Lung cancer is the leading cause of cancer deaths in North America, write the researchers in The New England Journal of Medicine.
Most lung cancers (nearly 80%) are non-small cell lung cancers, states a University of Toronto news release.
Tarceva "can prolong survival in patients with non-small cell lung cancer after first-line or second-line chemotherapy," write the researchers. The medication targets a protein found on some cancer cells that helps non-small cell cancers grow.
Tarceva, a pill, is approved as a treatment for patients whose lung cancer has continued to progress despite other treatments, including at least one prior chemotherapy treatment.
"This drug offers a new treatment option to patients at a time in their disease when they have no other options," says Frances Shepherd, MD, in a news release.
"Not only does [Tarceva] help them live longer, but it also improves their physical function, their quality of life, and it improves the symptoms of cough, shortness of breath, and pain," she continues.
Shepherd is the Scott Taylor Chair in Lung Cancer Research and a medical oncologist at Toronto's Princess Margaret Hospital. She is also a professor of medicine at the University of Toronto.
Shepherd's study included 731 people from around the world.
All patients had non-small cell lung cancer that had spread locally or to more distant organs. They had already failed treatment with chemotherapy once or twice.
The researchers gave Tarceva to 488 of the patients. The other 243 patients got a placebo.
Average overall survival was 6.7 months with Tarceva and 4.7 months with the placebo, the researchers report.
The disease did not progress for an average of 2.2 months with Tarceva and 1.8 months with the placebo.
Tarceva targets epidermal growth factor receptors (EGFR), which play a role in cancer cell growth.
"Since EGFR is often found in non-small cell lung cancer cells, it has been the focus of efforts to develop new agents that target the EGFR pathway," write Shepherd and colleagues.
Tarceva is made by OSI Pharmaceuticals. The study was partly supported by a grant from the drug company to the National Cancer Institute of Canada Clinical Trials Group.
Participants' tumors were studied by the University of Toronto's Ming-Sound Tsao, MD, and colleagues in a second study in the journal.
They looked for EGFR mutations. The findings suggest that patients may not first need screening for certain gene mutations.
"Our results suggest that mutational analysis is not necessary to identify patients in whom treatment with EGFR inhibitors is appropriate," the researchers write.
"The presence of an EGFR mutation may increase responsiveness to the [drug] but it is not indicative of a survival benefit," they note.