AFP and neoplasm: The patient received first-line chemotherapy with carboplatin-etoposide (eight cycles), achieving a partial response marked by a significant decrease in AFP levels (from 39,775 to 160 μg/L, N < 7 μg/L) and partial regression in both size and number of hepatic metastases on follow-up thoraco-abdominal CT imaging. In the absence of a validated specific tumor marker for high-grade NECs, AFP - despite its lack of specificity - was used as a surrogate biomarker for disease monitoring, given its markedly elevated baseline level and dynamic correlation with the tumor’s clinical course.