Is Pathologic Complete Response the Surrogate in Primary Gastric Angiosarcoma Undergoing Doxorubicin-Based Neoadjuvant Chemotherapy? A Case Report

INTRODUCTION: Angiosarcoma is a malignant tumor with low incidence. Especially in the advanced tumors, there is still a lack of knowledge of evidence-based medicine. CASE PRESENTATION: We report a case of a 55-year-old woman with abdominal pain of 2 months of duration, which had increased in severity for 2 weeks prior to the presentation. The diagnosis is primary gastric angiosarcoma. We performed multiple disciplinary team (MDT), and doxorubicin-based neoadjuvant chemotherapy (NAC) was proposed. After two cycles of NAC, a computed tomography (CT) scan showed complete regression compared with the previous scan. An open surgery was done, and surgical specimens were confirmed as a pathological complete response (PCR) by pathological and immunohistochemical examination, but unfortunately, the patient suffered a relapse after the surgery in 3 months. CONCLUSION: Repeated endoscopic biopsy and biopsy specimen examinations can improve accuracy in diagnosis. It seems that NAC could be a candidate for advanced primary gastric angiosarcomas. But after the rapid relapse, we are wondering whether pathologic complete response is the surrogate in primary gastric angiosarcoma undergoing NAC.