Evaluating the value of neoadjuvant radiotherapy in patients with breast cancer

The benefits of preoperative neoadjuvant radiotherapy (NART) for breast cancer are not conclusive and there are no well-established guidelines for NART. We aimed to analyze the difference in survival benefit between NART and postoperative adjuvant radiotherapy (PORT) and screening patients who are suitable for NART.

A retrospective cohort study using the Surveillance, Epidemiology, and End Results (SEER) from 2010 to 2021 was performed. We comprehensively assessed trends in the management of NART in the population during the past decade. The factors associated with NART were then explored using logistic regression. We also compared BC patients with preoperative neoadjuvant radiotherapy (NART) or postoperative adjuvant radiotherapy (PORT) for overall survival (OS) and breast cancer-specific survival (BCSS) after propensity score matching (PSM), and attempted to identify precise subgroups of patients that could benefit from NART.

1785 patients receiving NART were identified from a total of 274,199 patients between 2010 and 2021, with a median follow-up time of around 58 months. NART utilization in higher tumor stages shows a slight upward trend. Based on the multivariate logistic regression model, age more than 50 years old (OR = 0.86; 95% CI 0.78 to 0.94), stage II-III (II: OR = 1.49; 95% CI 1.28 to 1.74 III: OR = 2.44; 95% CI 1.98 to 3.00), T4 (OR = 1.52; 95% CI 1.25 to 1.84), HR-/HER2- (OR = 0.8; 95% CI 0.70 to 0.92) were independently correlated with NART. PORT was significantly associated with better survival (P < 0.001, HR = 0.6709; 95% CI 0.5898-0.7630 for OS) after propensity score matching (PSM). Subgroup analyses showed that for patients of HR-/HER2- subtype, AJCC stage I category or patients receiving breast-conserving surgery (BCS), NART and PORT resulted in similar OS and BCSS. We also identified risk factors for second primary malignancies development after breast cancer and found that NART were related to the lower risk of developing second primary malignancies following breast cancer.

Over time, an increasing number of breast cancer patients received NART. We cannot affirm that NART is as effective as PORT in the treatment of BC, however we can consider NART as an alternative option in some contexts such as patients of AJCC stage I category and patients receiving BCS, given its potential advantages of reducing second primary malignancies risk.