© 2007 European Society for Medical Oncology
breast cancer |
Is avoiding post-mastectomy radiotherapy justified for patients with four or more involved axillary nodes and endocrine-responsive tumours? Lessons from a series in a single institution
1 Division of Breast Surgery
2 Division of Epidemiology and Biostatistics
3 Department of Medical Oncology
4 Scientific Director, European Institute of Oncology, Milan, Italy
* Correspondence to: Dr O. Gentilini, Division of Senology, European Institute of Oncology, Via Ripamonti 435, 20141, Milano, Italy. Tel: +39-02-57489376; Fax: +39-02-57489780; E-mail: oreste.gentilini{at}ieo.it
Background: Current guidelines for post-mastectomy radiotherapy (PMRT) derive largely from extrapolating information from multicentre trials. The aim of this study was to describe outcomes of patients who underwent mastectomy without radiotherapy in a single institution.
Patients and methods: 650 patients had total mastectomy and axillary dissection without PMRT between 1997 and 2001. Median follow-up was 65 months.
Results: 5-year cumulative incidence of loco-regional recurrence (LRR) was 6.8% (3.0, 8.1, 9.9% in node negative, 1–3, 
4 positive nodes, respectively). At the multivariate analysis, positive lymph nodes and endocrine non-responsive tumours were found to shorten LRR disease-free survival. In patients with positive hormone receptors, 5-year cumulative incidence of LRR disease-free survival were 2.3%, 7.6% and 7.6% for node negative, 1–3 and 4 positive lymph nodes, respectively. The same figures were 5.9%, 10.3% and 20.0% in patients with endocrine non-responsive tumours.
Conclusions: patients with endocrine-responsive tumours treated by mastectomy and complete (level III) axillary dissection have a low risk of LRR even if four or more positive lymph nodes are involved, thus giving rise to doubts on the use of PMRT in this subset of patients. On the other hand, PMRT might play a role for patients with negative hormone receptors and four or more positive nodes.
Key words: mastectomy, radiotherapy, recurrence, breast cancer, hormone receptor
All listed authors directly contributed to the manuscript: O.G. conception of the study, interpretation of data and drafting the manuscript; E.B., N.R., S.G. analysis of data; M.I., G.G., A.L., P.V., V.G. critical revision of the manuscript; L.S., N.P., R.C.S. acquisition of data; A.G. and U.V. interpretation of data, drafting the manuscript and final approval. Received for publication March 13, 2007. Revision received April 4, 2007. Accepted for publication April 5, 2007.