Purpose: Carcinoma of unknown primary (CUP) is a clinically aggressive disorder with early tumor dissemination. Identifying molecular traits of CUP can be not only beneficial for a better therapeutic approach but also potentially valuable for patients with general metastatic dissemination.
Patients and methods: We retrospectively investigated a total of 35 unique CUP cases. Tumor tissue samples were available in 26 patients, and plasma samples were available in 22 patients. Targeted sequencing was performed with a panel of 416 pan cancer-related genes.
Results: A genomic landscape of the CUP cohort showed that TP53 mutation was the most frequently observed mutation while MYC amplification was the most common CNV. Aberrant TP53, RTK-RAS, and PI3K signaling pathways were also prevalent, identified in more than half of the cases with tumor tissue. Around 58% of the CUP cases harbored homologous recombinant repair (HRR) pathway gene alterations. The tumor mutational load of CUP patients with altered HRR pathway displayed a significant increase than that of patients with intact HRR. Clinically actionable mutations were identified in eight patients, which may benefit from targeted therapies. Eight patients were treated with platinum-based chemotherapy, showing different responses, HRR, and LOH status.
Conclusion: Collectively, our data have provided much-need insights into the treatment options for patients diagnosed with CUP in the era of precision medicine.
Keywords: DNA damage repair; carcinoma unknown primary; clinically actionable mutation; homologous recombinant repair; targeted therapy.
Copyright © 2022 Yang, Cui, Yu, Dong, Zhao, Dai, Ou, Bao, Wu, Wu and Lai.