‘Valid option’ for partial breast irradiation in breast cancer

The study covered in this summary was published on researchsquare.com as a preprint and has not yet been peer reviewed.

Key takeaway

• Following lumpectomy for early breast cancer, a 1-week schedule of partial breast radiation – 30 Gy delivered in 5 daily fractions – is safe, effective, and convenient for both patients and hospitals.

Why this matters

• According to numerous guidelines, partial breast irradiation after lumpectomy is a sound approach for early-stage breast cancer, but there is a lack of consensus about treatment schedules.
• The investigators suggest that 30 Gy in five daily fractions is a “valid option” for these patients in a field that lacks consensus.

Study design

• The team reviewed 381 women with early breast cancer treated with this approach (30 Gy in five daily fractions) at their center from 2013 to 2022.
• Half of patients had left-sided tumors, 94.5% had invasive ductal carcinomas, 96.6% had grade 1 or grade 2 disease, and tumors were luminal like in 99.2% of patients.
• Following lumpectomy, women underwent partial breast irradiation to the tumor bed plus 15 mm of isometric expansion beyond it.
• Follow-up was a median of 28 months.

Key results

• Seven patients (2%) had a local recurrence, of which two were in the treatment field.
• Three-year local control, disease-free survival, and overall survival were high (97.5%, 95.7%, and 96.9%, respectively).
• Nearly 90% of patients and 97% of physicians reported good or excellent cosmesis.
• Ten patients (2.9%) had grade 2 late toxicities, including edema, asthenia, and fibrosis; there were no grade 3 or higher adverse events.
• Five patients (1.5%) had late cardiac major events, four of whom were treated on the right breast; three patients (0.9%) had late pulmonary fibrosis.
• The safety and efficacy outcomes are in line with previous reports, including those that used different dosage and/or fractionation schedules.

Limitations

• The study was retrospective, with a relatively short follow-up.
• Quality of life was not assessed.
• There was no objective baseline measure of cosmesis against which to compare cosmetic results.

Disclosures

• There was no funding for the study, and the investigators didn’t have any conflicts of interest to report.

This is a summary of a preprint research study, “One-Week External Beam Partial Breast Irradiation: Survival and Toxicity Outcomes,” led by Riccardo Ray Colciago from the Fondazione IRCCS Istituto Nazionale dei Tumori, Milan. The study has not been peer reviewed. The full text can be found at researchsquare.com.

A version of this article first appeared on Medscape.com.