Whole-Exome Sequencing Identifies Germline BLM Mutation in Ovarian Hepatoid Adenocarcinoma with Favorable Response to Niraparib and Anlotinib Combination Therapy—A Case Report and Literature Review

Hepatoid adenocarcinoma of the ovary represents a rare and malignant extrahepatic tumor that shares morphological and immunophenotypic similarities with hepatocellular carcinoma. Due to the ambiguous histomorphology and aggressive behavior, the diagnosis and management of hepatoid adenocarcinoma of the ovary present unique challenges. Here, we present a 67-year-old woman with massive ascites and disseminated peritoneal implants at initial diagnosis. She was treated with six cycles of neoadjuvant therapy (albumin-bound paclitaxel + nedaplatin + bevacizumab) and a debulking surgery, followed by eight cycles of postoperative adjuvant therapy (albumin-bound paclitaxel + carboplatin + bevacizumab). Elaborate pathology workup found significant involvement of angiogenesis in the tumor and confirmed the diagnosis via immunohistochemistry. Further molecular characterization of the tumor by whole-exome sequencing (WES) revealed a novel heterozygous germline mutation (NM_000057.2, c.1290_1291delinsATCAGGCCTCCATAG, p.Y430fs1) in gene BLM, likely pathogenic, suggesting a potential candidate for Poly (ADP-ribose) polymerase (PARP) inhibitors. For the maintenance therapy, she received a combination of the PARP inhibitor niraparib and the antiangiogenic anlotinib. As of now, the patient has achieved a partial response, with no apparent evidence of disease progression observed nearly 30 months. Our study sheds light on the WES-based profiling in rare cancers to screen for any treatable targets with otherwise no standard therapeutic options. The promising results with the niraparib–anlotinib combination suggest its potential as a maintenance therapy option for hepatoid adenocarcinoma of the ovary, which warrants validation in future larger cohort.