Objective: The aim of this study was to compare Conventional fractionated radiotherapy (CFRT) and Hypofractionated radiotherapy (HFRT) in terms of treatment outcomes, such as in 5-year loco-regional recurrence free survival, disease free survival, overall survival, and distant metastatic free survival rates as well as toxicity.
Materials and methods: We retrospectively analyzed the data obtained from 462 breast cancer patients who received complete adjuvant radiotherapy treatment between January 2012 and December 2014. One hundred twenty eight patients received CFRT 2 Gy daily fractions at a total dose of 48-60 Gy (group 1), while 334 patients received HFRT 2.65-2.67 Gy daily for 15-19 fractions at a total dose of 39.7-47.8 Gy 9 (grup 2). Treatment outcome such as 5-year loco-regional recurrence free survival, disease free survival, overall survival, and distant metastatic free survival rates as well as toxicity were measured and compared between two groups.
Results: Median follow-up was 65.7 months (ranging from 45.1 to 95.2 months). Five-year loco-regional recurrence free survival rate was 96.1% in both CFRT and HFRT groups (p=0.993). Five-year disease-free survival rate of CFRT group was higher (68.8%), but this difference was not significant (HFRT =63.5%) (p=0.396). These were complied with 5-year overall survival rate (71.9% and 64.7%, p=0.385). Five-year distant metastatic free survival rate was 85.9% in CFRT group and 79.6% in HFRT group (p=0.169). No difference was observed between two groups in terms of toxicities, including changes in chest wall appearance, skin fibrosis, brachial plexopathy, arm edema, pulmonary fibrosis, and cardiovascular events.
Conclusion: The treatment outcomes of hypofractionated radiotherapy in the postmastectomy breast cancer patients is comparable to the outcomes of conventional treatment at the Chonburi Cancer Hospital as previously reported from other studies, and HFRT can be implemented in resource-limited settings.
Keywords: conventional radiotherapy; hypofractionated radiotherapy; postmastectomy breast cancer.