The Role of Postmastectomy Radiotherapy in Locally Advanced Breast Cancer After Pathological Complete Response to Neoadjuvant Chemotherapy

摘要

A previously healthy woman, aged 32 years, presented to the oncology clinic with a 6-month history of left-breast tumor, mastalgia, and swollen axillary nodes. Physical examination was relevant for a 6-cm palpable mass in the upper outer quadrant of the left breast and an ipsilateral 2-cm, nonfixed axillary lymph node. Mammography showed a 1-cm mass in the upper outer quadrant, a 5.2-cm mass in the lower outer quadrant, and enlarged pathologic lymph nodes (BI-RADS category 5 disease]. Breast ultrasound revealed 3 axillary lymph nodes with cortical thickening and loss of normal morphology [the largest with a 2.6-cm length in the long axis] (Figure 1A-B). The breast's core biopsy revealed a grade 3 apocrine invasive carcinoma with lymphovascular invasion; immunohistochemistry testing showed HER2-nega-tive, hormone receptor-negative disease (estrogen receptor, 0%; progesterone receptor, 0%; HER2-negative, Ki67,50%] (Figure 2A-B). A fine-needle aspiration biopsy of the axillary lymph nodes showed invasive breast carcinoma as well. Bone scintigraphy and a chest/abdomen CT scan ruled out metastatic disease. Upon initial diagnosis, clinical stage was deemed as cT3Nl MO (American Joint Committee on Cancer 8th edition: anatomic stage IIIA, clinical prognostic stage IIIC].