Triple down.

Top Line: Is there an increased risk of recurrence when moderate hypofractionation is used for triple negative breast cancer?

The Study: You may or may not recall as a side note from the 2010 publication of the Canadian hypofractionation trial that the subset of patients with high grade tumors had a higher rate of local recurrence with hypofractionation than with standard fractionation. A subsequent study, though, performed a more in-depth secondary analysis of the trial using modern grading and molecular subtyping and found no increase in recurrence risk based on fractionation. Studies from a Chinese trial and DBCG trial did not find an association among TNBC, hypofractionation, and recurrence risk. This large prospective observational study from the Michigan Radiation Oncology Quality Consortium explored whether triple-negative breast cancer had high recurrence risk with hypofractionation versus conventional fractionation. Among over 500 patients with TNBC who received whole breast radiation (no RNI) at 18 centers, 57% had conventional fractionation and 43% hypofractionation with the majority (93%) having a lumpectomy boost. At 5 years, there was no difference in the rate of freedom from local recurrence (FFLR) with hypofractionation (93.6%) versus conventional fractionation (94.4%). There were also no differences in RFS or OS.

TBL: Hypofractionation is not associated with increased risk of recurrence for women receiving whole breast radiation for TNBC. | Jagsi, Int J Radiat Oncol Biol Phys 2021