Studying the most common type of lung cancer, researchers have uncovered mutations in a cell-signaling pathway that plays a role in forming tumors. The new knowledge may expand treatments for patients because drugs targeting some of these genetic changes already are available or are in clinical trials.
Reporting July 9 in Nature, investigators from The Cancer Genome Atlas (TCGA), including researchers at Washington University School of Medicine in St. Louis, Harvard Medical School and other institutions, studied tumors from 230 patients with lung adenocarcinoma.
"This is the first time we have had a panoramic look at the genomic landscape of this many lung tumor specimens," said oncologist Ramaswamy Govindan, MD, professor of medicine at Washington University and TCGA lung cancer project co-chair. "These studies reinforce the opinion that lung cancer is a very heterogeneous disease."
Combined with an earlier study of 178 patients with lung squamous cell carcinoma, TCGA researchers now have published genetic data on about 400 lung cancer patients and are working to analyze tumors from 600 more. The investigators included scientists at The Genome Institute at Washington University and other major sequencing centers.
In the new study, among the myriad genetic changes observed in adenocarcinoma, one cell-signaling pathway stood out. About 75 percent of the samples had mutations that overactivated a pathway called RTK/RAS/RAF, known for roles in tumor growth.
"It is remarkable how important the RTK/RAS/RAF pathway appears to be," said Govindan, who treats patients at Siteman Cancer Center at Barnes-Jewish Hospital and Washington University School of Medicine. "Mutations in this particular pathway promote cancer cell proliferation. What is amazing is how many ways this pathway can be activated.
"We also know these tumors are not static," he added. "They evolve. We have to be looking at multiple biopsies ove
|Contact: Julia Evangelou Strait|
Washington University School of Medicine