Pinpointing Primary Tumor Type and Mutations Improves Outcomes - Episode 3
The CancerTYPE ID (CTID) assay consists of a real-time RT-PCR analysis of 92 genes, 87 of which are associated with cancer and 5 that are reference genes. This test is meant to classify the tissue of origin and tumor subtype and has been extensively validated in 12 studies involving more than 4500 tumor samples, states F. Anthony Greco, MD. In one of the validation studies, the CTID test was found to be 90% accurate in patients with known cancers.A prospective study conducted by Greco and his colleagues evaluated approximately 200 patients with cancer of unknown primary site. CTID was utilized to help determine the type of treatment to administer to these patients. Compared with giving empiric chemotherapy, knowing the tumors’ origins and treating accordingly resulted in a 35% increase in survival, notes Greco.
In another study, patients with tumors without a pathological diagnosis received CTID testing, which was able to identify molecular abnormalities in about 50% of patients with lung cancer, says Suresh S. Ramalingam, MD. Clinicians screened 400 patients whose histological subtypes were unknown and selected 70 patients likely to have lung cancer. Molecular profiling of these patients revealed half of them expressed a driver mutation. Although not every driver mutation can be treated with an approved therapy, knowing the mutation type at least allows patients to enroll into a clinical trial or enables clinicians to focus on an individualized approach for that specific patient, notes Ramalingam.