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What is cancer

What is cancer

Cancer is a disease of the body’s cells. Normally, the cells multiply in an orderly way, allowing your body to grow and to heal after an Injury. Occasionally some cells behave in an abnormal way leading to uncontrolled replication and interaction. They may grow into a lump which is called a tumour.

Tumours can be benign (not a cancer) or malignant (a cancer). Benign tumours do not spread to other parts of the body.

A malignant tumour is made up of cancer cells. If these cells are not treated, they may spread into areas nearby. Multiple spread & multiorgan failure lead to death.

Sometimes c ells break away from the original (primary) cancer and spread to other organs. When these cells reach a new part of the body they may form another cancer. This is called a secondary cancer or metastasis. For example, if breast cancer spreads to the bones, it is called a bone secondary. It is not bone cancer which is a separate disease. The word “cancer” can also be used when cells multiply abnormally but don’t form a lump or tumour. This happens when the blood forming cells are affected producing diseases known as leukaemias.

Treating cancer

Treatment of cancer depends upon the type of cancer you have, where it began and whether it has spread. It may also depend upon factors such as your age. Most cancers are treated by surgery, radiotherapy (X-ray treatment) or chemotherapy. One or more of these treatments may be used.

What is chemotherapy?

Chemotherapy is the use of special drugs to treat cancer by killing cancer cells. Chemotherapy drugs work by interfering with the ability of a cancer cell to divide and reproduce itself. The affected cells become damaged and eventually die. As the drugs are carried in the blood, they too reach cancer cells all over the body.

The drugs damage the cancer cells in different ways. If a combination of drugs is used, each drug is chosen because of its different effects. Unfortunately, chemotherapy drugs can also affect normal cells in your body, sometimes causing unpleasant side effects. Unlike cancer cells, however, normal cells quickly regrow, so any damage to them is usually temporary and therefore most side effects will disappear once the treatment is over.

In most chemotherapy treatment a number of drugs are given at the same time. Sometimes only one drug is used.

Why is chemotherapy used?

The aim of chemotherapy may be to cure or control cancer or to relieve its symptoms of treatments and their frequency will depend upon the type of cancer and the actual drugs used. In general, chemotherapy is given over a period of six to twelve months. However, it may be given for shorter or longer periods. You should discuss your own treatment with your doctor.

How does chemotherapy work?

The chemotherapy drugs must enter your bloodstream in order to reach cancer cells anywhere in your body. The drugs enter your bloodstream immediately if they are injected into a vein or artery. If they are given in another way, they must be absorbed into the bloodstream (e.g. drugs given in tablet form are absorbed from the lining of the stomach or gut).

The chemotherapy drugs travel around your body and can enter and destroy certain cells. The cells most affected by chemotherapy are those which multiply rapidly, such as cancer cells. The rate at which cancer cells are destroyed varies with each type of cancer.

Some normal cells which also multiply rapidly may be affected by chemotherapy but normal cells are better able to renew themselves than cancer cells.

The rest periods between chemotherapy treatments allow your normal cells to recover before the next treatment.

Your doctor will take several factors into consideration when planning your treatment. The most important of these are the type of cancer you have, where in the body it is situated and how far it has spread. Other factors include your age and general health.

The frequency of your treatment and the length of time it takes will depend on several factors including: the type of cancer you have, the drugs you are taking, the response of the cancer cells to the drugs and any side effects the drugs may cause.

Chemotherapy is usually given as several courses of treatment. Depending on the drug or drugs given, each course can last from a few hours to a few days. The total number of courses you have will depend on how well your cancer is responding to the drugs. It may take several months to complete all the chemotherapy courses needed.Some patients on oral chemotherapy take smaller doses daily for several weeks or months before they have a rest period.

It may be necessary for you to have blood test or X-rays or to see the doctor before you are given your chemotherapy and this will obviously take time. All chemotherapy drugs are prepared in a special way and you may have to wait while the hospital pharmacy department prepares them to dispense to you. To help to pass the time it may be helpful to take a book, newspaper, crosswords or perhaps some letters to write.

Changes in the treatment plan

Your doctor will be assessing regularly the outcomes of the chemotherapy courses. In order to do this you may need frequent blood tests, X-rays and scans. The results from these tests show the doctor how much the cancer has reduced in size in response to the treatment. Sometimes, depending on the results of the tests, your treatment plan may need to be modified in some way or even changed completely. Sometimes this is because the present drugs you are having are not shrinking the cancer during treatment. If nausea is likely, you will be given anti-nausea tablets to take at home. These are best taken regularly. You may be advised to take a tablet at home before your next treatment. Ask your doctor, nurse or pharmacist how you should take your prescribed medicines.

Bowel problems

Some people have problems with constipation or diarrhoea. Drinking more fluid can help both these problems.

Constipation may be avoided if you eat more high fibre foods such as wholegrain bread and pasta, bran, fruit and vegetables.

To reduce diarrhoea, you should eat small frequent snacks rather than big meals. Try eating warm or cool foods rather than having things which are hot or icy cold. Avoid spicy foods, coarse whole-grain products, fatty or fried foods, rich gravies and sauces, sausages and raw fruit or vegetables with skins or seeds. Suitable snacks might be clear broth and toast, biscuits and cheese, or cooked rice. After the diarrhoea has cleared up, it is important for you to return to a balanced diet which includes fresh fruits, vegetables and wholegrain cereals. You should report any problems with diarrhoea, constipation or abdominal pain to your doctor.

Mouth problems

Some anti-cancer drugs can affect the lining of the mouth and occasionally cause mouth ulcers or infections. Some people are more likely to have problems than others. Good mouth care is important for everyone having chemotherapy. Use a soft toothbrush to clean your teeth twice each day. You may be given special mouth-washes to try to prevent mouth infections such as thrush. Don’t use commercial mouthwashes without first asking the doctor. Sometimes they can irritate your mouth. A teaspoon of salt in a glass of warm water may help to keep your mouth healthy. If you have a dry mouth it may help to sip fluids, especially water, and to eat moist foods such as casseroles. It may also help you to suck on sour fruit or mint sweets. Discuss any dental problems with your doctor. Before you have any dental treatment tell your dentist that you are having chemotherapy.

Hair loss

Hair loss or thinning is caused by some drugs which temporarily damage the hair. Again, remember that many drugs do not cause hair loss. The degree of hair loss depends upon the drugs used and upon the individual person. When hair loss does occur, it usually starts 2-3 weeks after treatment. Some people lose all their hair very quickly, others lose it after several treatments, while others may only lose a little hair or no hair at all.

Although the head hair is most frequently lost. some people also lose some or all of their body hair. Hair loss is not permanent and the hair will regrow either during treatment or after you have completed treatment. If hair loss is expected, get a wig if you want. Some people find it more comfortable to wear a hat or scarf. Remember to protect your head against sunburn or extreme cold. If your eyelashes fall out, wear glasses or sunglasses to protect your eyes on windy days.

Taking care of your hair and scalp.

You should keep your hair and scalp very clean.

Having treatment for cancer can alter the way people feel about themselves and about their special relationships. Some people find that they feel no difference or that the cancer experience draws them even closer to their partner. Other people may be less interested in intimacy and sex or they may feel that intimacy and sex are, temporarily, less important.

The side effects of chemotherapy may mean that you do not feel like having sex because you are too tired or you feel nauseated. Because of body changes, some people may also feel that they are less sexually attractive to their partner.

Sometimes, male patients may not be able to have an erection and female patients may experience some vaginal dryness. These changes are usually temporary and everything returns to normal as you feel better or as you complete your treatment. Sometimes simple measures, like using KY Jelly to relieve vaginal dryness, may be all that are needed.

If you are concerned about changes in your usual lovemaking pattern, it is important that you talk about them with your partner. He or she may be feeling that, if they raise the topic, they might be placing too much of a demand on you or make you feel guilty. Good open communication will do a lot to reassure yourselves of your affection and need for each other.

Although you may not feel like sexual intercourse, there are many other ways in which you and your partner can maintain your closeness and warmth. Touching, cuddling, kissing and stroking can all be both pleasurable and comforting and, as you begin to feel better, you can gradually resume your usual ways of love-making.


Chemotherapy may have a temporary or permanent effect on fertility. Some women have irregular periods; some stop altogether. This may correct itself some time after treatment.

Although the chance of a pregnancy in the future is reduced, some women are still able to have children. In men, chemotherapy may reduce sperm production. This reduction in sperm numbers can range from very mild to very severe (where sperm are no longer made). This effect can be temporary or permanent. Some men may consider having sperm stored before treatment starts thereby permitting artificial insemination at a later date if desired.

Family planning

Despite decreased fertility, it is still possible for pregnancy to occur. Because there is a risk that anti-cancer drugs may affect ova and sperm and hence the unborn baby pregnancy is not advisable either for female patients or for the female partners of male patients. Family planning precautions must he taken. Discuss this with your doctor or nurse if necessary. Should pregnancy occur, discuss it with your doctor as soon as possible.

The ‘Pill’ may be prescribed to some young women, not only as contraceptive but also to help protect the ovaries from the effects of chemotherapy.

Last reviewed : 26 April 2012
Writer : Dr. Gerard Lim Chin Chye
Reviewer : Dr. Sri Wahyu Taher