Optimal Radiation Regimen When Breast Cancer Recurs? Optimal Radiation Regimen When Breast Cancer Recurs?

The study covered in this summary was published on Research Square as a preprint and has not yet been peer reviewed.

Key Takeaway

  • Among patients with recurrent or new primary breast cancer, a second breast conserving surgery followed by re-irradiation was safe and effective across a range of radiation fractionation regimens.

Why This Matters

  • Salvage mastectomy has been the standard of care when breast cancer survivors have a recurrent or new primary tumor.

  • Lumpectomy and re-irradiation have emerged as a viable alternative, but data on the safety and efficacy of different radiation fractionation options remain limited.

  • The current study suggests that once daily and hypofractionated regimens are a safe and effective alternative to conventional, twice-daily radiation.

Study Design

  • The investigators reviewed outcomes in 66 breast cancer survivors who underwent lumpectomy and re-irradiation for recurrent or new primary tumors.

  • At the time of recurrence, 41% had invasive carcinoma with a ductal carcinoma in situ (DCIS) component, 41% had invasive carcinoma alone, and 18% had DCIS alone.

  • Most of the women had early-stage, hormone receptor positive and HER2 negative disease, and all were node negative.

  • Following surgery, 95% had partial breast irradiation, including 57.5% with 45 Gy delivered in 1.5 Gy fractions twice daily; 27% with 45 Gy in 1.8 Gy fractions once a day; and 10.5% with hypofractionated regimens ranging from 2.6-8 Gy per fraction.

  • The remaining women had approximately 45 Gy of whole breast irradiation in 1.8-2 Gy fractions.

Key Results

  • At 2 years, overall survival and locoregional recurrence-free survival were both 100%; distant metastasis-free survival was 91.6%.

  • Only two patients experienced late, grade 3 radiation adverse events: telangiectasia at 1 year and fibrosis at 3 years; no grade 4 or 5 events occurred. 

  • Fractionation regimen selection and cumulative dose were not associated with acute or late toxicity.

Limitations

  • It was a retrospective study with limited follow-up and a small study population.

  • Only a few patients received hypofractionated and ultrahypofractionated radiation. 

  • There were differences in adverse event reporting between the two participating institutions.

Disclosures

This is a summary of a preprint research study, “Effectiveness and toxicity of re-irradiation after breast conserving surgery for recurrent or new primary breast cancer: a multi-institutional study,” led by Camille Hardy Abeloos of the NYU Langone Medical Center, New York City, provided to you by Medscape. The study has not been peer reviewed. The full text can be found at researchsquare.com.

M. Alexander Otto is a physician assistant with a master’s degree in medical science and a journalism degree from Newhouse. He is an award-winning medical journalist who has worked for several major news outlets before joining Medscape and also an MIT Knight Science Journalism fellow. Email: aotto@mdedge.com.