Optimal timing of postmastectomy radiotherapy in two-stage prosthetic breast reconstruction: An updated meta-analysis.

[BACKGROUND] There is no consensus on the timing of postmastectomy radiotherapy (PMRT) in relation to the exchange procedure in breast cancer patients undergoing the immediate two-stage prosthetic breast reconstruction. This meta-analysis investigated the reconstruction failure, complications, and cosmesis between PMRT to the tissue expander (TE) and PMRT to the permanent implant (PI).

[METHODS] A literature search was conducted in PubMed and Embase databases until February 2022. Studies presenting at least one aspect relating to reconstruction failure, complications, and cosmesis between two cohorts were included. Newcastle-Ottawa Scale (NOS) was used to assess the risk of bias in included studies.

[RESULTS] Eleven studies presenting 1447 patients were enrolled. Three studies were prospective controlled research. The risk for implant loss was higher in PMRT to TE cohort (RR 1.75; 95% CI, 1.03 to 2.98; p = 0.04); meanwhile, the PMRT to TE cohort had a significantly lower risk of capsular contracture (RR 0.47; 95% CI, 0.29 to 0.78; p = 0.003). However, the synthesized result should be interpreted sensibly due to heterogeneity in statistical methods and definitions.

[CONCLUSION] Delivering PMRT to PI may reduce the risk of implant loss, while delivering PMRT to TE can reduce the risk of severe capsular contracture. More high-quality studies are warranted for the refinement of clinical practice.