Overall, there was no evidence that any of the hypofractionated radiotherapy regimens investigated in the randomised controlled trials was associated with a statistically significant difference in local recurrence rate or a significantly worse overall survival rate when compared to a conventionally fractionated regimen. However, subgroup analysis of one randomised controlled trial6 showed adverse local control outcomes for patients with a high grade tumour treated with hypofractionated radiotherapy after breast conserving surgery. This has not been confirmed in other trials. There were some differences in adverse events, toxicity and cosmetic outcomes, although they were not consistent across the hypofractionated radiotherapy protocols.
These results should be considered in the context of the included patient populations, statistical power of the trials, variations in the hypofractionated radiotherapy regimens used and lengths of follow-up. There were insufficient patient numbers in the trials to make a definitive recommendation about the integration of systemic therapy, regional nodal radiotherapy and tumour bed boost in patients who receive hypofractionated radiotherapy. Adverse events including cosmetic outcomes are important considerations for women receiving radiotherapy. Clinicians should consider and discuss with women the absolute benefits and harms when considering a hypofractionated radiotherapy regimen.