Breast-conserving surgery with or without radiotherapy in women with ductal carcinoma in situ: a meta-analysis of randomized trials

<p>Abstract</p> <p>Background</p> <p>To investigate whether Radiation therapy (RT) should follow breast conserving surgery in women with ductal carcinoma in situ from breast cancer (DCIS) with objective of decreased mortality, invasive or non invasive recurrence, distant metastases and contralateral breast cancer rates. We have done a meta-analysis of these results to give a more balanced view of the total evidence and to increase statistical precision.</p> <p>Methods</p> <p>A meta-analysis of randomized controlled trials (RCT) was performed comparing RT treatment for DCIS of breast cancer to observation. The MEDLINE, EMBASE, CANCERLIT, Cochrane Library databases, Trial registers, bibliographic databases, and recent issues of relevant journals were searched. Relevant reports were reviewed by two reviewers independently and the references from these reports were searched for additional trials, using guidelines set by QUOROM statement criteria.</p> <p>Results</p> <p>The reviewers identified four large RCTs, yielding 3665 patients. Pooled results from this four randomized trials of adjuvant radiotherapy showed a significant reduction of invasive and DCIS ipsilateral breast cancer with odds ratio (OR) of 0.40 (95% CI 0.33 – 0.60, p < 0.00001) and 0.40 (95% CI 0.31 – 0.53, p < 0.00001), respectively. There was not difference in distant metastases (OR = 1.04, 95% CI 0.57–1.91, p = 0.38) and death rates (OR = 1.08, 95%CI 0.65 – 1.78, p = 0.45) between the two arms. There was more contralateral breast cancer after adjuvant RT (66/1711 = 3.85%) versus observation (49/1954 = 2.5%). The likelihood of contralateral breast cancer was 1.53-fold higher (95% CI 1.05 – 2.24, p = 0.03) in radiotherapy arms.</p> <p>Conclusion</p> <p>The conclusion from our meta-analysis is that the addition of radiation therapy to lumpectomy results in an approximately 60% reduction in breast cancer recurrence, no benefit for survival or distant metastases compared to excision alone. Patients with high-grade DCIS lesions and positive margins benefited most from the addition of radiation therapy. It is not yet clear which patients can be successfully treated with lumpectomy alone; until further prospective studies answer this question, radiation should be recommended after lumpectomy for all patients without contraindications.</p

The role of radiotherapy in the conservative treatment of ductal carcinoma in situ of the breast.

Breast-conserving surgery (BCS) followed by radiotherapy (RT) has become the standard of care for the treatment of early-stage (St. I-II) invasive breast carcinoma. However, controversy exists regarding the value of RT in the conservative treatment of ductal carcinoma in situ (DCIS). In this article we review the role of RT in the management of DCIS. Retrospective and prospective trials and meta-analyses published between 1975 and 2007 in the MEDLINE database, and recent issues of relevant journals/handbooks relating to DCIS, BCS and RT were searched for. In retrospective series (10,194 patients) the 10-year rate of local recurrence (LR) with and without RT was reported in the range of 9-28% and 22-54%, respectively. In four large randomised controlled trials (NSABP-B-17, EORTC-10853, UKCCCR, SweDCIS; 4,568 patients) 50 Gy whole-breast RT significantly decreased the 5-year LR rate from 16-22% (annual LR rate: 2.6-5.0%) to 7-10% (annual LR rate: 1.3-1.9%). In a recent meta-analysis of randomised trials the addition of RT to BCS resulted in a 60% risk reduction of both invasive and in situ recurrences. In a multicentre retrospective study, an additional dose of 10 Gy to the tumour bed yielded a further 55% risk reduction compared to RT without boost. To date, no subgroups have been reliably identified that do not benefit from RT after BCS. In the NSABP-B-24 trial, the addition of tamoxifen (TAM) to RT reduced ipsilateral (11.1% vs. 7.7%) and contralateral (4.9% vs. 2.3%) breast events significantly. In contrast, in the UKCCCR study, TAM produced no significant reduction in all breast events. Based on available evidence obtained from retrospective and prospective trials, all patients with DCIS have potential benefit from RT after BCS. Further prospective studies are warranted to identify subgroups of low-risk patients with DCIS for whom RT can be safely omitted. Until long-term results of ongoing studies on outcomes of patients treated with BCS alone (with or without TAM or aromatase inhibitors) are available, RT should be routinely recommended after BCS for all patients except those with contraindication