Single Institution Clinical Outcomes for Locally Recurrent Breast Cancer Patients Treated with a Second Breast Conserving Surgery and Intraoperative Radiotherapy

Abstract

For early stage breast cancer patients who have received whole breast radiotherapy as part of their initial treatment, and then present with ipsilateral breast recurrence, a standard treatment option is mastectomy. Recent reports indicate that well-selected patients can be treated with a second breast conserving surgery and partial breast reirradiation with good toxicity and clinical outcomes. We report the patient characteristics and clinical outcomes for patients treated with a second breast conserving treatment with intraoperative radiotherapy (IORT) at our institution. Materials/Methods: Records were retrospectively reviewed of 61 locally recurrent breast cancer patients treated with IORT in the setting of a second breast conserving treatment from 2012-2017. All patients had refused mastectomy and elected for a second breast conserving treatment. Results: The median age at time of IORT was 71 years old (range: 44 e 85). The median time interval between the initial surgery and the second surgery was 15.8 years (2.3 e 30.3). The median tumor size was 0.7 cm (0.05 e 2.7). The histologies of the recurrent tumors were 55.7% invasive ductal carcinoma, 18.0% invasive lobular carcinoma, and 24.6% ductal carcinoma in situ. Regarding receptor status, 55/61 (90.2%) were ER or PR positive, 8/61 (13.1%) were Her2+, and 2/61 (3.3%) were triple-negative. Regarding histologic grade, 4/57 (7.0%) were low-grade, 29/57 (50.9%) were intermediate-grade, and 24/57 (42.1%) were high-grade. There was node positivity in 5/61 (8.2%) patients. At a median follow-up time of 10.3 months (0.0 e 51.7), there were 2 distant recurrences (2/61 Z 3.3%) and 3 local recurrences (3/61 Z 4.9%). The two patients with distant recurrence were both diagnosed with bone metastases within a few months of the second breast conserving treatment; both were node-positive. The three local recurrences occurred at 24, 16, and 21 months after the second breast conserving treatment. Two underwent subsequent bilateral mastectomies and the third underwent a third lumpectomy; all three are currently without evidence of disease. Conclusion: For carefully selected patients with locally recurrent breast cancer, IORTas part of a second breast conserving treatment appeared to show acceptable short term clinical outcomes. Nodal status may be a risk factor for a second recurrence. Longer follow-up and proper risk stratification will be necessary to demonstrate efficacy as an alternative treatment option.