Patient-Reported Outcomes Between Whole-Breast Plus Regional Irradiation and Whole-Breast Irradiation Only in pN1 Breast Cancer After Breast-Conserving Surgery and Taxane-Based Chemotherapy: A Randomized Phase 3 Clinical Trial (KROG 17-01)

Purpose: The role of regional node irradiation (RNI) with whole-breast irradiation (WBI) in patients with pN1 breast cancer receiving taxane-based adjuvant chemotherapy is not well defined. The KROG 1701 trial, a phase 3, multicenter, noninferiority study, aimed to compare the disease-free survival between WBI+RNI and WBI alone in this patient cohort. Comprehensive patient-reported outcomes (PROs) collected at multiple timepoints are reported. Methods and Materials: The trial (NCT03269981) enrolled patients with pN1 breast cancer after breast-conserving surgery and taxane-based adjuvant chemotherapy, allocating them to receive either WBI+RNI or WBI only. PROs were assessed using European Organization for Research and Treatment of Cancer Quality-of-Life Questionnaires Core 30and breast cancer-specific module 23 modules at baseline, during radiation therapy, and at subsequent follow-up intervals of 3 to 6 months, and annually up to 4 years. Results: From April 2017 to December 2021, 840 patients were enrolled; 777 received intervention as assigned, and 750 completed baseline PRO questionnaires (387 in WBI+RNI, 363 in WBI only). All PRO domains showed improvements over time (P < .001). During radiation therapy, the WBI+RNI group reported greater fatigue and nausea. Higher arm symptom scores were observed in the WBI+RNI group 3 months post-treatment (P = .030). No other significant PRO domain differences, including arm/breast symptoms, were observed between the 2 groups. Conclusions: In patients with pN1 breast cancer treated with taxane-based chemotherapy, adding RNI to WBI resulted in minor, temporary declines in specific PRO domains, but these differences were not clinically significant. This indicates that overall patient experience between WBI+RNI and WBI is comparable, supporting the safety and patient tolerability of both treatments.