The clinicopathological characteristics, gene mutation characteristics and survival analysis of carcinoma of unknown primary origin.

Abstract

e15098 Background: Analyze the characteristics of CUPS clinicopathology and gene mutation spectrum, and discuss CUPS drug treatment strategies. Methods: A retrospective analysis of the data of 30 patients with metastatic cancer of CUP admitted to our department from April 2015 to April 2020. Including clinicopathological characteristics, treatment process and methods, gene molecular information, follow-up survival period. The follow-up was until February 1, 2021 or the patient died. Results: The pathological types of these cases were adenocarcinoma (14/30,46.7%), squamous cell carcinoma (5/30, 16.7%), neuroendocrine carcinoma (3/30,10%), small cell carcinoma (2/30,6.7%), sarcomatoid carcinoma (2/30,6.7%), large cell carcinoma (1/30,3.3%), lymphoepithelial carcinoma (1/30,3.3%), and poorly differentiated carcinoma (2/30,6.7%) . The most predilection site was lymph nodes, accounting for 70%. Primary lesions were not found in 23 cases in the course of diagnosis and treatment. They were head and neck in 1 case, lung in 1 case, mammary gland in 1 case, digestive tract in 3 cases and thymus in 1 case. 23 patients received chemotherapy alone or combined with antiangiogenic therapy, 2 patients received molecular targeted agents, 1 patient received ICI combined with antiangiogenic therapy, and the remaining 4 patients died without antitumor therapy or gave up treatment. The survival time of 26 patients was between 1 to 143 months, and the median survival time was 8.6 months. The 1-year, 2-year, 3-year and 5-year OS rate were 40%, 20%, 6.7% and 3.3%, respectively. Mean survival time was significantly longer among patients without visceral metastasis vs. with visceral metastasis (15.6m vs. 7.3m, P = 0.023). OS rate were 70% vs. 25%, 30% vs. 15%, 20% vs. 0% and 10% vs. 0%, respectively. The median survival time were 18.3m (with targeted therapy), 8.8m (without targeted therapy), 23.2m (with primary lesion), 8.4m (without primary lesion), The 1-year, 2-year, 3-year and 5-year OS were 53.3% vs. 26.7%, 40% vs. 0%, 23.3% vs. 0% and 6.7% vs. 0% for patients with targeted therapy vs. without targeted therapy, respectively. The 1-year, 2-year, 3-year and 5-year OS were 85.7% vs. 261%, 42.9% vs. 13%, 28.6% vs. 0% and 14.3% vs. 0% for patients with primary lesion vs. without primary lesion, respectively. 20 patients were interrogated genes using NGS of ctDNA. 80% of patients exhibited ctDNA alterations; TP53-associated genes were most commonly altered (13/20,65%) followed by genes involved in the MAPK pathway (20%), PI3K signaling (10%) and the cell cycle machinery (5%). The genomic profiles help guide treatment in 4 cases. Conclusions: CUPS has a poor prognosis. The pathological type is mostly adenocarcinoma, and lymph node metastasis is the first diagnosis. Chemotherapy is still the main treatment method. Molecular detection is helpful for individualized treatment.