Post-Mastectomy Radiotherapy After Neoadjuvant Chemotherapy in Breast Cancer: A Pooled Retrospective Analysis of Three Prospective Randomized Trials.

Abstract

BACKGROUND:

The impact of locoregional radiotherapy (RT) after neoadjuvant chemotherapy (NACT) and mastectomy in breast cancer patients is currently unclear. Several publications have suggested that patients with a favorable response to NACT might not benefit from RT after mastectomy.

METHODS:

A retrospective analysis of three prospective randomized NACT trials was performed. Information on the use of RT was available for 817 breast cancer patients with non-inflammatory breast cancer who underwent mastectomy after NACT within the GeparTrio, GeparQuattro, and GeparQuinto-trials. RT was administered to 676 of these patients (82.7%).

RESULTS:

The 5-year cumulative incidence of locoregional recurrence (LRR) was 15.2% (95% confidence interval [CI] 9.0-22.8%) in patients treated without RT and 11.3% in patients treated with RT (95% CI 8.7-14.3%). In the multivariate analysis, RT was associated with a lower risk of LRR (hazard ratio 0.51, 95% CI 0.27-1.0; p = 0.05). This effect was shown especially in patients with cT3/4 tumors, as well as in patients who were cN+ before neoadjuvant therapy, including those who converted to ypN0 after neoadjuvant therapy. In the bivariate analysis, disease-free survival was significantly worse in patients who received RT, however this was not confirmed in the multivariate analysis.

CONCLUSIONS:

Our results suggest that RT reduces the LRR rates in breast cancer patients who receive a mastectomy after NACT without an improvement in DFS. Prospective randomized controlled trials such as the National Surgical Adjuvant Breast and Bowel Project B-51/RTOG 1304 trial will analyze whether RT has any benefit in patients who have a favorable response after NACT.

• Authors: David Krug, Bianca Lederer, Fenja Seither, Valentina Nekljudova, Beyhan Ataseven, Jens-Uwe Blohmer, Serban Dan Costa, Carsten Denkert, Nina Ditsch, Bernd Gerber, Claus Hanusch, Joerg Heil, Jörn Hilfrich, Jens B Huober, Christian Jackisch, Sherko Kümmel, Stefan Paepke, Christian Schem, Andreas Schneeweiss, Michael Untch, Jürgen Debus, Gunter von Minckwitz, Thorsten Kühn, Sibylle Loibl
• Journal: Annals of surgical oncology (Ann Surg Oncol) Vol. 26 Issue 12 Pg. 3892-3901 (Nov 2019) ISSN: 1534-4681 [Electronic] United States
• PMID: 31350646 (Publication Type: Journal Article, Randomized Controlled Trial)

Topics

• Adult
• Aged
• Antineoplastic Combined Chemotherapy Protocols (therapeutic use)
• Breast Neoplasms (mortality, pathology, therapy)
• Carcinoma, Ductal, Breast (mortality, pathology, therapy)
• Carcinoma, Lobular (mortality, pathology, therapy)
• Combined Modality Therapy
• Female
• Follow-Up Studies
• Germany (epidemiology)
• Humans
• Incidence
• Mastectomy (mortality)
• Middle Aged
• Neoadjuvant Therapy (mortality)
• Neoplasm Recurrence, Local (epidemiology, mortality, pathology, therapy)
• Prognosis
• Prospective Studies
• Radiotherapy (mortality)
• Retrospective Studies
• Survival Rate
• Young Adult