February 2009

Breast cancer screening peril

In a letter to The Times 23 signatories accuse the NHS Screening Programme of failing to provide women with all the facts when inviting them to routine breast cancer checks . They say that ‘none of their invitations for screening comes close to telling the truth. As a result, women are being manipulated…into attending’. The letter says that ‘there are harms associated with early detection of breast cancer by screening that are not widely acknowledged’. It notes that many breast cancers will not do any harm if left alone; but once detected, a woman may go on to a conveyor belt of unnecessary and often aggressive treatment, including surgery, radiotherapy and possibly chemotherapy.
This letter was published the day before an analysis by the Nordic Cochrane Centre of breast cancer and screening was published in the British Medical Journal. The analysis concluded that the information distributed by the NHS was one sided and misleading for those invited to take part. While it talks of the benefits of attending the programme, it does not tell them of the disadvantages i.e. the possibility of over-diagnosis, misdiagnosis, the potential harm of the treatments for cancer and the psychological trauma of being given a cancer diagnosis. They say ‘The leaflet has the authoritative title Breast Screening: The Facts suggesting that the information can be trusted…[but] it is inadequate as a basis for informed consent’. Their research showed that if 2000 women were screened regularly for 10 years, one would avoid dying from breast cancer, but 10 healthy women would be treated unnecessarily and a further 200 healthy women will have a false alarm.
The Nordic Centre study, led by Peter Gotzsche, notes that despite the fact that20% of cancers detected by screening were DCIS cases, the NHS leaflet makes no mention of this. Fewer than half of DCIS cases become invasive cases and it is often referred to as a pre cancerous condition. DCIS has been found to exist harmlessly in the breasts of about 9% of women at post mortem, but the increased use of mammography has led to vastly increased rates of DCIS being reported. One of the signatories to The Times letter, Professor Michael Baum, said that more cases should be treated like many prostate cancer cases, with a number of men allowed to live with the cancer and often dying of unrelated causes. He said ‘the number of invasive breast cancers being detected is not falling, despite the number of cases picked up by screening rising dramatically… You would expect serious cancers to drop because the early detection means the DCIS cases are not progressing. It just doesn’t add up.’ He has said that instead of screening the whole female population over the age of 50, every 3 years, women should be tested according to their level of risk.
However, the study is disputed by the NHS who report that the national screening programme detects more than 14,000 cancers annually and saves 1,400 lives. They add that 79% of cancers detected through screening are invasive. Professor Peter Johnson, Cancer Research UK's chief clinician, said that any debate about the details "should not be allowed to distract anyone from the benefits of breast screening".
"Screening offers the best possible opportunity for early diagnosis of breast cancer and experts agree that this means a better chance of successful treatment," he explained.
"The information women receive at time of screening is based on careful research into the views of the women being screened. Improvements can always be made and we are contributing to a review by the Department of Health.”

19th February 2009
including surgeons, GP’s, oncologists, public health specialists and patient representatives
Done by mammography
Currently available to all women aged 50-70 every three years. It is to be extended to include women from 47-73 by 2012.
Ductal carcinoma in situ

Sources and Information:
The Times
The Sunday Times
Cancer Research UK
NHS
‘Breast Screening: the facts - or maybe not’ by Peter Gotzsche et al in the BMJ 2009;338:b86


Decline in breast cancer risk when HRT use stopped

The results of a US study, published in the New England Medical Journal, has provided further evidence that post menopausal women who take HRT (combined oestrogen plus progestin hormone therapy being the most commonly prescribed HRT in the UK) face a greater risk of breast cancer, but that when they stop taking HRT, the risk falls sharply again.
The study was part of a larger trial, started in the early 90’s, investigating post menopausal women. The HRT part of the study was stopped in 2002, when researchers found that women taking HRT had higher rates of breast cancer than those taking a placebo. This was followed by a significant drop in the number of women taking HRT, which was in turn followed by a corresponding fall in breast cancer rates. There has been much debate on whether these two facts are linked, but in this latest study, the researchers were satisfied that there was a clear link.
The study continued monitoring 15,000 women from the original study, who had all been urged to stop taking HRT in 2002 and compared this with data from women not originally involved, who had been given no specific advice on giving up. In the first group, the incidence of breast cancer was much higher in the 5 years up to 2002, but then fell rapidly, with diagnosed cases falling by 28% in a year. These women had approximately the same number of mammograms before and after 2002. This is relevant as some had argued previously that a reduction in the frequency of mammograms among women who stopped taking HRT might have contributed to the apparent fall.
Many women in the other group of women chose to stop taking the therapy and this coincided with a 43% fall in breast cancer rates between 2002 and 2003. Women in this group who continued taking HRT were at a higher risk of cancer, with the risk doubling for every 5 years of taking the HRT.
Dr Marcia Stafanik (co author and professor of medicine at Stanford University) said:
‘You start women on hormones and within five years, their risk of breast cancer is clearly elevated. You stop the hormones and within one year, their risk is essentially back to normal. It’s reasonably convincing cause-and-effect data’.
Dr Rowan Chlebowski, (chief investigator at the Los Angeles Biomedical Research Institute and lead author of the study) advised:
‘Postmenopausal women and their physicians should consider these findings in weighing the risks and benefits of combined oestrogen plus progestin use, especially if the women plan to take the medication for more than five years’.
Professor Valerie Beral (director of Cancer Research UK Epidemiology Unit at Oxford University) said:
‘There has been a big drop in HRT use since 2002. Because of this about 1000 fewer UK women are developing breast cancer every year’.
However, Dr David Sturdee (president of the International Menopause Society, which represents HRT specialists) is not convinced. He said:-
‘There’s no doubt there has been a drop in breast cancer rates, which is good news, but this started before the reduction in HRT use. Breast cancer takes years to develop, so if this drop was due to stopping HRT, we wouldn’t be seeing it just yet. There’s something happening, which is worth investigating, but it’s unlikely to be HRT.

Sources and References:-
BBC News
Cancer Research News
Chlebowski RT et al. Breast Cancerafter use of estrogen plus progestrin in postmenopausal women.
N Engl J Med Feb 5; 360:573

Hormone injections improve survival in premenopausal breast cancer patients

A study in the Journal of the National Cancer Institute is thought to be the first to look at the long term impact of goserelin (more commonly known as Zoladex and given by injection) and its effectiveness compared to tamoxifen, an oestrogen blocking drug. Cancer Research UK scientists and their colleagues have shown that treatment with goserelin improves long term survival in premenopausal breast cancer patients.
Hormonal therapies interfere with the production or action of particular hormones in the body. Most breast cancers need supplies of the hormone oestrogen to grow. Production of oestrogen by the ovaries is stimulated by a hormone called leuteinising hormone, which is produced by the pituitary gland in the brain. Zoladex stops the production of leuteinising hormone from the pituitary gland, which leads to a reduction in oestrogen levels. The cancer cells then grow more slowly or stop growing altogether. The cancer may shrink in size.
Researchers recruited over 2700premenopausal women with breast cancer and placed them randomly in one of four treatment groups, receiving either Zoladex, tamoxifen, both drugs or neither one, for 2 years.
It was found that women who were given Zoladex experienced similar outcomes to those taking tamoxifen. 15 years after the start of treatment there were 8.5 fewer deaths per 100 and 13.9 fewer recurrences per 100 among those who were given Zoladex alone than among those taking neither drug. There was no significant benefit from taking both drugs.
It seems that based on long term follow up of this trial, Zoladex is as effective as tamoxifen when each are given for 2 years. Researchers said:
‘IT may be that women who are unlikely to complete 5 years of tamoxifen tablets may prefer two years of goserelin injections.’

Sources:
Cancer Research UK
Cancerbackup