# Postoperative complications after salvage mastectomy and repeat breast-conserving surgery in patients with IBTR after previous breast-conserving surgery: a multicenter, retrospective cohort study

## TL;DR

This study compares complication rates after salvage mastectomy or repeat breast-conserving surgery in patients with breast cancer recurrence, finding higher risks with mastectomy, especially in those with higher BMI.

## Contribution

The study provides empirical evidence on complication rates and risk factors for salvage mastectomy versus repeat breast-conserving surgery in IBTR patients.

## Key findings

- Salvage mastectomy had a 45.2% short-term complication rate, compared to 16.4% for repeat BCS.
- Higher BMI significantly increased the risk of short-term complications after salvage mastectomy.
- Adjuvant radiotherapy after salvage mastectomy was linked to long-term complications.

## Abstract

In patients with ipsilateral breast tumor recurrence (IBTR) previously treated with breast-conserving surgery (BCS) followed by radiotherapy, salvage mastectomy (SM) is still considered standard of care. Currently, there is little evidence available about complication rates of repeat BCS or salvage mastectomy in patients with IBTR and possible differences.

The primary aim was to report postoperative complication rates after IBTR treatment with salvage mastectomy or repeat BCS after previous BCS (± radiotherapy). Secondary, risk factors associated with complications were examined.

Complication rates were reported using descriptive statistics. Complications were classified between short-term (less than 3 months after surgery) and long-term (more than 3 months after surgery). Logistic regression was used to evaluate possible risk factors after salvage mastectomy to report an odds ratio (OR) with a 95% confidence interval (CI).

A total of 549 cases with IBTR after primary BCS were included. Short-term complications occurred in 200 (45.2%) of 442 patients treated with salvage mastectomy and in 9 (16.4%) of 55 patients treated with repeat BCS. Seroma and surgical site infection (SSI) were most common in salvage mastectomy (31.7% and 10.9%, respectively). Long-term complications were reported in 16.7% treated with salvage mastectomy and in 14.5% with repeat BCS. The risk of short-term postoperative complications after salvage mastectomy increased significantly with higher BMI. The regression analysis showed that adjuvant radiotherapy after IBTR surgery was associated with long-term postoperative complications.

Salvage mastectomy in case of IBTR after primary BCS is associated with high short-term complication rates, especially seroma. The risk of short-term complications after salvage mastectomy increased with increasing BMI, while adjuvant radiotherapy after salvage mastectomy is associated with long-term complications.

The online version contains supplementary material available at 10.1007/s10549-026-07908-6.