Repeat that please.

Top Line: The standard treatment for locally recurrent breast cancer after breast conservation is mastectomy.

The Study: But many ipsilateral breast tumor recurrences are relatively small and may be amenable to repeat breast conservation surgery. This SEER analysis describes outcomes following treatment for small (<2 cm) ipsilateral breast recurrences post-initial lumpectomy. Of 2831 patients fitting the bill from 1999-2015, roughly three-quarters received mastectomy and one-quarter repeat BCS. A multivariate analysis reported worse overall survival among those who received repeat breast-conserving surgery (HR 1.34) as well as worse breast cancer-specific survival (HR 1.45). But this was mainly driven by poor outcomes among those who had repeat breast-conserving surgery without re-irradiation, particularly among those with ER-negative disease. When looking at just the third of patients who also received radiation after repeat breast-conservation, there was no difference in overall or breast cancer-specific survival compared with mastectomy. In this population with relatively small recurrences, chemo didn’t appear to improve survival, possibly because there were too few ER-negative tumors to detect a difference in that high-risk population. At the end of the day, we can’t account for why patients in SEER received the treatment they did nor factors that may influence survival and treatment outcomes.

TBL: In this SEER analysis, salvage repeat breast-conserving surgery alone for small in-breast recurrences was associated with worse survival compared to mastectomy, particularly when radiation was omitted. | Li, Cancer 2022