Two new reports on the use of Tamoxifen came out recently and while reporting on it, I also wanted to give our doctors the opportunity to respond. The findings of the research seem to indicate that Tamoxifen could be more widely prescribed, and that is something that natural bio-identical hormone prescribing doctors have opposed from Dr John Lee onwards. Read the report, and what Drs Shirley Bond and Tony Coope think, and make up your own mind.
This appeared in Science Daily and stated that Tamoxifen, prescribed for certain women as a preventive measure against breast cancer, saves lives and reduces medical costs. That is the conclusion of a new study published early online in Cancer, a peer-reviewed journal of the American Cancer Society. The study’s results suggest that the benefits of Tamoxifen in preventing cancer can sufficiently compensate for its side effects in post-menopausal women under age 55 who have an increased risk of developing breast cancer. I quote:
“Research has shown that Tamoxifen can protect against breast cancer for years after treatment ends, but identifying the group of women who can most benefit from the drug as a cancer preventive agent, without experiencing serious side effects, is a challenge. Side effects of the drug can include pulmonary embolism, endometrial cancer, deep vein thrombosis, and cataracts, as well as hot flashes and early menopause.
To discover those women who would benefit the most from taking tamoxifen as a cancer preventive drug a mathematical model to was used to simulate a post-menopausal population under age 55 years in a ‘virtual’ clinical trial comparing Tamoxifen treatment with no treatment. They assessed the effects that Tamoxifen would have on women’s breast cancer risk for 10 years following the end of treatment. Cancer incidences and survival information were taken from the Surveillance Epidemiology and End Results cancer registry, while factors such as non-cancer disease incidences, quality of life, and costs were taken from the medical literature.
The researchers found that in post-menopausal women aged 55 and younger with a 5-year risk of developing breast cancer of 1.66 percent or greater, the benefits of Tamoxifen are maximized while its side effects are minimized. “In this group of women, using tamoxifen to prevent breast cancer saves lives and has a low frequency of side effects,” said chief researcher Dr. Alperin. He added that it also saves medical costs. “Specifically, chemoprevention with tamoxifen prevents 29 breast cancer cases and 9 breast cancer deaths per 1,000 women treated, and it saves $47,580 per 1,000 women treated in the United States.”
Following on from the previous report, the UK’s first study to predict which women with a high risk of breast cancer will benefit from taking Tamoxifen as a preventative measure is currently taking place in Greater Manchester, with ongoing recruitment.
Researchers at the Nightingale Centre and Genesis Prevention Centre – based at University Hospital of South Manchester’s (UHSM) Wythenshawe Hospital – will invite 200 pre-menopausal women between the ages of 33 and 46 who attend the centre’s Family History Clinic to join the study over the next 12 months.
The study will assess the benefit of taking Tamoxifen to prevent breast cancer – for which it is widely prescribed in the USA – in the chosen demographic. It will look at changes in biomarkers and breast density in the women and also measure the cost-effectiveness of prescribing preventative Tamoxifen.
Tamoxifen is currently prescribed in the UK to some breast cancer patients as a form of treatment. However, it is not yet licensed as a preventative drug. The research team, led by Professor Tony Howell of the Nightingale Centre and Genesis Prevention Centre, hopes to show evidence that may lead to the introduction of Tamoxifen as a preventative drug in Family History Clinics throughout the UK.
He explained: “Previous studies have revealed that Tamoxifen can prevent up to 40 per cent of breast cancers in high risk women*. We’ve also shown that Tamoxifen can reduce the density of breast tissue, which is also a indicator in preventing breast cancer. What we now need to do is identify which specific group of women will benefit from taking Tamoxifen as a preventative drug, in the hope that we can use it in the UK for that purpose.
The women recruited who agree to take Tamoxifen will be prescribed the drug for 12 months before being re-assessed. They will then be given the option to continue taking Tamoxifen for a further four years. The study will also measure women’s perceptions about continuing the treatment and its potential benefits, based on the individual’s first year of results.
Patients will be provided with a specially developed decision aid booklet to help weigh up the risks/benefits of taking tamoxifen and continual efforts will be made to improve the booklet during the one-year recruitment period to the study.
Professor Howell explained: “One of the obstacles we’re facing is the current perception of Tamoxifen and the potential side effects that can occur from taking the drug. We hope to improve the situation by educating patients and assessing the benefits of them taking Tamoxifen. This way, they can assess the pros and cons for themselves when deciding whether to continue taking the treatment.”
Response by Dr Shirley Bond
Tamoxifen is known to have all these side effects and I find it very difficult to recommend its use especially as its success rate in preventing the recurrence of breast cancer is not that clear. Recurrences seem to occur in quite a number of women after they stop the Tamoxifen, which they are required to do after a set number of years.
I have always believed that you should “Add life to your years rather than years to your life.”
Response by Dr Tony Coope
This is quite a complicated subject. Although it is claimed that the benefits of tamoxifen ‘far outweigh the potential risks’, those risks are serious ones: deep vein thrombosis, pulmonary embolism and uterine cancer are all potentially directly fatal, and cataracts indirectly so if you can’t see where you are going!
One problem with tamoxifen, which blocks the action of estrogen (the hormone that ‘instructs’ breast cells to multiply) is that it only works in women with estrogen receptor-positive breast cancer. In addition, although tamoxifen acts as an ‘anti-estrogen’ in breast tissue, it acts like an estrogen in other tissues such as the womb, hence the increased risk of malignancy there. Women may also have an increased tendency to menopausal symptoms such as hot flushes and vaginal atrophy (anti-estrogen effect), or they may have benefits such as a reduced risk of osteoporosis ( positive estrogen effect).
The use of a complex mathematical model to try to elucidate which groups of women tamoxifen may benefit is understandable, but the accuracy of its findings depend entirely on the quality of the data fed in – according to the GIGO principle (Garbage In, Garbage Out). In this trial, one has to ask: “Why were only post-menopausal women under age 55 included? Do women over that age show significantly more negative results? And if so, how can this be explained, – is it to do with the gradual loss of vitality and life-energy with age that leads to an inability to compensate for the negative properties of the drug?
The sad and frustrating thing is that there are much safer ways of reducing breast cancer risk. Bio-identical progesterone confers the benefits of tamoxifen without either its serious or its milder side effects. And risk can theoretically be further reduced by supporting the metabolic detoxification of estrogen in the liver by supplements such as DIM and indole-3-carbinol, and a diet rich in cruciferous vegetables, antioxidants, and traditional Indian spices.
Then on a subtler level there are ways of resolving issues around self-worth that may have led women with cancer of the breast to consistently nurture others at the expense of self, while being unable to ask for the same in return; a pattern that I am certain prepares the ground for the development of such an illness.