Repeat breast-conserving surgery for ipsilateral breast tumour recurrence: towards a paradigm shift-a narrative review.

Background and objective

Ipsilateral breast tumour recurrence (IBTR) following breast-conserving therapy (BCT) has traditionally been managed with salvage mastectomy because of concerns regarding oncological safety and toxicity associated with repeat breast conservation and re-irradiation. However, accumulating evidence from retrospective series, meta-analyses, prospective cohort studies, and phase II trials has challenged this longstanding paradigm. This narrative review evaluates the evidence supporting repeat breast-conserving treatment (rBCT) as an alternative to salvage mastectomy in selected patients with IBTR.

Methods

A targeted narrative review of published literature was conducted, encompassing meta-analyses, prospective cohort studies, population-based analyses, phase II trials, and relevant international clinical practice guidelines addressing the management of IBTR following BCT. Studies were selected on the basis of clinical relevance, methodological quality, and influence on contemporary practice.

Key content and findings

Two independent meta-analyses, multicentre cohort data from the GEC-ESTRO study, and two landmark phase II trials (NRG Oncology/RTOG 1014 and RE-IORT) collectively demonstrate that rBCT-defined as repeat breast-conserving surgery (rBCS) combined with adjuvant partial breast re-irradiation-achieves local control and overall survival (OS) comparable to salvage mastectomy in carefully selected patients. Re-irradiation is an oncological prerequisite; its omission is associated with a two- to four-fold increase in second local recurrence. Axillary management is evolving towards de-escalation via repeat sentinel lymph node biopsy (rSLNB) and targeted axillary dissection (TAD). Patient selection, tumour biology, and multidisciplinary planning are central to safe implementation.

Conclusions

rBCT represents a clinically valid alternative to salvage mastectomy in carefully selected patients with IBTR, supported by consistent evidence across meta-analyses and prospective trials. Randomised controlled trial data are lacking; ongoing trials (BREAST, REPEAT, and BRASIL) are expected to provide the level I evidence required to inform formal guideline revision. rBCT should be routinely offered and discussed at multidisciplinary team (MDT) level in eligible patients.