What causes Cancer?
It is often impossible to tell what causes a specific cancer in a specific person. People can lead an addiction-free and healthy life and still develop cancer, usually because a body cell randomly becomes immortal. Cancer is very rarely due to factors inherited from one’s parents.
However, there are some things that are known to cause cancer. Using tobacco (smoking or chewing) is the commonest cause of cancer worldwide. Tobacco causes cancer of the lung, mouth, neck, stomach, oesophagus (food pipe) and other organs. Before the widespread use of tobacco, such cancers were very rare. In the West, where governments have taken action to reduce tobacco use, lung cancer rates are falling. In the developing world, however, where cigarette consumption is actively promoted, lung cancer rates are steadily rising. This is a man-made global health catastrophe.
In India and East Asia, where chewing betel nut (sopari) or tobacco in paan is popular, rates of cancer of the mouth are very high. This is because sopari and tobacco and some pastes used in making paan cause cancer. Other well recognized causes of cancer include regular intake of alcohol in excess. This causes cancer of the mouth, oesophagus (food pipe) and stomach. A diet rich in red meat is also known to cause colon cancer in some cases. Recently, obesity has been identified as a major risk factor in developing cancer. The modern lifestyle causes obesity in many people. It has only recently been identified that body fat is an active organ, and too much of it, combined with a lack of exercise increases cancer rates. Again, this is an example of an entirely preventable cause of cancer.
There is no good evidence to show that stress, emotional problems, mobile phone use or ‘curses’ cause cancer.
How can I prevent Cancer?
The risk of developing cancer can never be reduced to zero. This is because even by leading a healthy and risk-free lifestyle, cell errors will occur by chance alone over a long period of time. So, using the car analogy, even, if a person looks after their car carefully for many years, it may still break down. However, the risk of cancer can be massively cut by simple measures.
Trying to remain fit and healthy is by far the best way to prevent cancer. Specifically for our Indian community, remaining active and not becoming overweight is important. Not smoking and not taking tobacco are critically important in preventing cancer. Not drinking alcohol and not eating red meat will also help reduce the risk of cancer.
There has been a lot of research into whether taking nutritional supplements such as vitamins, herbs or antioxidants reduce cancer risk. None of these have been shown to work, and in fact some have been shown to harm patients.
How do I know if I might have Cancer?
Cancer is often difficult to detect until it has spread (as it is initially small and does not cause any symptoms), and by then it is usually too late to be cured. Some cancers in their early stages can be felt either as a lump (e.g. breast cancer) or, in the case of skin cancer, a mole that changes shape, becomes itchy or starts to bleed. Lumps should always be brought to a doctor’s attention. Some cancers cause specific symptoms. So, colon cancer causes bowel habit change: patients notice that they used to be regular, and now are irregular. Lung cancer can cause shoulder pain or recurrent chest infections. When cancer has spread, patients often feel run down, lose weight or develop night sweats.
How is Cancer Diagnosed?
Cancer is diagnosed by taking a sample of the lump (biopsy) and looking at it under the microscope. Before that, however, patients will undergo some sort of scan to see where and how big the lump is. So, breast cancer patients will undergo a breast mammogram and breast ultrasound, lung cancer patients might need a bronchoscopy and colon cancer patients may need a colonoscopy. Cancers are usually assessed by CT scan and sometimes special tests. Depending on the cancer, it might take six weeks to make a diagnosis as many tests may be needed.
What is Cancer Screening?
Screening aims to pick up cancer at an early stage, before the patient has any symptoms. This improves the chance of being cured. Asian patients often do not take part in screening programmes and so are at a much higher chance of having cancer diagnosed at a later stage, when it is incurable.
Many countries have screening programmes. In the UK women are invited for regular breast mammograms and cervical smears. There is also a bowel cancer screening programme (a stool sample is tested). The role of blood testing to detect prostate cancer is controversial.