RADIOTHERAPY (RADIATION THERAPY)

What is radiotherapy?

Radiation therapy (also called radiotherapy or X-ray therapy) uses high powered x-rays or radioactive seeds to kill cancer cells. The aim of radiotherapy is to cure cancer, where possible, whilst maintaining acceptable function and cosmesis. Radiotherapy can be used alone or with chemotherapy or surgery. Where cure is not possible, the aim is the relief of symptoms (palliation) of cancer, thereby improving the person's well-being.

Action of radiotherapy

Radiotherapy works by destroying cells, either directly or by interfering with cell reproduction using high-energy X-rays, electron beams or radioactive isotopes. When a radiated cell attempts to divide and reproduce itself, it fails to do so and dies in the attempt. Normal cells are able to repair the effects of radiotherapy better than are malignant and other abnormal cells. Thus, normal cells are able to recover from exposure to radiation and maintain integrity and viability better than malignant cells.

If the dose and delivery of radiotherapy are well chosen and the disease is localised to the region of treatment, the cancer dies, whereas the normal tissues survive and the patient is made well again. If fewer than all the cancer cells are killed, improvement may only be short lived and the cancer may regrow. Since normal tissues are less able to withstand the effects of further radiotherapy, repeated treatments at a later date are seldom beneficial.


What are the types of radiotherapy?

Types of radiation therapy include:

External beam radiation is the most common form. This method carefully aims high powered x-rays directly at the tumour from outside of the body.
Internal beam radiation uses radioactive seeds that are placed directly into or near the tumour. Internal beam radiation is also called interstitial radiation or brachytherapy.
Radiation during surgery (intraoperative radiation) , which involves external beam radiation focused directly at the area that needs radiation during an operation.
Systemic radiation, which involves a radioactive substance that can be injected into a vein. The substance travels throughout the body, delivering radiation.

What is radiotherapy used for?

Radiotherapy is the principal treatment for various skin cancers; cancers of the mouth, nasal cavity, pharynx and larynx; brain tumours and many gynaecological, lung cancers, and prostate cancers. Radiotherapy plays a leading role in conjunction with surgery and/or chemotherapy in breast cancer, bowel cancer, bladder cancer, Hodgkin's disease, leukaemia and lymphomas, thyroid cancer, childhood cancers, gynaecological and testis tumours, as well as many other cancers and certain benign conditions.

What are the side effects of radiotherapy?

Radiation therapy can have many side effects. These side effects depend on the part of the body receiving radiation, the dose of radiation, and how often the therapy is given. The side effects include:

Hair loss
Pain
Red, burning skin
Shedding of the outer layer of skin (desquamation)
Increased skin colouring (hyperpigmentation)
Death of skin tissue (atrophy)
Itching
Fatigue and malaise
Low blood counts
Difficulty or pain swallowing
Erythema
Oedema
Changes in taste
Anorexia
Nausea
Vomiting
Increased susceptibility to infection
Fetal damage (in a pregnant woman)



- NDTVDOC

Breast Cancer in India

The incidence of breast cancer is rising in every country of the world especially in developing countries such as India. This is because more and more women in India are beginning to work outside their homes which allows the various risk factors of breast cancer to come into play. These include late age at first childbirth, fewer children and shorter duration of breast-feeding. Of these, the first is the most important.

In addition, early age at menarche and late age at menopause add to the risk to some extent. Family history of breast cancer increases the risk as follows: if a woman has a mother who has suffered from breast cancer her risk increases about 3 fold while having a sister with cancer, the risk increases by about 2-3 fold. About 5% of breast cancers are hereditary, i.e. due to a gene being transmitted either from the father or from the mother. Typically, these families have many members who fall victim to the disease, which tends to occur at a relatively young age and often affects both breasts. Two genes namely BRCA1 and BRCA2 have been identified although genetic testing, because of ethical, emotional and social implications that they carry, is still in the sphere of research in most developed countries except the U.S. Thankfully, the incidence of breast cancer is much lower in India compared to western countries. The incidence varies between urban and rural women; the incidence in Mumbai is about 27 new cases per 100,000 women per year while in rural Maharashtra it is only 8 per 100,000. The chances of cure in women who develop the disease is related to early diagnosis.

There are 3 methods for early detection of breast cancer. Mammography i.e. X-ray of the breast, done at regular intervals, say every 2 years, is popular in the west. However, mammography is expensive, technology driven and requires stringent quality control and extensive experience on the part of technicians and doctors involved. If these are not available, mammography can do more harm than good by falsely diagnosing cancer or missing it when it is actually present. I would personally recommend mammography only in women who have a family history of breast cancer or other risk factors. The second method is for a woman to get herself examined clinically be a breast specialist. It appears that if clinical examination is done properly it may be as effective as mammography. The third method is self-examination whereby a woman examines her own breasts once a month after taking lessons from an expert. Many women however do not like doing self-examination often out of fear of finding cancer.

Nevertheless evidence suggests that if the examination is done properly and regularly, it may help to detect breast cancer early. Typically, breast cancer arises from cells lining the milk ducts and slowly grows into a lump. It is thought that it takes about 10 years for a tumour to become 1 cm in size starting from a single cell. Once breast cancer develops, surgery is the usual treatment. If detected early enough, the breast can be conserved by removal of the lump alone without a mastectomy. In this case, the glands in the armpit are also removed. This treatment is followed by radiotherapy to the breast. Chemotherapy is usually given as an adjunct to surgery to kill any stray cells that might have escaped and lodged elsewhere. Anti-oestrogen drugs are also used very effectively in women whose tumours are responsive to hormones. The latter is determined by a laboratory test called oestrogen receptor test. Sometimes chemotherapy is given first to reduce the size of the tumour so that breast conserving surgery can be performed. Once breast cancer spreads to other organs the disease usually becomes incurable and the treatment is directed at relieving symptoms, if any. Nevertheless, much can be achieved with treatment by anti-hormone medications as well as chemotherapy and radiotherapy. Many young women experience pain in their breasts, especially before their periods. Pain in the breast is usually not related to cancer and often settles down on its own. If severe, painkillers can be taken. Pain in the breast is rare after menopause.

Many women have lumpy breasts which in medical jargon is called “fibroadenosis”. This again is not a precursor of cancer. Lumps in the breast in premenopausal women may sometime be caused by cysts containing fluid. This can be aspirated with a needle which usually cures the condition. Younger women sometimes have solid non-cancerous lumps called “fibroadenoma” which usually requires removal under local anaesthesia. Discharge from the nipple is not uncommon, but if it is bloody, this may sometimes indicate the presence of early cancer. To conclude, do not ignore a lump in the breast – see a doctor.

- Prof Indraneel Mittra
Senior Consultant Surgeon,
Tata Memorial Hospital,Mumbai
NDTVDOCTOR

Green tea lowers blood cancer risk

Drinking about 5 cups of green tea a day may lower your risk of developing certain blood cancers.

Drinking green tea has been associated with lower risk of dying and heart disease deaths. Several biologic studies have reported that green tea constituents have anti tumor effects on hematologic malignancies. However, the effects in humans are uncertain. To explore the association between green tea consumption and risk of blood cancer, researchers identified 19,749 men and 22,012 women from Japan, aged between 40 and 80 years, with no previous history of cancer. The researchers gathered information on the diets and green tea drinking habits of participants and followed them for development of blood and lymphoid system (a major component of the body's immune system) cancers. The researchers also took into consideration factors like age, gender, education, smoking status and history, alcohol use, and fish and soybean consumption.

During 9 years of follow up, 157 blood, bone marrow, and lymph system cancers developed in the study group. It was found that the overall risk for blood cancers was 42 percent lower among study participants who drank 5 or more, versus 1 or fewer, cups of green tea daily. Drinking 5 or more cups of green tea daily was also associated with 48 percent lower risk for lymphoid system cancers.

The researchers also observed reduced risk for blood-related cancers among obese study participants, who are considered to have higher risk of these cancers.

Further studies are needed to confirm the health benefits of drinking green tea, and to determine whether daily consumption might prevent certain other cancers.

- article from NDTVDOC