The human body is made up of billions of tiny building blocks called cells. Sometimes, cells reproduce in an uncontrolled way and grow into a lump, or tumour.
There are two kinds of tumours: noncancerous (benign) and cancerous (malignant). Benign tumours do not spread to other parts of the body and are not life threatening (except in very rare situations).
Cancerous tumours can attack nearby cells and destroy them. Cancer cells can also get into body fluids and spread to other parts of the body. This is called a secondary cancer or metastasis. Blood and lymph are the fluids which transport cancer cells to other parts of the body. Lymph is a nearly clear fluid that travels through lymph vessels and small oval structures called lymph nodes. Lymph fluid eventually mixes with blood which travels throughout the body.
Cancer is not a single disease with one cause and one type of treatment. There are more than 200 different types of cancer. Each has its own natural course of development and response to treatment.
- If you’re over 40, get an annual check for prostate cancer!
- NZ men live on average 4 years less than women
- 6 out of 10 New Zealand males are overweight
- Nearly a quarter of New Zealand men smoke
- 27% of men have potentially hazardous drinking patterns
- Men have fewer years free from disability and poor health (Health and Independence Report 2005, MOH).
Cancer of the Prostate
In New Zealand, prostate cancer is the most common cancer in men, around 3,000 registrations each year and about 600 deaths from prostate cancer each year (based on the statistics from the Ministry of Health 2007 – 2009 which show an average of 3082 registrations and 602 deaths).
Men who develop prostate cancer are mostly over the age of 65. It rarely occurs in men younger than 55. About one in 13 men will develop prostate cancer before the age of 75. In very elderly men, prostate cancer often grows very slowly and may cause no symptoms.
Some men are more at risk of getting prostate cancer than others, but the most important risk factor is ageing. Men with a family history of prostate cancer have a higher risk; that is, if the father, an uncle or a brother has had prostate cancer.
Doctors do not know what causes prostate cancer. They do know, however, that the growth of cancer cells in the prostate is stimulated by male hormones, especially testosterone. Most prostate cancer growth is influenced by testosterone.
The speed at which prostate cancer grows varies from man to man. In some men the cancer grows very slowly; in other men, it grows more rapidly.
A cancer is often very hard to find when it is located only within the prostate. This is because it may not cause symptoms and may be too small for a doctor to feel during a routine rectal exam.
A man with slow growing prostate cancer may live for many years and die of other causes, without ever having symptoms of prostate cancer. If the cancer grows too much, however, the prostate usually squeezes the urethra, which it surrounds. Symptoms may then start, such as difficulty in passing urine. As the same symptoms can be caused by other problems, difficulty in passing urine does not always mean that prostate cancer is present.
A growing cancer can affect cells close to the prostate. At the same time, cancer cells may get into the blood and spread to other parts of the body, especially the bones. A man may not have any symptoms during the early period of cancer spread.
Prostate cancer tends to spread to lymph nodes, bones (especially ribs and bones around the hip and lower back), liver and lungs. Cancer cells that have spread to other parts of the body will grow, causing symptoms such as bone pain, one of the most common problems.