A Dose Escalation Study of Proton and Carbon Ion Irradiation for HER2 Positive and Triple Negative Breast Cancer

Adjuvant radiotherapy is the standard treatment for early breast cancer after breast conserving surgery. Molecular subtypes was significantly associated with the risk of local recurrence of breast cancer. Nguyen et al found that the overall 5-year cumulative incidence of local recurrence was 0.8% for luminal A, 1.5% for luminal B, 8.4% for HER2 positive, and 7.1% for triple negative breast cancer after lumpectomy and radiotherapy. Her2 positive and triple negative breast cancers may be inherently radioresistant.Therefore, for HER2 positive and triple negative breast cancer with high local recurrence and radiation resistance, proton combined with carbon ion is proposed after breast conserving surgery.

Inclusion Criteria:Histologically confirmed HER2 positive or Triple Negative invasive breast carcinoma.(HER2 positive: immunohistochemistry [IHC] 3+ and or fluorescence in situ hybridization [FISH] amplified; Triple Negative: estrogen receptor [ER] and progesterone receptor [PR] < 1%, HER2 negative [IHC 1+ or 2+ FISH non-amplified])Age ≥ 18 years and ≤ 80 years.The primary tumor must be excised via breast conserving surgery.Stage p T1-2 N0 M0ECOG performance status ≤2.Exclusion Criteria:Invasive breast cancer not confirmed by pathology.Distant metastasisPrior thoracic radiation.Pregnancy or lactating.