Relationship of Immediate Breast Reconstruction and the Development of Lymphedema in Breast Cancer Patients with Radiotherapy.

Introduction: Breast cancer-related lymphedema (BCRL) is often challenging to manage, and knowledge of how to prevent it is limited. There are several well-known risk factors, but recent studies have also suggested the potential association of immediate breast reconstruction with lower incidence, albeit with inconclusive results. Thus, we explored the impact of immediate breast reconstruction on lymphedema incidence in breast cancer patients who underwent a mastectomy and adjuvant radiation therapy (RT).

Methods and materials: We retrospectively reviewed 440 breast cancer patients who underwent a mastectomy with adjuvant RT from 2012 to 2020. Of these, 229 underwent immediate breast reconstruction (IR group), and 211 underwent no reconstruction (NR group). BCRL events were defined and graded on a scale of 0 to 3 following the International Society of Lymphology (ISL) staging system. After excluding patients who experienced BCRL before radiotherapy (n=30), with propensity score matching, we utilized log-rank analysis and multivariate Cox regression models to identify associated factors. Then, the clinical course of BCRL was explored with flow diagrams.

Results: After a median follow-up period of 35 months, 116 patients (26%) developed BCRL, with 74% classified as ISL stage 2-3. 2-year actuarial rate of BCRL was 16.3% for the IR group, and 28.9% for the NR group (p=0.020). In a multivariate Cox regression of propensity score-matched (PSM) cohort (n=180), patients were more likely to develop stage ≥2 BCRL if 15 or more axillary lymph nodes were resected (p=0.035), or intensity-modulated radiotherapy (IMRT) was given (p=0.004). However, immediate breast reconstruction was associated with a lower incidence of BCRL (p=0.022). Regarding patients with initial stage 0 or 1 BCRL, the IR group showed a lower rate of progression during follow-up compared with the NR group (33% vs. 60%).

Conclusions: In postmastectomy breast cancer patients, resection of 15 or more axillary lymph nodes, as well as IMRT, were found to be significantly associated with lymphedema occurrence. Notably, immediate breast reconstruction may be associated with a lower incidence of lymphedema.