Clinical Outcomes of Implant-Based Breast Reconstruction in Patients with Prior Radiation Therapy: Does Timing of Prior Radiation Matter?

Objective:

Although radiation therapy(XRT) is a known predictor of complications in implant-based breast reconstruction, implant-based options remain important due to patient preference and suboptimal autologous candidates. Furthermore, indications for XRT continue to expand. Currently, there is limited data on outcomes for implant-based reconstruction in patients with remote history of XRT due to prior failed breast-conservation therapy. Little is known about how overall timing of prior XRT may affect complication rates.

Methods:

A retrospective review was conducted on all patients who underwent expander-implant-based breast reconstruction at our institution between November 2010 and June 2016. Demographics, operative details, and history/timing of XRT were recorded. Patients with non-breast-related XRT and reconstructions involving autologous flaps were excluded. For bilateral breast reconstructions, each breast was recorded separately. Outcomes including infection, wound dehiscence, skin necrosis, capsular contracture, and reoperation were documented. Baseline characteristics and complication rates were compared for no-XRT, prior-XRT(XRT before mastectomy), and adjuvant XRT(adj-XRT) groups using Chi-square and Fisher’s exact tests. Logistic regression and multi-way ANOVA were performed for multivariate analyses.

Results:

919 cases, representing 537 unique patients, were identified in total. After applying the exclusion criteria, 896 cases of implant-based breast reconstruction(603 patients) were analyzed: 718 cases no-XRT, 146 adj-XRT, and 32 prior-XRT. The three groups were similar for most demographic and peri-operative variables; however, prior-XRT patients were significantly older (59 yrs vs 49 yrs no-XRT and 47 yrs adj-XRT, p < 0.001 for both) and had smaller average final tissue-expander fill volume (333 cc vs 449 cc no-XRT and 440 cc adj-XRT, p < 0.001). Prior-XRT patients completed XRT at an average of 10.9 years prior to reconstruction. Average postoperative follow-up was 3.7 years. Compared to no-XRT, patients who received any XRT had higher rates of overall acute complications requiring surgical intervention (7.7% no-XRT vs 15% XRT, p< 0.005), including specifically for infection (3.1% no-XRT vs 6.7% XRT, p<0.05). XRT patients also had higher rates of capsular contracture (16.9% XRT vs 3.6% no-XRT, p< 0.001). Within the XRT group, prior-XRT was associated with higher rates of takeback (28% prior-XRT vs 12% adj-XRT, p<0.005), particularly for infection and skin necrosis. Multivariate regression analysis adjusting for potential confounders among groups’ independent demographic and peri-operative factors revealed that while XRT overall was associated with higher rate of complications, timing of XRT was not itself an independent predictor in the development of these complications.

Conclusion:

Radiation therapy results in higher overall complications in implant-based reconstruction, including higher rate of takebacks for complications such as infection and skin necrosis. The damaging effects of XRT appear long-lasting, as patients with history of XRT more than 10 years prior to reconstruction had similar complication rates compared to those with more recent XRT and those undergoing adjuvant XRT. Additional investigations will be needed to further characterize specific effects of XRT timing on reconstruction outcomes, but this study represents a rare longitudinal analysis of these variables and their ability to predict surgical outcomes, which are crucial for patient counseling and selection of reconstructive options.