Radiotherapy Strategies for Stage II Breast Cancer With Lymphovascular Invasion After Mastectomy.
Lymphovascular invasion (LVI) is a strong prognostic factor associated with poor survival outcomes in breast cancer. However, the clinical benefit of postmastectomy radiotherapy (PMRT) for early-stage disease remains uncertain. This study aimed to evaluate PMRT efficacy and related prognostic factors in real-world settings.
We retrospectively analyzed 322 postoperative breast cancer patients with pathologically confirmed LVI who received radiotherapy (RT) between October 2017 and July 2020. Patients were categorized into two groups: Group A (pT1-2N1M0, n=273), who underwent modified radical mastectomy (MRM) with or without adjuvant RT; and Group B [stage II, ypN0 after neoadjuvant chemotherapy (NAC) and surgery, with or without adjuvant RT, n=49]. Intergroup differences were assessed using the chi-squared test, and Kaplan-Meier analysis estimated local recurrence-free survival (LRFS), disease-free survival (DFS), overall survival (OS), and distant DFS (DDFS).
Group A: Patients who received adjuvant RT had significantly improved 5-year LRFS (94.4% vs. 85.5%, HR=0.359, 95% CI=0.147-0.879; p<0.05) and DFS (88.9% vs. 78.8%, HR=0.488, 95% CI=0.253-0.940; p<0.05) compared to those without RT. No significant difference was observed in 5-year OS or DDFS. Subgroup analysis indicated a higher recurrence risk among patients with two to three positive lymph nodes or triple-negative tumors. Group B: Among patients who achieved ypN0 status, adjuvant RT significantly improved 5-year DFS (95.8% vs. 76.0%), OS (100.0% vs. 84.0%), and DDFS (100.0% vs. 80.0%) (p<0.05), with no significant difference in LRFS.
In stage II LVI-positive breast cancer patients, adjuvant RT improves local control and leads to an increase in DFS but not OS. PMRT provides survival benefits for LVI-positive patients who achieve ypN0 status after NAC and is recommended. Larger studies are needed to validate these findings.
We retrospectively analyzed 322 postoperative breast cancer patients with pathologically confirmed LVI who received radiotherapy (RT) between October 2017 and July 2020. Patients were categorized into two groups: Group A (pT1-2N1M0, n=273), who underwent modified radical mastectomy (MRM) with or without adjuvant RT; and Group B [stage II, ypN0 after neoadjuvant chemotherapy (NAC) and surgery, with or without adjuvant RT, n=49]. Intergroup differences were assessed using the chi-squared test, and Kaplan-Meier analysis estimated local recurrence-free survival (LRFS), disease-free survival (DFS), overall survival (OS), and distant DFS (DDFS).
Group A: Patients who received adjuvant RT had significantly improved 5-year LRFS (94.4% vs. 85.5%, HR=0.359, 95% CI=0.147-0.879; p<0.05) and DFS (88.9% vs. 78.8%, HR=0.488, 95% CI=0.253-0.940; p<0.05) compared to those without RT. No significant difference was observed in 5-year OS or DDFS. Subgroup analysis indicated a higher recurrence risk among patients with two to three positive lymph nodes or triple-negative tumors. Group B: Among patients who achieved ypN0 status, adjuvant RT significantly improved 5-year DFS (95.8% vs. 76.0%), OS (100.0% vs. 84.0%), and DDFS (100.0% vs. 80.0%) (p<0.05), with no significant difference in LRFS.
In stage II LVI-positive breast cancer patients, adjuvant RT improves local control and leads to an increase in DFS but not OS. PMRT provides survival benefits for LVI-positive patients who achieve ypN0 status after NAC and is recommended. Larger studies are needed to validate these findings.