Читать книгу The Cancer Directory - Dr. Daniel Rosy - Страница 87

The only way to diagnose cancer definitively is to test a sample of abnormal cells from the site of the tumour. The usual way of doing this is to obtain a biopsy, or a small tissue sample, under either a local or general anaesthetic, depending on the site of the tumour.

Cancer has no specific symptoms – it depends on where the tumour is, how big it is, which structure it is invading and whether it has spread to other parts of the body. A patient with lung cancer, for example, may have a cough with or without blood or phlegm, or a persistent chest infection that does not respond to antibiotics. The usual symptom of breast cancer is a lump in the breast, although it may well have spread by the time it can be detected this way. If it has spread, then its symptoms will depend on the site of the metastases – in the lungs, it may mimic a lung tumour; in the liver, a liver tumour, and so on.

Because cancer produces so many different types of symptoms which can be mistaken for minor illnesses, there may be a period of several weeks with repeated visits to the GP before the symptoms are taken seriously. The best rule of thumb is that any progressing symptom that does not disappear after two to four weeks should be further investigated. Usually, this involves being referred to a hospital where the investigations can be done rapidly.

If cancer is suspected, there are two important requirements: to do a biopsy to find out exactly what type of cells have gone wrong and, therefore, how best to treat them; and to ‘stage’ the disease to find out how far the disease has spread as this, too, dramatically affects not only the optimal treatment, but also the likely outcome.

The tests to determine the site and stage of the cancer include:

• Biopsy, to study a piece of tissue thought to be cancerous – the definitive way to make the diagnosis

• Blood tests, to check for anaemia, bone-marrow function, liver and kidney function, and search for tumour markers – substances produced by cancer cells and detectable in the blood, thereby alerting doctors to the presence or spread of cancer

• Plain X-rays, to provide information about various parts of the body

• Contrast X-rays, injecting or ingesting a radiopaque substance to increase what can be seen on the X-ray

• CT (computed tomography) scans, to provide detailed information about the structure of various internal organs

• MRI (magnetic resonance imaging), a powerful imaging technique based on magnetic field shifts in the body

• Bone and liver scans, to show areas of dysfunction in the bone and the liver that may be due to the spread of a cancer.