Pure Squamous Cell Carcinoma of Breast which got Long Duration Response and Survival by Sequential Chemotherapy with Combination of Paclitaxel + Bevacizumab, and S-1 Under Limited Treatment Strategy: A Case Report
Pure Primary Squamous Cell Carcinoma of Breast (SCCB) is extremely rare and aggressive. This study presents a case of 77-year-old woman with rapid-growing ulcerating 6 cm left breast mass and comorbidity of nontuberculous mycobacterial infection. SCCB was diagnosed by fine-needle aspiration biopsy, and smears characterized by Triple-Negative Breast Cancer (TNBC). Modified radical mastectomy with axillary lymph node dissection was performed, followed by adjuvant radiotherapy and 4 cycles of chemotherapy: weekly Paclitaxel (PTX) + Bevacizumab (Bmab). After progression, capecitabine was administered until lung metastasis was detected. Subsequently, two regimens (Atezolizumab + nab-PTX and eribulin) revealed progressive disease. Next, oral Tegafur/Gimeracil/Oteracil (S-1) was administered, and partial response in lung metastasis revealed for 5 months. However, cerebellar metastasis was detected newly, palliative radiation therapy and intracranial decompression performed. After radiation, patient’s general condition worsened gradually, and best supportive care was initiated in palliative care unit. She died due to tumor progression 29 months after diagnosis.
We also analyzed 117 case reports of Japanese SCCB up to 2021 from Japan Medical Abstracts Society. SCCB has unique biological characteristics, including low estrogen and progesterone receptor levels. Issue of adjuvant chemotherapy remains unsolved owing to lack of data. Treatment strategy should be tailored to fit its distinct biological characteristics. Given high risk of SCCB, this report presents important findings for postoperative treatment. Bmab is to be warranted in combination with PTX for TNBC, along with radiation for heavily treated immunosuppressed metastatic breast cancer. Furthermore, S-1 was effective and feasible without an anti-emetic steroid in our case.