Postmastectomy radiotherapy in patients with breast cancer - author's reply. The Lancet, Nov 2014, Vol. 384(9957), p.1846-47
Early Breast Cancer Trialists' Collaborative Group
http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(14)62240-6/fulltext?rss=yes#bib1
Our meta-analysis of individual patient data from trials in women given mastectomy and axillary clearance to at least level ll showed that radiotherapy reduced mortality from breast cancer by 20% in women with one to three positive lymph nodes (rate ratio [RR], irradiated vs not, 0·80, 95% CI 0·67—0·95; 2p=0·01) and by 13% in women with at least four positive lymph nodes (RR 0·87, 95% CI 0·77—0·99; 2p=0·04). Little reason of how radiotherapy works exists to think that this treatment for breast cancer has any appreciable abscopal effect and so, as Ismail Jatoi suggests, these results showed that a proportion of the deaths avoided by radiotherapy would have arisen from cells localised within the areas targeted by radiotherapy (ie, the chest wall and, for most trials, the regional lymph nodes).
