Cancer of the Lung

Like most forms of cancer, lung cancer is also an expression of uncontrolled growth. It usually arises in smokers as a result of chronic irritation of the lining of the air tubes (bronchi) by the tar, which is transported into the lungs in cigarette smoke on inhalation.

Symptoms

The early diagnosis of lung cancer is influenced by the fact that nearly all lung cancer patients have been cigarette smokers and have had a bad cough or bronchitis for years. A cough is also the major symptom of cancer. Although some smokers believe to have noticed a change in the quality of their cough from a loose one to a more hacking-kind of dry cough a few weeks or months before their lung cancer was discovered, this is by no means a constant or reliable finding. What is a warning sign of cancer, though rarely an early one, is the presence of blood in the spittle causing a streakiness of the saliva with a rusty or even bright red colour.

Chest pains can occur in the form of a dull ache which may or may not be related to coughing. Wheezing or hoarseness are also late symptoms as are repeated episodes of infection such as pneumonia o[ bouts of flu. Generalised symptoms of advanced lung cancer include, a~ in other cancers, fatigue and loss of appetite and weight.

Diagnosis

Since there are no unmistakable early signs of lung cancer, it is essential that all smokers have a chest X-ray at least once a year. Because of the presence of air in the lungs, even a small tumour shows up relatives early.

Once lung cancer is suspected on X-ray, the bronchi are examined with an instrument called the fibre-optic bronchoscope This is a thin flexible tube which can be threaded deep down into the larger branches of the bronchi and which enables the examining specialist to see the inside of the tubes by means of a viewer like a tiny television screen. During the bronchoscopy a bit of the suspicious tissue is usually removed for examination under a microscope.

Another test available is examination of the spittle for malignant cells. This is an adaptation of the popular Pap test which has proved to be of such value in the early diagnosis of cancer of the cervix.

Treatment

The choice of treatment for lung cancer depends on the advancement of the growth. All three routine forms of treatment can be employed. The first, surgery, is rarely applicable because only rarely is the tumour sufficiently localised to make possible complete removal of the growth which may sometimes include removal of the nearby lymph nodes too. In more advanced cases a whole lobe or an entire lung may have to be removed. However, the results are poor.

When surgery is not possible, radiation therapy in the form of super voltage x-rays are used to destroy as much of the cancer as possible, with minimal damage to surrounding normal tissue. Radiation therapy i~ mainly used to improve the quality of life by relieving distressing symptoms.

The third form of treatment, sometimes used in conjunction with surgery or radiotherapy, is chemotherapy which uses drugs to kill cancer cells. How much is given and how often depends on the type of cancer to be treated, the type of anti-cancer drug prescribed, how well the drug is tolerated and how long it takes to respond to it. It is not unusual that drug treatment has to be stopped due to its unpleasant side-effects.

Treatment results in lung cancer are disappointing because in the lungs the tumour can advance silently, beyond a stage where it can either be totally cut away or completely removed by radiation. Regular check-ups are vital because the disease has a habit of recurring, sometimes locally, sometimes at a distant site, most frequently in the brain which seems to be a place favoured by lung metastases.

With such a poor treatment record it is incomprehensible, now that we know the close causal relationship between smoking and lung cancer, that many more people do not decide to stop smoking.