographic screening for breast cancer has resulted in earlier diagnosis of the disease when the tumors are smaller and so they have not yet spread to the axillary lymph nodes (under the armpits). It has been recognized that systemic adjuvant treatment with the anti-estrogen medication, tamoxifen, that prevents estrogen from stimulating receptive tumor cells, also reduces breast cancer relapse as well as preventing metastatic spread of the disease and improving survival. Survival, however, does not appear to be affected by radiation treatment, and women who are diagnosed with the disease early and who have negative pathological findings in their axillary lymph nodes have a lower risk of breast cancer relapse overall. This has led researchers to look for low-risk subgroups of these women who might reasonably be able to avoid the side-effects and inconvenience of radiation.