A case of advanced esophagogastric junction cancer in which comprehensive genomic profiling by liquid biopsy led to the diagnosis of a second primary hepatocellular carcinoma.

内容摘要

The primary objective of comprehensive genomic profiling (CGP) is to identify actionable genomic alterations. We report a case in which CGP performed by liquid biopsy (LB) led to the diagnosis of multiple primary cancers. A 66-year-old man was diagnosed with unresectable esophagogastric junction cancer and received systemic chemotherapy. Initially, all distant metastases disappeared; however, a new liver tumor-first suspected to be a metastasis-appeared and gradually enlarged, while the other lesions remained controlled. CGP by LB, performed after initiation of fifth-line chemotherapy, detected genomic alterations suggestive of hepatocellular carcinoma (HCC). Subsequent liver biopsy confirmed the liver tumor, initially thought to be a metastasis, as a second primary HCC. This case suggests that CGP by LB may provide an opportunity to detect multiple primary cancers. When genomic alterations that are inconsistent with the clinical diagnosis are identified, the possibility of multiple primary cancers should be considered.