Hypofractionated radiotherapy in young versus older women with breast cancer: a retrospective study from India

BACKGROUND: Young women with breast cancer (BC) are not represented in the trials on hypofractionation. In this study we compared outcomes in young patients with BC to their older counterparts treated with hypofractionated radiotherapy (RT) in a regional cancer centre in India. MATERIALS AND METHODS: Between January 1990 to December 2010, women with BC, treated with hypofractionated RT dose of 35–40 Gy/15#/3 weeks were divided into two groups, ≤ 35 years and > 35 years. Outcomes compared were locoregional recurrence rate (LRR), locoregional recurrence-free survival (LRRFS), disease-free survival (DFS), overall survival (OS) and toxicities. LRRFS, DFS and OS were estimated using the Kaplan-Meier method. RESULTS: Of total 2244 patients, 359 were ≤ 35 years of age and 1885 were > 35 years. Patient and disease characteristics were comparable between the two groups, except that comorbidities were significantly higher in the > 35 years age group, more patients aged ≤ 35 years had nodal N3 disease, received chemotherapy and RT to internal mammary nodes and more patients in the > 35 years group received hormonal therapy. Median follow up was 10 years (range 1–30 years). LRR and distant metastases were comparable between the two groups. However, synchronous LRR and distant metastases were significantly higher in the ≤ 35 years group 18 (5.1%) as compared to the > 35 years group 39 (2.1%) with p = 0.018. Estimated 10-year LRRFS, DFS and OS were 92% vs. 94% (p = 0.95), 68% vs. 73%(p = 0.058) and 78% vs. 76% (p = 0.10) in ≤ 35 years and > 35 years, respectively. OS for stage 1 was comparable between the two groups. However, for stage 2 and 3 it was 77% vs. 82% (p = 0.048) and 53% vs. 62% (p = 0.045) in the ≤ 35 years and > 35 years group, respectively. Acute and late toxicity were similar in the two groups. CONCLUSION: Young BC patients had higher LRR and distant metastases. LRRFS, DFS and toxicities were comparable between the two groups. However, OS was poorer in young BC patients with stage 2 and 3 disease.