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Archive for May 13th, 2010

Tamoxifen
Tamoxifen is an anti-oestrogen drug that was developed over 30 years ago. It is used widely to treat breast cancer and occasionally some other cancers.

Tamoxifen can also be used to treat or prevent side effects of breast tenderness and swelling in some men with prostate cancer. These side effects can happen as a result of their hormone treatment.

How tamoxifen works
The way in which tamoxifen works is quite complicated and not yet fully understood, but its main function is as an anti-oestrogen drug.

Most breast cancers need supplies of the female hormone oestrogen to grow. Cancer cells have proteins called receptors on their surface that the sex hormones attach to. Cancers with oestrogen-receptors on the surface of their cells are called ‘oestrogen-receptor-positive’ (ER-positive) and tamoxifen is most effective against these cancers.

Under normal circumstances, when oestrogen comes into contact with the receptors, it fits into them and activates the cancer cells to divide so that the tumour grows.

Tamoxifen fits into the oestrogen receptor but does not activate the cells to divide. The tamoxifen stays in place and stops oestrogen from reaching the cancer cells so that they either grow more slowly or stop growing altogether.

Tamoxifen can greatly reduce the chance of oestrogen-receptor-positive cancers coming back after surgery. It can also be used to shrink large tumours before surgery so that they can be removed.

When tamoxifen may be prescribed
Your doctor will consider a number of different factors before they choose the most appropriate treatment for you.

A test may be done to find out whether your breast cancer cells have oestrogen-receptors (ER) and progesterone-receptors (PR). This helps your doctor to decide on treatment, as ER-positive cancers respond well to tamoxifen.

Tamoxifen can be used after surgery for early breast cancer, to reduce the risk of the cancer coming back. This is known as adjuvant therapy. Tamoxifen is the hormonal therapy that is usually used in women who have not been through their menopause.

You may be given tamoxifen for five years. Some women are given tamoxifen for a few years and are then changed to a different type of hormonal therapy known as an aromatase inhibitor. Aromatase inhibitors include anastrozole| (Arimidex®), exemestane| (Aromasin®) and letrozole| (Femara®).

Occasionally tamoxifen is used before surgery|, to shrink a large breast cancer so that a lumpectomy| (removal of the lump) is possible, rather than removal of the whole breast (a mastectomy|).

Tamoxifen can also be used to control a cancer that has come back or has spread to other parts of the body.

Preventative treatment
Research is currently being done to see if tamoxifen can prevent breast cancer in women who have a high risk of developing the disease. ‘High risk’ is defined as having one or more close relatives (mother or sister) who had breast cancer before they were 50. The results of some trials are available, but others are still ongoing. If you think that a member of your family may be at high risk of breast cancer, they should discuss the possible monitoring and treatment options with their doctor.

How tamoxifen is taken
Tamoxifen is taken as a tablet that should be swallowed whole with a glass of water. The tablets come in different strengths: 10mg, 20mg and 40mg. The drug is manufactured under several different brand names and these may appear on the tablets. It is also available as a sugarfree syrup for people who have difficulty swallowing tablets.

Tamoxifen is usually prescribed as a single daily dose and this should be taken at the same time each day. Some women prefer to take the tablet with food as it may make you feel sick and can leave a metallic taste in your mouth. It is best to find a convenient time and stick to it.

Tamoxifen is commonly prescribed for five years. Aromatase inhibitors are sometimes given after two or three years of treatment with tamoxifen.

Possible side effects
Each person’s reaction to any medication is different, and it is impossible to predict who is going to have side effects. Many women who take tamoxifen have no side effects, while others will experience them.

Very rarely, if the side effects are severe, you may have to stop taking tamoxifen and a different drug may be prescribed.

Side effects are more common in premenopausal women, who may develop menopausal side effects as a result of a lowered level of oestrogen. The most common side effects, apart from feeling sick (nausea), are hot flushes and sweats, particularly at night.

Flushes and sweats Sometimes the flushes will gradually lessen over the first few months but some women continue to have them for as long as they take tamoxifen. There are a number of ways to help to reduce or control hot flushes and sweats. Some women find it helpful to avoid or cut down on tea, coffee, nicotine and alcohol.

Some women find that complementary therapies| can help, and your GP can give you details about obtaining these on the NHS. If you find your own complementary therapist, make sure that they are properly qualified and registered.

Sometimes other drugs can be prescribed to reduce hot flushes and sweats. Research suggests that some types of antidepressant drugs may be helpful in controlling this side effect. Your nurse or doctor can discuss this with you.

If you are having troublesome hot flushes you can discuss possible treatments with your doctor. Your doctor may be able to prescribe a different hormonal therapy instead. Sometimes the hot flushes continue for a long time after you have stopped taking tamoxifen.

Nausea and indigestion Feeling sick (nausea)| and indigestion are fairly common but can often be relieved by taking your tablets with food or milk or at night. Although nausea is quite common initially, it usually wears off after a few weeks.

Weight gain Some women notice that they put on weight while taking tamoxifen. This may be due to water retention.

Change in periods Women who have not yet reached the menopause may notice that their monthly periods change – they may become irregular, lighter or sometimes stop altogether. Some women also notice an increase in vaginal discharge and itching of the area around the vagina (the vulva).

Leg cramps Some women get leg cramps with tamoxifen. Walking around may stretch the muscle and help with this. Let your doctor know if leg cramps are a problem. If your leg becomes red, hot or swollen (see blood clots) let your doctor know immediately.

Less common side effects
Back to topDepression, tiredness and dizziness Some women feel depressed while taking tamoxifen, but this may be due to other causes.

Headaches Some people affected by migraine notice a change in the pattern of their headaches.

Blood clots (Thrombosis) In postmenopausal women, tamoxifen can slightly increase the risk of blood clots and strokes. Pain, warmth, swelling or tenderness in an arm or leg (or any chest pain), must be reported to your doctor immediately.

Visual problems Blurred or reduced vision is very rare, but any visual changes should be reported to your doctor.

Voice changes This has been reported by some women. Professional singers may want to seek help and advice from their doctor.

Tumour flare Rarely, women who are prescribed tamoxifen for advanced cancer, where it has spread to the bones, may have tumour flare when they start taking tamoxifen. Tumour flare can cause a raised level of calcium in the blood (hypercalcaemia), with symptoms of nausea, vomiting and thirst. Very occasionally, a short stay in hospital is necessary until the calcium levels have been reduced.

Rare side effects of tamoxifen are mild allergic reactions which may include skin rashes and some hair falling out. This will regrow later.

Long-term side effects
Studies have shown that post-menopausal women who take tamoxifen over a long period of time may have a very slightly increased risk of developing cancer of the lining of the womb (endometrial cancer). However, this small risk is generally outweighed by the benefits of taking Tamoxifen.

If detected early, treatment for endometrial cancer is usually very successful. An early warning sign is abnormal vaginal bleeding, although this is often caused by a non-cancerous condition such as polyps. If you have any abnormal vaginal bleeding you should let your doctor know.

In some cancer hospitals women are given regular gynaecological check-ups to detect early signs of endometrial cancer. An ultrasound scan, using sound waves, may be done to check for signs of change in the womb lining. A small probe is inserted into the vagina and the doctor can look at the scan on a screen. Any changes can be seen straight away. The scan is safe and only takes a few minutes.

For most women the beneficial effects of tamoxifen far outweigh the risks.

Additional information
Contraception Tamoxifen should not be taken during pregnancy as the developing foetus may be harmed. Although it can affect a woman’s periods, tamoxifen is not a contraceptive. It’s important to use an effective, non-hormonal form of contraception during treatment.

Fertility Women who haven’t been through their menopause may still become pregnant when they’ve finished treatment with tamoxifen. Doctors usually advise you to wait for a few months after tamoxifen treatment is over before you try to get pregnant. Talk to your doctor first if you are thinking of getting pregnant.

Risk of blood clots If you have a history of blood clots or deep vein thrombosis (DVT) let your doctor know, as tamoxifen may not be suitable for you.

Interaction with other drugs Tamoxifen can increase the effect of the drug warfarin, which is used to thin the blood in people prone to blood clots. If you are taking warfarin, let your doctor know straight away.

Bone loss Tamoxifen may help to prevent bone loss in women who have been through their menopause. In some women it may reduce the risk of osteoporosis (thinning of the bone).

Heart disease Tamoxifen can lower the level of fat (lipids) in your blood (high) levels of fat contribute to heart disease). But research doesn’t show that tamoxifen reduces the risk of heart disease.

———

As with Chemotherapy a long list of side effects that few of us will ever have.

I was an unlucky one and found Tamoxifen if taken in the morning made me feel sick all day. If I took it at night the ‘Hot Flashes’ kept me awake . Trial and error brought me to taking it at lunch with a banana. Banana is very good for any type of acidity in the stomach. Tamoxifen and I,are now best friends.

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I would like to pause for a moment with my story, to tell you of something I have only discovered today. I have come a long way in the last two years and have learnt a lot.

Not nearly enough though, it would seem.

On my last visit to my Oncologist, who is now a man (I asked to change Oncologists for personal reasons) I discussed with him the early menopause brought on by Chemotherapy. The night sweats or ‘Hot Flashes’ and if there was anything that could be done to ease these symptons. My doctor, a wonderful man and very helpful suggested I try Soy, his wife who is also menopausal found this helped a lot.

I of course, should have asked him if his wife had ever suffered from breast cancer. Soy to a woman like myself ,whose cancer was estrogen positive can increase the risk of cancer returning.

I only found this information out this morning ,thanks to a friend, who is also a breast cancer survivor. I have stopped the Soy and have an appointment with my Oncologist next Wednesday. I will then be able to discuss my concerns with him.I will also post his response.

Meanwhile here are some facts on Soy…

Effect of soy consumption on breast cancer
Researchers have only recently started to investigate the possible effects of soy to breast cancer. More and more women who are adding soy to their diets to help prevent breast cancer but researchers are unsure of the exact effects.

How can soy protect against cancer?
Some animal studies and small human clinical trials have shown that soy foods may offer some protection against breast cancer. Researchers believe that isoflavones may help protect against breast cancer because isoflavones compete with natural estrogen in the body to bind to special estrogen receptors on cells. It is known that estrogen stimulates breast cell growth. Because isoflavones may block estrogen from reaching estrogen receptors, pre-menopausal women who include soy in their diet may decrease their risk of breast cancer.

Effects of soy in post-menopausal women
There’s more uncertainty regarding the effects of soy isoflavones in post-menopausal women. Studies have shown that soy isoflavones may provide post-menopausal women with many of the benefits as hormone replacement therapy (HRT): reduction of hot flashes, vaginal dryness and protection against heart disease and bone loss (osteoporosis). One study with mice showed that genistein (an isoflavone found in soy) had adverse effects on the development of cancer. This is an animal study and it’s unclear if the same effects will be seen in humans.
Whether soy can help protect against breast cancer in post-menopausal women is unclear at this time. Some researchers believe that soy consumption may actually increase the risk for breast cancer in post-menopausal women because the chemical structure of isoflavones is very similar to estrogen. Although experts say the effects are still unknown , no studies have clearly shown that that consumption of soy by humans increase breast cancer risk. Asian women, who consume more soy than Western woman, have a breast cancer rate one-fifth that of Western women. Also unknown are the effects of phytoestrogens on women who already have breast cancer or those at risk because of genetic factors.

A recent study “Breast and Uterine Effects of Soy Isoflavones and Conjugated Equine Estrogens in Postmenopausal Female Monkeys”, published in the The Journal of Clinical Endocrinology and Metabolism, suggested that high dietary levels of soy isoflavones do not stimulate breast or uterine proliferation in postmenopausal monkeys and may contribute to an estrogen profile associated with reduced breast cancer risk.

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