Cancer

G

Chemicals

Certain occupations carry an increased risk of cancer because workers are exposed to hazardous substances such as chemicals, asbestos, or radiation. It is therefore very important for work safety procedures to be put in place, to provide as much protection for workers as possible, and for workers to follow the guidelines.

H

Hereditary Factors

It is estimated that 5 to 10 per cent of cancers are inherited, and extensive research is being done to find the faulty genes responsible. Some of these genes have already been found; for instance, the genes BRCA1 and BRCA2 are linked to some hereditary breast cancers. Mutations in BRCA1 are also responsible for about 80 per cent of inherited ovarian cancers. The androgen receptor gene, hAR, and the glutathione s-transferase gene (GST) have both been linked to prostate cancer.

VI

Detection and Diagnosis

A

Symptoms

The earlier a cancer is diagnosed and treated, the greater the chance that it can be cured. Screening is useful for detecting some cancers, but people still need to be aware of symptoms as cancers may occur between screenings. Everyone should also take notice of the early warning signs of cancers for which there is no screening available. The following list of symptoms warrants attention:

• Change in bowel or bladder habits.
• A sore throat that does not heal.
• Unusual bleeding or discharge.
• Thickening or lump in the breast or elsewhere.
• Indigestion or difficulty in swallowing.
• Obvious change in a wart or mole.
• Nagging cough or hoarseness.

Any of these symptoms, indeed any unexplained lump, pain, weight loss, or lethargy, should be referred to a doctor. Although one or more symptoms may be indicative of something other than cancer, a check-up to confirm their cause is the best course of action.

A physical examination for cancer includes inspection and palpation of all accessible sites, especially the skin, neck, breasts, abdomen, testicles, and lymph-node areas. It may include examination of bodily orifices, particularly rectal examination for cancers of the rectum or prostate, and pelvic examination for cancers of the cervix or uterus.

B

Screening and Self-Examination

The earlier a cancer is diagnosed the greater the chance of cure. A monthly check for changes in the way your body looks and feels can help early detection of breast, skin, and testicular cancer. Some cancers can be detected at an early or pre-cancerous stage through screening.

B

1

Cervical Smear

Cervical screening can detect cervical cancer. More importantly, it can prevent this cancer because it detects pre-cancerous cells. The United Kingdom has a national screening programme that invites all women between 25 and 64 to have a cervical smear test every three to five years. Over 80 per cent of eligible women have been screened since the scheme started in 1988. Previously, about 1,900 women died of this cancer annually in the United Kingdom, but there was a dramatic 30 per cent decrease in deaths in the 1990s. Doctors are now considering ways of improving the screening programme—including the possibility of adding a test for HPV-16 to the smear test. It is hoped that the vaccine licensed for use in the United States in 2006 could, in the long term, greatly reduce or remove entirely the need for smear tests.