The relationship between cigarette smoking and lung cancer needs hardly be stressed here except to note that lung cancer can also affect lifelong non smokers. It is also much more common in people living in urban than in rural areas and in countries with cold damp climates, where chronic bronchitis is rife.
Chronic exposure to dust inhalation in many industrial processes particularly in the mining industries, is also a causative factor. Like smoking, lung cancer is predominantly a disease of men, but the incidence in women is rising.
The illness may arise quite suddenly in someone in apparent good health and typically in his fifties, or it may be superimposed insidiously after a long history of chronic bronchitis and emphysema, typically in a patient in his seventies.
The symptoms are often very vague, and sharp weight loss. A common presentation is “pneumonia” that fails to respond to treatment. Very often the first indication of this disease is some metastasis manifestation, such as bone pain from a secondary tumor deposit, hoarseness from compression of the recurrent laryngeal nerve, or headache and irrational behaviour form a brain metastasis.
The diagnosis is usually very obvious on simple chest x-ray and if any doubt remains it can be confirmed by bronchoscopy and biopsy. The only really curative treatment is early and adequate surgery. Each lung consist of several lobes. If the tumor id far out from the main lung root, it is sometimes possible to remove only the affected lobe, with relatively minor residual respiratory impairment.
If the tumor is more centrally situated, it may be possible to treat it by removal of the whole lung. This, of course, results in a 50 percent reduction in respiratory volume, but in time the remaining lung can compensate quite remarkably. If the tumor is more central still, invading the vital structures of the mediastinum, the situation is inoperable.
Unfortunately, the great majority of lung cancer victims are inoperable when first diagnosed, either because of the site of the primary tumor or because metastases are already present. Treatment of these inoperable situations is most unsatisfactory.
Radiotherapy and chemotherapy are often used and, although occasional worthwhile responses are recorded, such benefical responses are the exception to the general rule. The overall cure rates in cancer of the lung are extremely poor, and the survival time from the date of diagnosis until the date of death is usually comparatively short and measurable in onths. Some benefits from ascorbate therapy has been observed.
A cancer of the pleural covering of the lung is known as a mesothelioma. This somewhat rare form of cancer, which can also rise in the peritoneal lining of the abdomen, is usually associated with absestos exposure. It tends to be highly aggressive and to pursue a brisk downhill course. Is is virtually untreatable by any conventional method or therapy.