Change of HER2 status during disease recurrence predicts good prognosis for primary squamous cell carcinoma of the breast

Abstract

Rationale:Primary squamous cell carcinoma (PSCC) of the breast is one of the least common types of breast cancer. Adjuvant treatment for PSCC remains an unresolved issue.Patient concerns:We reported a case of a 48-year-old postmenopausal female patients with a 2 × 2.5 cm lump presented with no symptoms.Diagnoses:This patient was diagnosed as PSCC of the breast. The original tumor and first recurrence exhibited triple negative phenotype, whereas the second recurrence was HER2-positive.Interventions:A tumorectomy with latissimus dorsi flap reconstruction for the second recurrence was performed followed by targeted therapy with trastuzumab.Outcomes:The patient had a complete remission, which was sustained over the 25 months of follow-up after the tumorectomy.Lessons:This is the first reported case in literature of a breast PSCC patient with switched immunohistochemical phenotypes during disease recurrence. Surgical resection with flap reconstruction and targeted therapy successfully treated the recurrence.

Case report: Apatinib combined with neoadjuvant therapy for primary squamous cell carcinoma of the breast: a case report

“…PSCC has no standard treatment (Yoneto et al, 2018;Alan et al, 2019;Cao et al, 2019;Lei and Miao, 2020). Squamous cell carcinoma of the breast is resistant to standard chemotherapy with IDC (cyclophosphamide, methotrexate, 5-FU, and adriamycin) (Chen et al, 2022).…”

Primary tumor resection for initially staged IV breast cancer

“…This discordance is similar to the discrepancy in the ER, PR, and Her-2 statuses of the primary breast tumor and its distant metastatic foci, a well-documented phenomenon in breast cancer, which might also have an impact on treatment strategies. [3,31,32,33] Even though our study is limited by its small sample size and use of tissue microarrays instead of whole surface sections, we observed similar discordance in PD-L1 expressions of the primary tumor, lymph node, and distant metastasis, and our results were comparable to previous studies that reported the conversion of PD-L1 status in triple negative breast cancer patients [34] . Manson et al reported a PD-L1 (on tumor) discordance between primary tumors and matched distant metastases in 28.5% of the patients with breast cancer [35] .…”