Concurrent Chemotherapy With Adjuvant Radiation for Patients With High-risk Locally Advanced Breast Cancer: Safety...

Concurrent chemoradiation (chemoXRT) enhances the efficacy of adjuvant radiation by radiosensitizing microscopic residual disease and may improve locoregional control. We report our institutional experience using adjuvant chemoXRT for high-risk breast cancer patients.

We conducted a retrospective study of patients with stage II-III invasive breast cancer treated with chemotherapy, surgery, and adjuvant chemoXRT between 2006 and 2019. The use of chemoXRT was based on provider discretion. Locoregional recurrence (LRR) was the primary outcome. Secondary outcomes included distant recurrence, disease free survival (DFS), overall survival (OS), and toxicity. LRR incidence was estimated with distant recurrence and death as competing risks. DFS and OS were estimated using the Kaplan-Meier method.

Forty-two patients met inclusion criteria; 35 (83%) patients received treatment at primary diagnosis and 7 (17%) for a LRR. In the primary setting, 91% had stage III disease. Of the patients who received neoadjuvant chemotherapy (71%), all had residual disease in the breast or lymph nodes. The majority received comprehensive regional nodal irradiation (40, 95%) with a median total dose of 57 Gy (range: 45-68 Gy). Concurrent chemotherapies included capecitabine, cisplatin, or paclitaxel. At median follow-up of 5 years, LRR risk was 7% (95% CI: 2%-21%). DFS was 47% (95% CI: 34%-65%) and OS was 56% (95% CI: 42%-74%). ChemoXRT was well tolerated with expected rates of dermatitis and no new toxicity signals.

Concurrent chemoXRT was safe and showed promise as a method to decrease risk of local recurrence in high-risk patients. Prospective evaluation is needed.