In treating cancer, the aim is to remove the cancerous cells while making sure that the cancer does not reoccur. This can be challenging because even if only one cancerous cell remains after treatment, it has the potential to cause a new tumor.

Different techniques are often used in combination as this can increase the chances of all the cancerous cells being removed. The main techniques are outlined below.

Surgery

If the cancer is detected in its early stages, it may be possible to surgically remove the affected tissue. In some cases, it may be necessary to remove the entire organ, such as the prostate gland (prostatectomy), or breast (mastectomy).

Chemotherapy and radiotherapy may also be used before and after surgery to increase the chances of success.

Chemotherapy

Chemotherapy involves the use of powerful cancer-killing medicines. These medicines damage the DNA of the cancerous cells, interrupting their ability to reproduce.

A combination of different medicines is normally used. Chemotherapy is normally used in combination with radiotherapy and surgery.

The medicines that are used in chemotherapy can sometimes damage healthy tissue, as well as the cancerous tissue and, unfortunately, adverse side effects are common.

Side effects of chemotherapy can include:

• nausea,
• vomiting,
• hair loss, and
• fatigue.

However, the side effects should stop once the treatment has finished. Chemotherapy can also weaken your immune system, making you more vulnerable to infection.

Radiation therapy

Radiation therapy involves using legumes of radiation to damage cancerous cells. As with chemotherapy, the process also damages healthy cells but, unlike the cancerous cells, the healthy cells have the ability to repair themselves.

However, if you have radiotherapy, you may experience side effects while you are waiting for the healthy cells to repair themselves. These include:

• tiredness,
• nausea,
• loss of appetite,
• hair loss,
• sore skin, and
• a lack of interest in sex.

The side effects of radiotherapy can persist for several weeks, or months, after treatment has finished.

Hormonal therapy

The growths of some cancers, such as breast, or prostate cancer, can be slowed by blocking the effects of certain hormones, such as testosterone, or estrogen.

However, blocking the effects of certain hormones can cause related side effects. In women, the possible side effects of blocking the hormone estrogen may include:

• hot flashes and sweats,
• loss of interest in sex,
• nausea and vomiting,
• tiredness,
• aching joints,
• headaches, and
• skin rashes.

In men, the possible side effects of blocking the hormone testosterone mayinclude:

• hot flashes,
• sweating
• tiredness,
• weight gain,
• loss of interest in sex,
• an inability to obtain an erection, and
• swelling of the breasts.

Monoclonal antibody therapy

Monoclonal antibody therapy is a relatively new kind of treatment that was first introduced in the late 1990s. Monoclonal antibodies are antibodies that are genetically engineered in a laboratory. They are designed to directly target and attack cancer cells. This is why monoclonal antibody therapy is sometimes referred to as targeted therapy.

There are several ways that monoclonal antibodies can attack cancerous cells. They can:

• kill the cancerous cells by delivering tiny pellets of radioactive material to them,
• deliver a small amount of chemotherapy medicine directly into the cancerous cells, and
• block the signals in the cancerous cells that cause them to grow and reproduce.

Some types of monoclonal antibody therapy are still considered to be experimental, and will only be used when other treatments have failed. However, some forms of the therapy are now commonly used, such as the medicine Herceptin, which is sometimes used in the treatment of breast cancer.

The medicines that are used in monoclonal antibody therapy are administered directly into the vein (intravenously). Side effects of monoclonal antibody therapy may include:

• nausea,
• skin rashes,
• flu-like symptoms, such as chills, fever, and muscle aches,
• itchy skin, and
• diarrhea.

Monoclonal antibody therapy has been known to cause heart problems in some people, such as heart disease, or heart attack. Therefore, it is likely that you will not be able to receive monoclonal antibody therapy if you have a history of heart disease.

If you do have monoclonal antibody therapy, your heart function will be regularly monitored during your treatment. If monitoring reveals that your heart function is being adversely affected, treatment will have to be stopped.

Rarely, monoclonal antibody therapy can cause severe allergic reactions in some people. This is known as an infusion reaction and can be potentially fatal if left untreated.

Most infusion reactions happen within 24 hours of the first time somebody begins treatment, so it is likely that you will be closely monitored once your treatment begins. If you begin experiencing the symptoms of an infusion reaction, anti-allergy medicines, such as corticosteroids, can be used to relieve symptoms.

Immunotherapy

Immunotherapy is a form of monoclonal antibody therapy that uses the body's immune system to attack the cancerous cells.

Normally, the body does not regard the cancerous cells as a foreign object, so the immune system does not attack them.

However, in immunotherapy, the monoclonal antibodies change the composition of the cancerous cells in such a way that the immune system regards them as a foreign object. It then starts attacking the cells, in the same way that it would normally attack an infection.

The side effects of immunotherapy are the same as the other types of monoclonal antibody therapy (see above).

Angiogenesis inhibitor therapy

Another new type of cancer treatment is angiogenesis inhibitor therapy. In order to grow, tumors need to create new blood vessels - a process known as angiogenesis.

Angiogenesis inhibitors are medicines that block the creation of new blood vessels, slowing the growth of the tumor.

The medicines cannot kill tumors, but have been shown to be effective in treating some forms of cancer when used in combination with chemotherapy and radiotherapy.

Alternative and complementary therapies

A large number of alternative therapies have been suggested for the treatment of cancer, such as homeopathy, vitamin supplements, or special diets. However, there is no clinical evidence that these alternative therapies are effective.

Complementary therapies are designed to complement conventional treatment, but not replace it. A number of complementary therapies have been shown to be of some use in coping with the symptoms and psychological effects of cancer.

Examples of complementary therapies include:

• yoga,
• relaxation techniques, such as mediation,
• hypnotherapy, and
• acupuncture.

A reputable complementary therapist will never make claims that their therapy alone can cure cancer, or try and persuade you to abandon your conventional treatment.