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What causes cancer?

The big ‘C’ is the single most frightening condition that any woman can imagine in her lifetime. Every woman wants to prevent it, and avoid ever having to hear the diagnosis from her doctor. Before you can know how to prevent cancer, you have to know what causes it. Cancer is a complex disease, as it is not a single condition and does not have a simple black-and-white cause. There are many different types of cancer, up to at least 200 types, because they can affect any organ or tissue in the body. Then, each cancer has its own causes – not all are related, and some are very specific.

So as you can see, it’s not as simple as putting the blame on one cause. You need to understand the multifactorial nature of cancer, in order to adopt holistic changes to your lifestyle that will help you reduce the risk of cancer.

The big bad C

Cancer is essentially a disease of the cells, where individual cells become abnormal and multiply out of control. Cancer can occur to any of the cells in the body, as everything in our body, including our organs, bones, muscles, skin and blood, is made up of millions of tiny cells. If cancer occurs in the cells of the skin, then the person has skin cancer; if it is in the cells of the breast, then it is breast cancer. Cancer starts from the genes of one abnormal cell. In a normal cell, there are genes that control how the cell divides and multiplies – a cell becomes abnormal if those genes are damaged or mutated. This causes the cell to start multiplying out of control, to form a cancerous (or malignant) tumour. This tumour may form a lump or a patch of cells that can be seen on a scan.

Every person has a risk of developing cancer, simply because we are made up of cells. There is nothing that can 100 per cent completely prevent cancers from developing because nature cannot be controlled. However, there are certain biological, environmental and lifestyle risk factors that increase the likelihood of cell mutations. These could range from cigarette smoke and asbestos to certain viruses. If you reduce these risk factors in your life, you would contribute towards dramatically diminishing the chances of getting cancer. In other words, don’t give your cells a chance to go bad!

Cancer triggers

We all know that smoking leads to lung cancer. This is because cigarettes and cigarette smoke contain cancer-causing substances which arte carcinogenic like benzenes or ammonia. These carcinogens, which turn cells cancerous, are one of the main causes of cancer among people. The longer the duration and the greater the amount of carcinogens that you are exposed to, the greater is your risk of developing cancer. The most commonly known carcinogens are tobacco smoke (causes cancer of the lung, mouth, throat, oesophagus, bladder and pancrease), asbestos (causes mesothelioma), and radiation from UV rays or radioactive materials.

Certain viruses and bacteria can also lead to cancer. This doesn’t mean that you can “catch” a cancer the same way you catch a viral influenza. What happens is that the virus or the bacteria cause cell mutations that lead to cancer. The hepatitis B and C viruses can increase the risk of liver cancer, while the human papillomavirus (HPV) can lead to abnormalities in the cervical and genital cells that may become cancerous after several years. There are vaccinations for hepatitis B and HPV, so that you can protect yourself from infection. Furthermore, women should have regular Pap smears to pick up any possible HPV infection and treat it early.

One type of bacteria known to play a role in cancer is helicobacter pylori, which infects the stomach lining and eventually leads to inflammation and increased risk of cancer. H. pylori infection can be treated with antibiotics.

Lifestyle factors

Some risk factors for cancer are beyond our control. For instance, age increases the likelihood of cancer, but we cannot stop the hands of time from advancing. You are more likely to develop cancer the older you get, because the mutations in the cells take a long time to develop and turn into cancerous cells. When you are older, your body’s immune system is also weaker and less able to resist destroy abnormal cells or repair them. This is the same reason that certain types of cancer are more likely in people with weakened immune systems, like organ transplant patients who take immunosuppressive medications, people living with HIV and AIDS, or those who have syndromes that affect their immunity.

There has been a lot of debate in recent years about whether your diet and physical activity has an impact on cancer development. Increasingly, scientists are starting to say ‘yes’, as research shows that certain foods have cancer-protective properties, while others can increase the risk of cancer. Fruits and vegetables are rich in vitamins, minerals and antioxidants that strengthen the body’s immune system and protect it from damage caused by age, the food we eat and environmental factors. All the different-coloured fruits and vegetables, such as green broccoli, orange carrots, red cabbage, blue berries and purple eggplant, contain unique compounds that may protect against cancer.

Eating at least five servings of colourful fruits and vegetables, each, every day is the easiest form of defence against cancer and keeps the body generally healthy. Eating too much of high-fat foods is thought to contribute to the risk of cancer, because it is most likely to cause obesity. Along with lack of physical activity and overindulgence in alcohol, obesity has a strong link with certain types of cancers, such as colorectal cancer.

Some of my patients have read emails or heard claims that food additives and artificial sweeteners are carcinogenic. These claims can cause a lot of unnecessary fear in people. All ingredients in our food products are regulated by the Ministry of Health, and these products would not be approved if they were shown to cause cancer. If you are wary, you can reduce your intake of artificial sweeteners and processed foods, so that you consume mostly natural ingredients. However, there is no need to be paranoid, as it would take huge amounts of any substance to cause serious harm – and it is rarely possible for a person to consume so much of any product or ingredient.

Born with cancer?

Some of my patients have asked me whether they have “cancer genes”, because many of their close family members, like their mother, sisters and aunts, have developed cancer. Some people may be born with a genetic mutation in their cells that makes them “genetically predisposed” to developing cancer. However, it doesn’t mean that they will definitely get cancer, just that they are at higher risk because they already have one of several mutations needed for cancer to develop.

One instance of genetic predisposition is the BRCA1 and BRCA2 breast cancer genes, where women who carry one of these genes may be at higher risk of developing breast cancer than women who do not have the gene. These genes can be identified through genetic testing. However, all this talk about genetic predisposition can be misleading. Some women think that just because they have the genes, they are doomed to cancer. Other women think that just because they do not have the genes, they will not get cancer, so they do not have to do breast self-examination or go for regular medical checkups.

Let me use BRCA as an example again. Less than 5% of all breast cancer is due to the mutated BRCA1 or BRCA2 gene – which means at least 95% of breast cancer out there is caused by a multitude of other factors, some of which I have described above. That is the most important take-home message for cancer prevention – there is not one single cause for cancer, but a combination of risk factors and triggers. There are many things that have to happen before cancer can develop – for instance, whether you have the genetic make-up, have been exposed to carcinogens, how you eat and exercise, and the general state of your health, all of which will have to cause several genetic mutations before cancer develops.

The best advice I can give women is to live healthy, think positively and always be in control of managing your health. By reducing all of the risk factors listed above, you are giving your body a fighting chance to keep cancer at bay.

Star newspape. Jun 12, 2011
By Datuk Dr Nor Ashikin Mokhtar