Danna Reeve, wife of “Superman” actor Christopher Reeve, said she never puffed a cigarette her entire life. Yet, last March 8, the 44-year-old American actress and singer died of lung cancer.
Although it was unlikely that a non-smoker like her would be inflicted with such a disease, Danna was just one of the increasing number of non-smokers who suffer lung diseases. As claimed by American Cancer Society, 10 per cent of males and 20 per cent of females in America who have lung cancer do not smoke.
According to Dr. Ronilla Santos of the UST Hospital Center for Respiratory Medicine, apart from smoking, which accounts for 20 per cent of lung cancer causes, exposure to second-hand smoke—smoke exhaled by a non-smoker—doubles the risk of lung cancer.
“What makes passive smoking more risky than active smoking is that they are not filtered and are directly inhaled by the person,” Santos told the Varsitarian.
Santos said cancer-causing substances present in tobacco smoke, when directly inhaled, immediately accumulate and damage the lung’s tissue lining. The damaged cells may then develop into tumors.
Among the 300 to 400 substances present in every cigarette stick, tar and hydrocarbons cause cancer. Nicotine, on the other hand, which is the addictive substance, does not trigger the disease.
Other than passive smoking, heredity, pulmonary diseases, air pollution, and exposure to radiation can also cause lung cancer among non-smokers. Genetic disorders in families having a history of cancer could also manifest through lung cancer.
“If a person’s father died of lung cancer, he or she has a high risk of having it,” Santos said. “If a person has a twin who had the disease, the other twin has a 50-per-cent chance of having it also.”
Santos said the gene seems to have a “lock-and-key” mechanism. Thus, the disease would develop if a person who has genetic disorder would be exposed to a cancer-causing environment.
Exposure to outdoor and indoor air pollution is another risk factor. In countries like China, where air pollution is high, there are also high incidents of lung malignance, Santos said.
Even banked dirt in the household like radon, a byproduct of radioactive uranium decay, a colorless and odorless gas, used to power electrical substations can also cause cancer.
“Radon in these electrical substations leak and sneaks through the subsoil,” Santos said. “People residing near the substations are therefore more exposed to these substances and would most likely develop lung and blood cancers.”
Other than radon, chromium, nickel, and asbestos increase the risk of lung cancer among shipyard workers and miners.
Previous pulmonary diseases such as tuberculosis and chronic bronchitis, which are directly related to smoking, could also trigger lung cancer.
According to Santos, every type of lung cancer has its own histological type, the type of tissue detected in the microscope. If doctors would examine Reeve’s tissues, she would most probably be diagnosed with adenocarcinoma, a tumor originating in the epithelial cells of glandular tissue. This occurs in five to eight out of 10 women, mostly non-smokers.
Statistics from the Department of Health showed there were around 6,500 Filipinos diagnosed to have lung cancer in 2000. Region IV ranked first with 1,255 lung cancer cases, followed by the National Capital Region with 1,255 lung cancer patients.
Another study of the American College of Chest Physicians published in 2002 showed that lung cancer had accounted for 29 per cent of cancer deaths among women in America. Moreover, the frequency of lung cancer cases among women had increased four times, surpassing breast cancer as the top cause of cancer-related deaths among women since the 1930s. This trend is expected to continue until 2010. Marlene H. Elmenzo and Laurence John R. Morales
