Nonsmokers Get Lung Cancer, Too
About 17 percent of lung cancer cases diagnosed in American females each year occur in women who have never smoked.
As part of a multicenter national clinical trial, researchers at the Ohio State University Comprehensive Cancer Center are working to learn why and how best to treat these cancer patients.
"Lung cancer in people who have never smoked is now considered a distinctly different disease from lung cancer in smokers," says Dr. Gregory Otterson, a researcher at the Comprehensive Cancer Center and a medical oncologist at the James Cancer Hospital and Solove Research Institute at Ohio State University who specializes in treating lung cancer. "This second form of lung cancer may arise from the same cell of origin, and it looks the same under the microscope, but we treat it very differently now."
Lung cancer is the leading cause of cancer deaths in the United States, accounting for about 29 percent of all cancer deaths annually. More than 200,000 new cases of the disease are expected this year, along with more than 160,000 deaths, according to the American Cancer Society. Each year, an estimated 20,000 lung cancer deaths occur among men and women who are lifelong nonsmokers, Otterson says.
"If lung cancer among never smokers were considered a completely separate disease, it would affect be the sixth or seventh most frequent cause of cancer," he says.
During the past decade, researchers have begun studying the subtle differences found in the tumors of smokers and those who have never smoked.
"The carcinogens found in cigarette smoke cause certain genetic mutations, and it turns out that the never-smoking population has very different genetic changes, suggesting that never-smoking lung cancer is a distinct disease from lung cancer seen in smokers," Otterson says. "More studies are needed to determine the cause."
Otterson is enrolling patients in several clinical trials using the drug erlotinib with and without chemotherapy to treat lung cancer patients who have never smoked.
Erlotinib, which is also used to treat non-small cell lung cancer and pancreatic cancer, is a molecularly targeted agent designed to inhibit the epidermal growth factor receptor, which is commonly present at abnormally high levels in breast, colon and lung cancers.
While erlotinib is effective in smokers and ex-smokers with lung cancer, it appears to be particularly effective in never-smokers with lung cancer. The ongoing studies examine how best to incorporate this agent with other drugs.
"We need to fight this disease with all of our resources," Otterson says. "Right now, we lack an effective screening tool, as we do for lung cancer in smokers. Often by the time patients seek medical help, their lung cancer is advanced."
Symptoms of lung cancer may include persistent coughing, chest pain, shortness of breath, coughing up blood, persistent weight loss and fatigue, Otterson says.