Immediate Breast Reconstruction Allows for the Timely Initiation of Postmastectomy Radiation Therapy

Abstract

Background: Complications from breast reconstruction may delay postmastectomy radiation therapy and impact breast cancer outcomes. The authors hypothesized that immediate breast reconstruction may be associated with delays in the initiation of radiation, but that this delay would not significantly impact overall patient survival.

Methods: Using the National Cancer Database, the authors identified women with breast cancer who underwent mastectomy and received postmastectomy radiation therapy. Delayed radiation was defined as treatment initiated 6 months or more after surgery in patients who received adjuvant chemotherapy or 12 weeks or more after surgery in patients who received neoadjuvant or no chemotherapy.

Results: Women undergoing breast reconstruction had an increased time to postmastectomy radiation therapy, 154 days versus 132 days (p < 0.001), and were more likely to experience a delay in initiating radiation (OR, 1.25; 95 percent CI, 1.188 to 1.314). Other factors associated with delayed radiation included increased Charlson/Deyo scores, neoadjuvant chemotherapy, nonprivate insurance, and black race. Cox proportional hazards models revealed no evidence of a reduced adjusted overall survival in the immediate breast reconstruction group (hazard ratio, 0.836; 95 percent CI, 0.802 to 0.871; p < 0.001). Restricted cubic spline analysis identified the threshold number of days at which the start of radiation began to impact survival at 169 days (95 percent CI, 160 to 190 days), 75 days (95 percent CI, 42 to 90 days), and 71 days (95 percent CI, 41 to 90 days) in patients undergoing adjuvant, neoadjuvant, and no chemotherapy, respectively.

Conclusion: Immediate breast reconstruction is associated with a modest delay in initiating postmastectomy radiation therapy but does not impact overall survival.

Clinical question/level of evidence: Therapeutic, III.

Figure 1:

Key inclusion and exclusion criteria

Figure 2:

Smoothed restricted cubic spline plot of the adjusted log hazard ratio of death in patients receiving adjuvant (A), neoadjuvant (B), and no chemotherapy (C). The predicted hazards ratios were estimated from a proportional hazards model adjusting for covariates. The light dotted curves represent the 95% confidence intervals about the predicted odds ratio. The black dots correspond to the location of 4 knots used in the model. The dashed vertical line indicates the bootstrapped minimum.