mohmmed2007's Blog

Hormones

Most breast cancer is sensitive to the female hormone oestrogen. Sensitive cancer cells need oestrogen to stay alive and removal of oestrogen from the body or stopping any circulating oestrogen getting to the cancer cells is very effective at controlling or killing hormone-sensitive breast cancers. It is possible to determine whether a tumour is sensitive to hormones by performing a chemical test on the tumour.

Tumours can be classified into oestrogen sensitive and oestrogen insensitive tumours.

In premenopausal women who are still having regular menstrual periods, about half of all breast cancers are hormone sensitive. Over two thirds of tumours in postmenopausal women whose periods have stopped are oestrogen sensitive.

The most commonly used medicine against oestrogen sensitive tumours is tamoxifen (eg Nolvadex D). This medicine is an anti-oestrogen in its effect on breast cancers and works by stopping oestrogen getting to the cancer cells. It appears to be a very safe medicine but can cause side effects which can be distressing and these include flushing (similar to those women experience during the menopause), vaginal dryness and vaginal discharge.

Many women complain of weight gain on tamoxifen, but, in randomised studies, women taking tamoxifen put on a similar amount of weight to those women who were not receiving drug treatment. There is an increased incidence of eye problems and disturbance of vision. This is reversible if the medicine is stopped.

The most serious possible side effects of tamoxifen are that it can slightly increase the incidence of cancer of the lining of the womb, and slightly increase the risk of a blood clot in the leg (deep vein thrombosis). However the risks of both these side effects are very low. Tamoxifen has been widely used throughout the world and is a very safe medicine for pre and postmenopausal women. Few women have to stop the medicine because of side effects. Women who have had surgery for early breast cancer are commonly given tamoxifen following the surgery to reduce the risk of recurrence of the cancer.

The production of oestrogen in postmenopausal women requires an enzyme called aromatase. A new class of medicines for treating breast cancers blocks this aromatase enzyme. These medicines are called aromatase inhibitors and include letrozole (Femara), anastrazole (Arimidex) and exemestane (Aromasin). They are very effective in postmenopausal women with oestrogen sensitive tunours. The side effects include flushings, nausea and lack of appetite. Occasionally, women have to stop the medicine because of the constant feeling of sickness.

In premenopausal women the major source of oestrogen is the ovaries. Either removing the ovaries or using an injectable medicine called goserelin (Zoladex), which stops the ovaries from producing oestrogen are effective treatments in hormone sensitive breast cancer. The medicine which stops the ovaries working has to be injected once a month. Side effects of this type of medicine or removal of the ovaries include the rapid onset of menopausal symptoms.

Chemotherapy

Chemotherapy involves being given a combination of anti-cancer medicines, often up to three at a time. The prime target for such medicines is cancer cells that are actively growing and dividing. Unfortunately, anticancer medicines are not able to recognise cancer cells specifically and they also kill normally dividing cells such as the blood and hair cells. The art of the science behind successful cancer chemotherapy is combining medicines which are chosen to minimise the damage to blood cells while maximising damage to cancer cells.

Chemotherapy may be preferable for more advanced cancer that is not hormone responsive and for aggressive disease, particularly if the cancer has spread to other sites, such as the liver. It is sometimes administered prior to surgery in order to shrink a tumour. As outlined above, this sometimes means that the surgeon is able to perform less extensive surgery in patients whose cancers respond.

Cancer chemotherapy is usually given through an intravenous drip in the hand or arm on an outpatient basis. Treatments vary but each session usually lasts between one and two hours and is repeated every three weeks. Patients may be frightened because they have heard about very unpleasant side effects such as nausea, vomiting and hair loss. In fact, by no means everyone will experience all or even any of these problems. Some of the anti-cancer drugs that are in common use cause little or no hair thinning and anti-sickness medicine given with the chemotherapy works well.

A common complaint in people receiving chemotherapy is of weight gain. This is due to the anti-sickness pills which are taken after the chemotherapy. Once the chemotherapy is finished, providing the patient remains active, they should return to their initial weight. One of the less well-known side effects of chemotherapy is to cause premature menopause. This means that periods are likely to stop at a much earlier age if you have had this type of treatment. Bringing forward the menopause is particularly likely to occur in women in their late 30s and 40s, but even younger women can find that their periods temporarily stop during chemotherapy.

Treatment for locally advanced breast cancer

Some patients whose cancer is locally advanced because it has grown directly into the skin overlying the breast are suitable for surgery and are treated in an identical way to patients with early or operable breast cancer. The majority of patients with locally advanced breast cancer are treated with drug therapy followed by surgery and/or radiotherapy. Some patients with locally advanced breast cancer are treated by radiotherapy initially which can be followed by drug therapy and/or surgery.

Drug therapy can consist of either hormonal therapy in slower growing hormone sensitive cancers or chemotherapy in hormone sensitive or more rapidly growing cancers.

Outlook for patients with operable or early breast cancer

There are various factors which relate to survival in breast cancer.

These include:

· tumour size - the smaller the tumour the more likely a patient is to survive.

Surgery

Surgery can be an excision of the tumour with surrounding normal breast tissue (breast conservation) or removal of the whole breast (mastectomy). Clinical trials comparing mastectomy and breast conservation have shown that the two produce identical results.

If the lump is relatively small it is usually possible for the surgeon to remove it along with a small amount of surrounding normal tissue. This is called lumpectomy, wide local excision or breast-conserving surgery.

With a larger lump, this breast-conserving operation may not be possible because so much of the breast tissue would have been taken away that it would badly distort the breast.

Once the lump and surrounding tissue is removed it needs to be examined under the microscope. In some women, the surrounding tissue is abnormal and a further operation is necessary.

A mastectomy (removal of the whole breast) may be necessary if:

· the cancer is too large to remove and leave a reasonable looking breast after surgery.