Triple-negative breast cancer: partial response to TAC chemotherapy

What happened, in summary

A 71-year-old woman from Hebei Province had noticed a small left-breast lump about 20 years earlier, when it was roughly the size of a fava bean. It was painless and caused no nipple discharge or skin redness, so she did not seek care. Over 2 decades, the mass slowly enlarged until it was about the size of a cantaloupe, protruding from the skin in a cauliflower-like shape. On February 3, 2024, it ulcerated and bled, leading to hospital admission. Examination showed a hard, fixed, irregular 30 x 25 cm mass with purulent discharge, foul odor, local skin ulceration, bleeding, and cellulitis-like redness and swelling. Several movable left axillary nodes were palpable. CT and preoperative biopsy supported a malignant breast tumor. Immunohistochemistry showed ER-negative, PR-negative, HER2-negative disease, making it triple-negative. The tumor was also EGFR-positive, BRCA1-positive by immunohistochemistry, p63-positive, E-cadherin-positive, P120 membrane-positive, and TRPS-1-positive, with Ki-67 at 50%; CK5/6 was negative and several markers were partially positive. She received neoadjuvant TAC chemotherapy: doxorubicin hydrochloride liposome injection 40 mg, cyclophosphamide 800 mg, and albumin paclitaxel 400 mg by intravenous drip. After 1 cycle and 21 days, the breast mass had shrunk enough for surgery. She underwent radical mastectomy of the left breast with adjacent flap transfer. Pathology showed classic adenoid cystic carcinoma, cT4N1M0, with no cancer in surgical margins, papillary muscle, pectoralis major or minor muscles, or examined lymph nodes. Her wound healed well, and she was recovering before planned postoperative AC-T chemotherapy. The first postoperative day was uncomplicated, with no redness, wound rupture, or other inflammatory signs, and she reported no obvious discomfort.