KEY TAKEAWAYS
- The Arcagen study aimed to delineate the molecular characteristics of rare cancers to guide treatment.
- The study reported significant genomic changes in 63% of the uncommon thoracic tumors, expanding treatment choices for roughly 30% of the pts.
In the study, patients (pts) diagnosed with advanced-stage malignant pleural mesothelioma (MPM) or thymic tumors (TT) underwent genomic analysis using FoundationOne CDx on FFPE samples. If unavailable, FoundationOne Liquid CDx was used on newly obtained plasma specimens. Molecular tumor boards (MTB) then reviewed the patients’ molecular and clinical data to recommend potential treatments based on biomarkers, including options for clinical trials.
Of the 102 pts from 8 countries enrolled from July 2019 to May 2022, 56 had MPM, and 46 had TT (split evenly between thymomas and thymic carcinomas). One-third were female (21% MPM, 54% TT), with a median diagnosis age of 70 (IQR 55-74). About 29% initially pursued curative treatments (9% MPM, 54% TT). Genomic profiling was conducted on 70 FFPE samples (42 MPM, 28 TT) and 32 cfDNA samples (14 MPM, 18 TT) with a median processing time of 8 days. Significant molecular changes were identified in 64 out of 102 pts (63%; 77% MPM, 46% TT), especially in 49 of the 70 FFPE samples (70%; 88% MPM and 32% TT) and 15 of the 32 plasma samples (47%; 43% MPM and 50% TT).
The most commonly mutated genes included CDKN2A/B and BAP1 in MPM and TP53, CDKN2A/B, and SETD2 in TT. Tumor mutational burden was generally low, with only 2 tumors indicating MSI-high status. MTB recommended potential treatments for 39 instances (17 MPM, 22 TT), including 8 non-biomarker-driven trials, and suggested genetic or hematologic counseling for 7 pts, primarily due to the discovery of hereditary mutations in BAP1 or clonal hematopoiesis.
Pertinent genomic changes were discovered in 63% of the rare thoracic tumors studied, this expanded treatment possibilities for roughly 30% of pts based on MTB’s advice. cfDNA analyses proved useful in cases where tumor samples were insufficient. For these pts, molecular examination and medication availability should be enhanced.
Clinical Trial: https://classic.clinicaltrials.gov/ct2/show/NCT02834884
Tagliamento, M., Morfouace, M., Loizides, C., Oliveira, J., Greiller, L., Raimbourg, J., Toffart, A.C., Chatelier, T., Cloarec, N., Sullivan, I., Brasiuniene, B., Peron, J., Oselin, K., Robert, M., Fernandes, C., Poncin, A., Blay, J., Besse, B., Girard, N. 190P – EORTC-SPECTA Arcagen project: Results of the prospective rare thoracic tumors cohort. Journal of Thoracic Oncology (2023) 18 (4S): S137-S148.
