The gist: Oncologists can sometimes look for certain genetic mutations in a patient’s tumor to help determine the best treatment options for that patient. Researchers have recently found that a particular mutation called ROS1 fusion is present in a subgroup of patients consisting of young East Asian patients with lung adenocarcinoma. People with ROS1 mutations in their lung tumors might benefit from treatment with a drug called crizotinib. The drug has not yet been approved for widespread use by the U.S. Food and Drug Administration (FDA), but patients can enroll in clinical trials to gain access to it.
“ROS1 fusion genes were successfully detected independent of gender or smoking history in young East Asian patients with lung adenocarcinoma, a histological subgroup in non-small cell lung cancer (NSCLC), using multiplex reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC) diagnostic tests.
“In NSCLC treatment algorithms, a personalized therapy approach is now being taken based on the genetic characteristics of the cancer. Patients with specific oncogenic molecular aberrations, for example EGFR mutations and ALK gene fusions, respond well to drugs that target these molecular abnormalities. ROS1 is another potential oncogenic molecular driver and this target is sensitive to crizotinib, a drug approved for the treatment of ALK gene fusion NSCLC patients.
“Researchers from the National Taiwan University Hospital examined 160 surgical specimens from early-stage lung adenocarcinoma and 332 specimens of fluid around the lungs (malignant pleural effusions) from late-stage lung adenocarcinoma patients. They initially examined these specimens for EGFR and KRAS mutations as well as ALK gene. Specimens that were negative for these three oncogenic drivers were then examined for ROS1 fusions using RT-PCR and IHC. Fluorescence in situ hybridization (FISH) was used if there was a discrepancy between RT-PCR and IHC.”