Nonrandomized comparison between concomitant and sequential chemoradiotherapy with anthracyclines in breast cancer

Area of Science:

• Oncology
• Radiation Oncology
• Medical Oncology

Background:

• Breast-conserving surgery followed by adjuvant therapy is standard for early-stage breast cancer.
• Optimizing treatment sequencing and delivery is crucial for improving outcomes and minimizing toxicity.
• Anthracycline-based chemotherapy (CHT) and radiotherapy (RT) are common modalities, but their combined use requires careful evaluation.

Purpose of the Study:

• To assess the tolerance and toxicity of concurrent anthracycline-based chemotherapy and 3-dimensional conformal radiotherapy (3D-CRT) after breast-conserving surgery.
• To compare the toxicity profile of concomitant versus sequential administration of CHT and RT.

Main Methods:

• A cohort of 134 patients undergoing breast-conserving surgery were retrospectively analyzed.
• Sixty-seven patients received 3D-CRT concurrently with CHT (CEF or AC regimens).
• This group was compared to 67 patients who received sequential CHT followed by RT.

Main Results:

• The concomitant group experienced significantly higher acute grade ≥2 skin toxicity.
• Hematological toxicity, specifically grade 3-4 leuco-neutropenia, was significantly more frequent in the concomitant group, impacting treatment delivery.
• Radiotherapy duration was longer in the concomitant group due to treatment breaks.
• Late toxicity was generally acceptable, with no symptomatic cardiac or lung events reported. Radiological lung hyperdensity was observed in 27.7% of the concomitant group.

Conclusions:

• Concurrent CHT and 3D-CRT in breast cancer patients leads to increased acute skin and hematological toxicity compared to sequential treatment.
• Despite higher acute toxicities, late toxicity was acceptable, and 3D-CRT may offer advantages over older techniques.
• Hematological toxicity significantly affects the delivery of both CHT and RT, necessitating careful patient monitoring and management.