A locally advanced primary gastric adenocarcinoma with a choriocarcinomatous component successfully treated by FLOT chemotherapy and surgery: A case report and literature review

Gastric adenocarcinoma with choriocarcinomatous component (GACC) is a rare tumor, accounting for less than 1% of all gastric neoplasms and associated with poor prognosis. Due to the rarity of this entity, clinical features, diagnosis criteria, prognosis, and treatment strategies are not well defined. By analogy with other germ cells tumors, the polychemotherapy regimen containing bleomycine, etoposide and cisplatin is traditionally used.We report the case of a young female patient, initially referred for ectopic pregnancy, diagnosed with locally advanced GACC after radiological and endoscopic examinations. To characterize the biopsy's molecular alterations, we performed DNA sequencing on both components, showing that they shared common variants supporting the hypothesis that the tumor arises from a common clone. We decided to treat our patient with the modified FLOT regimen which is recommended for gastric adenocarcinoma. The rapid clinical improvement and decrease of β-hCG after 2 cycles was an early sign of activity, confirmed by the complete disappearance of initial gastric hypermetabolism on the 18FDG-PET and the almost complete pathologic response found in the resected specimen. The patient is still in complete remission sixteen months after surgery. Multidisciplinary treatment for GACC including standard adenocarcinoma FLOT chemotherapy and radical surgery was effective and well tolerated in a patient with locally advanced gastric adenocarcinoma and choriocarcinoma component. This strategy is promising in a rare disease with poor survival but warrant further studies.