A rare case of recurrent ovarian cancer with <i>TPM3‑NTRK1</i> gene rearrangement: A case report

Abstract

<i>NTRK</i> gene fusion is rare in gynecological cancer. Entrectinib is a novel targeted drug, which is a potent inhibitor of TRK A, B and C. The present case report described a case of recurrent ovarian cancer with <i>TPM3-NTRK1</i> rearrangement, which was detected by next-generation sequencing (NGS) and treated with entrectinib. A 56-year-old woman was diagnosed as having stage IV ovarian cancer with positive pleural fluid cytology. Neoadjuvant chemotherapy and interval debulking surgery, followed by chemotherapy, were performed. A total of 10 months after completion of chemotherapy, the disease recurred and the patient was treated with multimodal therapy for recurrence. DNA-based NGS detected <i>TPM3-NTRK1</i> rearrangement and entrectinib therapy was initiated; however, the disease progressed despite 6 weeks of entrectinib administration, and 1 month after discontinuation of entrectinib, the patient died. After their death, immunohistochemistry with a pan-Trk monoclonal antibody was performed to determine the expression levels of TRK; however, immunohistochemistry was negative for TRK. In conclusion, the present case report described a rare case of recurrent ovarian cancer with <i>TPM3-NTRK1</i> gene fusion, in which entrectinib was not effective. While <i>NTRK</i> gene fusion was detected by DNA-based NGS, immunohistochemistry was negative for TRK. These findings indicated that immunohistochemistry may be required for confirmation of TRK protein expression prior to entrectinib administration.