by Van der Vorst Aline, Kindts Isabelle, Laenen Annouschka,
Neven Patrick, Janssen Hilde, Weltens Caroline
The Breast: Published: April 16, 2022
Background
To date, it remains unclear which patients with breast
cancer (BC) benefit from post-mastectomy radiotherapy (PMRT). Cheng et al.
developed and validated a scoring system based on 4 prognostic factors for
locoregional recurrence (LRR) to identify patients in need for PMRT. These
factors include age, estrogen receptor status, lymphovascular status and number
of affected axillary lymph nodes.
Purpose
To validate the scoring system for LRR in BC developed by
Cheng et al. by using an independent BC database.
Methods and materials
We retrospectively identified 1989 BC cases, treated with
mastectomy (ME) with or without PMRT at the University Hospitals Leuven between
2000 and 2007. The primary endpoint was 5-year locoregional control rate with
and without PMRT, according to the LRR score.
Results
Median follow-up time was 11.4 years. After excluding
patients with missing variables 1103 patients were classified using the LRR
scoring system: 688 (62.38%) patients were at low risk of recurrence (LRR score
0–1), 335 (30.37%) patients were at intermediate risk of recurrence (LRR score
2–3) and 80 (7.25%) patients were at high risk of recurrence (LRR score ≥4).
5-year locoregional control rates with and without PMRT were 99.20% versus
99.21% (p = 0.43) in the low-risk group; 98.24% versus 85.74% (p < 0.0001)
in the intermediate-risk group and 96.87% versus 85.71% (p = 0.10) in the
high-risk group respectively.
Conclusion
Our validation of the LRR scoring system suggests it can be
used to point out patients that would benefit from PMRT. We recommend further
validation of this scoring system by other independent institutions before
application in clinical practice
