Hypofractionated partial breast irradiation after breast-conserving surgery for patients with early stage breast cancer in China Mainland: a single-arm prospective trial.

Summary

In 208 evaluable low-risk early breast cancer patients treated with IMRT-PBI (40.05 Gy in 15 fractions), 3-year cosmetic deterioration was 3.5%. Grade 2 dermatitis occurred in 5.8% and induration in 1.5%, with no ≥ grade 2 breast pain, edema, or telangiectasia. Five-year ipsilateral recurrence was 0.5%, DFS 99.0%, and OS 97.9%.

Key Findings

• 3-year cosmetic deterioration rate was 3.5%
• Grade 2 dermatitis 5.8% and breast induration 1.5%; no ≥ grade 2 pain, edema, or telangiectasia
• 5-year ipsilateral breast tumor recurrence 0.5% and regional recurrence 0.5%
• No distant metastases; 5-year DFS 99.0% and OS 97.9% (4 non-breast cancer deaths)

Clinical Implications

For carefully selected low-risk patients after breast-conserving surgery, IMRT-PBI (40.05 Gy/15 fractions) is a compelling option balancing tumor control and cosmetic outcomes with low toxicity; comparative trials are needed to confirm equivalence vs. whole-breast irradiation.

Limitations

• Single-arm design without a control group limits causal inference
• Restricted to low-risk population; generalizability may be limited

Future Directions

Head-to-head randomized trials versus whole-breast irradiation and other PBI schedules, with standardized patient-reported cosmetic outcomes and longer follow-up.