CASE REPORT article
Front. Oncol.
Sec. Cancer Molecular Targets and Therapeutics
This article is part of the Research TopicBreaking Barriers: New Frontiers in Immunotherapy for Resistant CancersView all 9 articles
Targeted and Immunotherapy Based on Tissue of Origin in Carcinoma of 1 Unknown Primary: A Two-Case Report and Literature Review
Provisionally accepted
- The First People’s Hospital of Lianyungang, Lianyungang, China
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Background: Patients with carcinoma of unknown primary (CUP) 10 generally have a poor prognosis due to the lack of effective treatment 11 options resulting from unclear diagnosis. Determining the tumor type 12 through tumor origin testing, followed by cancer-specific genetic testing 13 and precision therapy, may potentially improve the prognosis of CUP 14 patients. 15 Case Presentation: Case 1: A 44-year-old male patient presented to a 16 local hospital with lower limb pain. A bone biopsy pathological report 17 from our hospital indicated metastatic carcinoma in the bone lesion. The 18 90-gene expression analysis yielded a similarity score of 56.9, suggesting 19 a high probability of lung cancer origin. Based on the genetic testing and 20 combined with immunohistochemistry results, the diagnosis was 21 metastatic adenocarcinoma. Subsequently, the bone biopsy tissue was 22 tested for Epidermal growth factor receptor/Anaplastic Lymphoma 23 Kinase/ROS proto-oncogene 1 (EGFR/ALK/ROS1) gene mutations, 24 which revealed an EGFR exon 19 deletion (19Del) mutation. Based on 25 the above results, the patient received chemotherapy with carboplatin and 26 pemetrexed disodium combined with targeted therapy using the EGFR 27 tyrosine kinase inhibitor (TKI) almonertinib mesylate tablets. Based on 28 the molecular evidence provided by the tumor origin test results, a 29 diagnosis was established for the patient by the clinician, and 30 corresponding treatment plans were formulated accordingly. 31 Unfortunately, after three cycles of treatment, the patient discontinued 32 therapy due to other issues and was lost to follow-up. 33 Case 2: A 59-year-old male patient sought medical attention in May 2021 34 due to dysphagia. He underwent radical esophagectomy for esophageal 35 cancer at an external hospital, with postoperative pathological diagnosis 36 of esophageal squamous cell carcinoma. In August 2024, he presented 37 with cervical lymph node enlargement.
Keywords: Cancer, Carcinoma of unknown primary, case report, Targeted and immunotherapy, Test of tumor origin
Received: 07 Nov 2025; Accepted: 11 Feb 2026.
Copyright: © 2026 Wang, Yan, Sun and Liang. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Mei Wang
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