Importance of Identifying the Primary Tumor Type

Knowing the histology and origin of cancer is integral in determining what tests to order and which treatments to utilize, states Suresh S. Ramalingam, MD. It is difficult to order tests for a patient with cancer of unknown primary site, he notes. Those with colon cancer may receive tests that focus on RAS mutations, while lung cancer of adenocarcinoma or nonsquamous histology may be associated with molecular testing for EGFR and ALK, explains Ramalingam.

The CancerTYPE ID (CTID) assay is useful in making a diagnosis of cancer type in patients with unknown or unclear diagnoses, notes F. Anthony Greco, MD. Site-specific treatment can improve outcomes for many patients, says Greco. There are multiple available treatments for individuals with breast cancer or lung cancer that go beyond empiric therapy. There are several sequential therapies that are useful, but oncologists would not know to use them without a specific diagnosis, says Greco.

CTID analysis requires a minimal amount of tissue sample and can be done with approximately 300 cancer cells, comments Ramalingam. This is beneficial since tissue is scarce by the time these tests are conducted. Results are typically received in 5 to 7 days, adds Greco.