RESPONSE: Re: Breast-Conserving Surgery With or Without Radiotherapy: Pooled-Analysis for Risks of Ipsilateral Breast Tumor Recurrence and Mortality

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Kunkler et al. address an important issue: whether or not to continue randomized trials of postoperative radiotherapy after breast-conserving surgery in selected patient subgroups such as those in the Scottish Post-operative Radiotherapy In Minimum-risk Elderly II (PRIME II) and the Italian RT 55-75 trials ( 1 ). We welcome the opportunity to analyze the additional data that the PRIME II and the RT 55-75 trials will provide because we think these data will help patients make the best treatment choices.

In 2003, the updated report ( 2 ) from the 2001 Cancer and Leukemia Group B (CALGB) 9343 trial ( 3 ) provided insight into several age-related issues. One issue is that the extreme difficulty in following up older patients may have led earlier studies to mistakenly conclude a lower risk of recurrence. The updated report revealed substantially improved registration of deaths and recurrences—55 deaths were reported (30 deaths with no radiotherapy, 25 deaths with radiotherapy, and a statistically nonsignificant 19% excess relative risk of mortality from omitting radiotherapy). The updated report also showed statistically significantly poorer in-breast and poorer locoregional recurrence-free survivals in the absence of radiotherapy ( 2 ).