Individualizing Adjuvant Radiotherapy in Patients With Breast Cancer: Let's Not Get Ahead of Ourselves
Authors: Antonin Levy, Sofia Rivera, Eleonor Rivin del Campo, Cyrus Chargari, Rodrigo Arriagada
Journal: Journal of Clinical Oncology (2014)

In a recent analysis, Wickberg et al 1 confirmed the long-term benefit of postoperative radiotherapy in a study of 381 women with pT1N0 breast cancer treated between 1981 and 1988.This trial was included in the Early Breast Cancer Trialists' Collaborative Group (EBCTCG) overview 2 and represents about 3.5% of the worldwide randomized experience.The latter study identified four independent prognostic factors of recurrence: age, histological grade, surgical resection extent, and estrogen receptor status/tamoxifen treatment.Curiously, Wickberg et al provide results in terms of all recurrences adopting a similar definition of that used in the overview.However, in the worldwide studies this definition was related to the fact that several trials only registered the first recurrence and not the subsequent ones.This is not the case of the O ¨rebro-Uppsala trial, as these had been previously reported. 3Although the specific results on local recurrences are mentioned, they are not described in detail, and that obscures the message regarding early and late recurrences.Indeed, a different model may have been used to analyze the Swedish trial, such as competing events approaches, and it would definitely be useful if Wickberg et al may provide these results which were forcedly hidden in the overview.This information is clearly relevant as local recurrences may be salvaged in contrast with distant events.In the Gustave Roussy (GR) trial, 4 comparing a breastconserving approach with total mastectomy for patients with pT1 tumors, with a mean follow-up of 22 years, contrarily to the current report, we found that breast recurrences continued to appear in the lumpectomy group beyond 10 years of follow-up.This could be partially explained by the fact that the local surgical procedure was not a sectorial surgery, but a lumpectomy with a minimal 2-cm histological free margin.Another explanation is that patients of this trial were annually followed at GR, and not in peripheral, nonspecialized clinics, for a period beyond 20 years.The late local recurrences appeared despite the use of a 15 Gy boost which may decrease this risk by two-fold 5 ; this additional treatment was not used in the Swedish trial.It is also of note that the French and Swedish trials did not use adjuvant tamoxifen, as they were performed in the 1970s and 1980s, respectively.In describing a subgroup of patients who could avoid adjuvant radiotherapy, the Cancer and Leukemia Group B (CALGB) 9343 had recently revived the debate on therapeutic de-escalation. 6 In this study, including 636 patients aged 70 years or more, all receiving tamoxifen, radiotherapy significantly decreased locoregional recurrences from 10% to 2% (P ϭ .001) at 10 years, but there were no differences in survival.Again, the latter trial (also included in the overview) did not have enough statistical power to test survival differences, which was most certainly the case with the EBCTCG overview