Locally advanced breast cancer: primary ultra-hypofractionated radiotherapy for inoperable or frail patients.

Abstract

Purpose: Locally advanced breast cancer in frail and inoperable patients often causes tumor-associated pain, bleeding, or discharge. These patients may not be suitable for therapeutic options like surgery or potentially toxic systemic treatment. Local radiotherapy with little impact on treatment time may be beneficial in this patient subgroup. We evaluated an ultra-hypofractionated definitive irradiation concept in five fractions (5 × 5 Gy with a simultaneous integrated boost of 5 × 6 Gy) for these patients, focusing on tolerability and clinical outcome.

Methods: A total of 29 patients were retrospectively sampled. They were treated by irradiation to the breast with 25 Gy in five fractions with a simultaneous integrated boost (SIB) of 6 Gy per fraction. Tumor response and clinical outcome were evaluated by clinical examination.

Results: In total, 27 patients with a median age of 82 years were assessed. Median follow-up was 7.4 months. All patients completed radiotherapy with 25 Gy in five fractions with a simultaneous integrated boost of 30 Gy (6 Gy per fraction) without any high-grade toxicity (≥ grade 2). Within the first 90 days after irradiation, 15 patients (56%) exhibited a clinical response and 12 showed stable disease. Only 7 patients reported low-grade acute dermatotoxicity grade 1 (CTCAE) within the first 90 days, and only one experienced toxicity later (fibrosis grade 1, LENT-SOMA).

Conclusion: Radiotherapy in five consecutive daily fractions is sufficient. The studied regimen proved to be a safe, effective palliative treatment in inoperable and frail patients not suitable for surgery or toxic systemic therapy.