Hypofractionated irradiation of infra-supraclavicular lymph nodes after axillary dissection in patients with breast cancer post-conservative surgery: impact on late toxicity.

Background: The aim of the present work was to analyse the impact of mild hypofractionated radiotherapy (RT) of infra-supraclavicular lymph nodes after axillary dissection on late toxicity.

Methods: From 2007 to 2012, 100 females affected by breast cancer (pT1- T4, pN1-3, pMx) were treated with conservative surgery, Axillary Node Dissection (AND) and loco-regional radiotherapy (whole breast plus infra-supraclavicular fossa). Axillary lymph nodes metastases were confirmed in all women. The median age at diagnosis was 60 years (range 34-83). Tumors were classified according to molecular characteristics: luminal-A 59 pts (59%), luminal-B 24 pts (24%), basal-like 10 pts (10%), Her-2 like 7 pts (7%). 82 pts (82%) received hormonal therapy, 9 pts (9%) neo-adjuvant chemotherapy, 81pts (81%) adjuvant chemotherapy. All patients received a mild hypofractionated RT: 46 Gy in 20 fractions 4 times a week to whole breast and infra-supraclavicular fossa plus an additional weekly dose of 1,2 Gy to the lumpectomy area. The disease control and treatment related toxicity were analysed in follow-up visits. The extent of lymphedema was analysed by experts in Oncological Rehabilitation.

Results: Within a median follow-up of 50 months (range 19-82), 6 (6%) pts died, 1 pt (1%) had local progression disease, 2 pts (2%) developed distant metastasis and 1 subject (1%) presented both. In all patients the acute toxicity was mainly represented by erythema and patchy moist desquamation. At the end of radiotherapy 27 pts (27%) presented lymphedema, but only 10 cases (10%) seemed to be correlated to radiotherapy. None of the patients showed a severe damage to the brachial plexus, and the described cases of paresthesias could not definitely be attributed to RT. We did not observe symptomatic pneumonitis.

Conclusions: Irradiation of infra-supraclavicular nodes with a mild hypofractionated schedule can be a safe and effective treatment without evidence of a significant increase of lymphedema appearance radiotherapy related.