Temporal Trends in Postmastectomy Radiation Therapy and Breast Reconstruction Associated With Changes in National Comprehensive Cancer Network Guidelines

Abstract

Importance Evolving data on the effectiveness of post-mastectomy radiation therapy (PMRT) have led to changes in NCCN recommendations, counseling providers to “strongly consider” PMRT for breast cancer patients with tumors ≤5cm and 1-3 positive nodes; however, anticipated PMRT may lead to delay or omission of reconstruction which can have cosmetic, quality of life, and complication implications for patients. Objective To determine whether revised guidelines have increased PMRT and impacted receipt of breast reconstruction. We hypothesized that: 1) PMRT would increase for women affected by the revised guidelines while remaining stable in other cohorts, and 2) that these women would have decreased receipt of breast reconstruction while reconstruction increased in other groups. Design A retrospective, population-based cohort study Setting Surveillance, Epidemiology, and End Results (SEER) data from 2000 – 2011. Participants Women with stage I-III breast cancer undergoing mastectomy were identified. Our analytic sample (n=62,442) was divided into cohorts based on current NCCN radiation recommendations: “Radiation Recommended” (tumors >5 cm or ≥4 positive lymph nodes), “Strongly Consider Radiation” (tumor ≤5cm, 1-3 positive nodes), and “Radiation Not Recommended” (tumors ≤5cm, no positive nodes). Main Outcome Measure(s) We used joinpoint regression analysis to evaluate temporal trends in our outcomes of interest: receipt of PMRT and receipt of breast reconstruction. Results Rates of PMRT were unchanged in the “Radiation Recommended” and “Radiation Not Recommended” cohorts over the study period. In contrast, receipt of PMRT for the “Strongly Consider Radiation” cohort was unchanged until 2007, then significantly increased (APC 9.0%, p=0.013). Breast reconstruction increased across all cohorts. Despite increasing receipt of PMRT, the “Strongly Consider Radiation” cohort maintained a consistent increase in reconstruction (APC 7.5%) throughout the study period. This is similar to the increase in reconstruction observed for the “Radiation Recommended” (10.7%) and “Radiation Not Recommended (8.4%) cohorts. Conclusions and Relevance NCCN guideline changes have increased PMRT receipt for patients with tumors ≤5cm and 1-3 positive nodes without an associated decrease in receipt of reconstruction. This may represent increasing provider comfort with the prospect of irradiating a new breast reconstruction, and may have significant cosmetic and quality of life implications for patients.

Current Trends in Postmastectomy Breast Reconstruction

“…Traditional indications of radiotherapy included tumor size of 5 cm or larger, involvement of four or more lymph nodes, and extension to skin or muscle; however, increasing numbers of patients are offered irradiation by many institutions including those with fewer lymph nodes and smaller tumor size [60–62]. It is not uncommon for a woman with a single involved lymph node to receive PMRT in our center.…”

“…Studies report improved HR-QoL among radiated patients who undergoing immediate compared with delayed breast reconstruction [53, 54, 63–66]. As such, plastic surgeons must increasingly balance their reconstruction planning along with the anticipated need for adjuvant treatments [60, 67, 68]. That said, a well-defined algorithm for breast reconstruction in the setting of PMRT is lacking.…”

Postmastectomy Radiation Therapy and Two-Stage Implant-Based Breast Reconstruction: Is There a Better Time to Irradiate?

“…Since PMRT was first described in 1997 by Overgaard and colleagues, and demonstrated a survival benefit, use of this treatment intervention has become more widespread. 1–7 As a consequence, more patients presenting for breast reconstruction after mastectomy will receive PMRT. 1, 8 As reflected in the overall population of women who undergo breast reconstruction, an increasing proportion of those women who face PMRT will elect to undergo immediate implant-based reconstruction with a two-staged approach.…”

Postmastectomy Radiotherapy: An American Society of Clinical Oncology, American Society for Radiation Oncology, and Society of Surgical Oncology Focused Guideline Update

“…The use of PMRT has been widely accepted for patients with four or more positive lymph nodes, 2,3 but there is still controversy regarding the value of PMRT for those with one to three positive nodes. In 2014, the Early Breast Cancer Trialists' Collaborative Group (EBCTCG) published an updated meta-analysis of the effects of PMRT.…”