Usually, but not always, the first line of treatment is some form of surgery and this is usually done by the consultant surgeon. There may be two types of surgery, i.e. radical surgery or palliative surgery. Radical surgery involves the complete surgical removal of the tumour and some surrounding tissue, and the draining lymph nodes. The aim is to remove all of the cancerous growth before it spreads to other sites of the body and to cure the patient. With palliative surgery, conducted when the complete removal of the tumour may not be possible, only limited surgery is done to relieve symptoms. Following surgery the patient is then referred to the oncologist to decide if any further treatments are required.
One of the treatments that may be offered is chemotherapy. Chemotherapy is the delivery of anti-cancer drugs into the patient. It is a systemic form of treatment which means it has the ability to kill cancer cells throughout the body. Chemotherapy is usually delivered intravenously through the veins but a small number of chemotherapy drugs are given orally.
Chemotherapy drugs are usually given in combinations of two to three drugs, known as regimens. There are many regimens used for different cancers and they are usually delivered in cycles. The frequency between different cycles will vary with different regimens and can be from one to four weeks. The interval between cycles allows the body to recover from the effects of chemotherapy.
Chemotherapy drugs are designed to kill fast growing cancer cells. These drugs travel throughout the entire body and can affect other normal fast growing cells. These effects on some of the normal cells are responsible for the side effects of chemotherapy. Some drugs are tougher on the patient whilst some are very easy to tolerate. Some side effects occur commonly whilst some are rarely seen and most are mild, though some can be more severe. The majority are temporary and reversible. The oncologist is usually able to prescribe some medications to prevent or treat some of the effects. Table 1 lists some possible side effects of chemotherapy.
Chemotherapy Side Effects:
Loss of hair
Generalized tiredness and fatigue
Loss of appetite
Nausea and vomiting
Diarrhoea or constipation
Blood effects : low haemoglobin, low white blood cells, and low platelets
Menopause and sterility
The next modality of treatment used in the management of cancer is radiotherapy. Radiotherapy involves the delivery of high energy radiation or X-rays to a specific part of the body with cancer. It is often wrongly referred to as 'laser' or 'current' treatment.
There are also a few types of radiotherapy. Radical radiotherapy is the use of radiotherapy as the main modality of treatment to cure the cancerous tumour, and is usually of high dose, typically daily for a duration of six to eight weeks. Adjuvant radiotherapy is when the radiation treatment is given as an adjunct after the main treatment, usually surgery, to sterilise possible microscopic residual disease in the tumour bed. Palliative radiotherapy is radiation treatment delivered just to relieve the symptoms of advanced and incurable cancer. The radiation treatments itself are painless. The actual treatment takes only a few minutes but the whole session can last 15 to 30 minutes due to the time required to set up the equipment and position the patient.
The side effects of radiotherapy depend on the part of the body receiving the radiation, the radiation dose and the size of the treatment fields. The effects usually manifest after a few weeks of starting the radiation treatment although some side effects may only be seen many years later. Most are temporary and reversible after treatment although some side effects may be permanent. Table 2 lists some of the common side effects:
Side Effects of Radiotherapy:
Generalised lethargy and fatigue
Skin redness & loss of hair in treated area
Sore throat, mouth ulcers, difficulty in swallowing
Loss of appetite
Frequency of passing urine
Dryness of mouth due to poor salivary function
Nerve damage (rare)
Some cancers are dependant on hormones for their growth. In these cancers we can use drugs that block the hormone receptors or reduce the production of the hormones. These drugs may inhibit and slow down the growth of these cancers. An example is the use of Tamoxifen in breast cancer and Zoladex in prostate cancer. Hormonal treatments are generally very safe with little and very tolerable side effects and are usually given long term for many years. The majority are taken orally, although some are given as monthly or three monthly injections.
There are other anti-cancer drug therapies as well, such as immunotherapy treatments used in renal cell (kidney) cancer and melanomas such as the interferons and interleukin 2.
More and more of these newer drugs, which act at the molecular level are being discovered everyday.
Therefore in summary, different cancers from various sites and of different stages are treated differently, with different combinations of the various modalities. Future articles will focus on the specific management of the various cancers and will highlight the roles of the various treatment modalities in each type of cancer.
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By Dr Ahmad Kamal Mohamed