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Mammograms
mammogramThe data therefore show that for every 1000 women screened through 12 years, one breast-cancer death is avoided but the total number of deaths is increased by six. On the other hand, those who believe the Swedish trials (apart from the Malmö trial) are biased have to accept that there is no reliable evidence that screening decreases breast-cancer mortality.

Comment:

This report in one of the world's leading medical journals is quite different that what is by and large believed and accepted by most of the medical community. The majority view is that mammograms are beneficial and life saving. However, there will always be a bias to that which is already accepted as a "fact" and has been promoted by the medical and governmental systems. People in general do not like to admit they could possibly have made a mistake and the reluctance to admit an error is amplified when it is a belief that is accepted by the majority of society and still even further amplified when an entire profit generating system has been constructed around that belief.

One very disturbing piece of information is obtained by simply looking at the graphs (which obviously cannot be done here) in the second study (Miller, et. Al). Here it becomes obvious that the mortality for the group receiving mammography was GREATER for the first 11 years than the group that did not. This means that you increase your risk of dieing if you are age 40 to 49 and you get a mammogram.

Aside from the issue of whether mammograms are effective or not, it is still a form of early detection and not true prevention. A much smaller effort has been placed on true prevention than the higher technology based interventions. For example:

"In terms of attributable risk, the authors conclude that "if all postmenopausal women in the population modify their saturated fat intake to (that of the lower one-fifth of the population), the current rate of breast cancer would be reduced by 10% in postmenopausal women ... were to increase fruit and vegetable intake to reach an average daily consumption of vitamin C (equivalent to that of the highest one-fifth of the population), risk of breast cancer ... would be reduced by 16%." The effects were approximately additive, and simultaneously make both changes would reduce the risk by 24%" ("Vitamin C and Cancer Prevention: The Epidemiologic Evidence", American Journal of Clinical Nutrition)

And there are other factors to decrease a person's risk of not only cancer but of other diseases as well. Eliminating smoking, alcohol and drugs, pesticides and other chemicals, and plastics all has a positive impact on cancer risk. Increasing fruits and vegetables, essential fatty acids, antioxidants and minerals, fresh air, stress management, and exercise all lead to a healthier body and lowered chance of developing disease. If we focus on a daily basis on the positives in regards to our health then we will be making a significant progress in disease prevention and improving the quality of all our lives.


The Canadian National Breast Screening Study-1: breast cancer mortality after 11 to 16 years of follow-up. PDF Print E-mail
Tuesday, 03 September 2002 00:00
"BACKGROUND: The efficacy of breast cancer screening in women age 40 to 49 years remains controversial. OBJECTIVE: To compare breast cancer mortality in 40- to 49-year-old women who received either 1) screening with annual mammography, breast physical examination, and instruction on breast self-examination on 4 or 5 occasions or 2) community care after a single breast physical examination and instruction on breast self-examination. DESIGN: Individually randomized, controlled trial. SETTING: 15 Canadian centers. PARTICIPANTS: 50 430 volunteers age 40 to 49 years, recruited from January 1980 to March 1985, who were not pregnant, had no previous breast cancer diagnosis, and had not had mammography in the preceding 12 months. INTERVENTIONS: Breast physical examination and instruction on breast self-examination preceded random assignment of 25 214 women to receive mammography and annual mammography, breast physical examination, and breast self-examination and 25 216 women to receive usual community care with annual follow-up. MEASUREMENTS: Verified breast cancer incidence and cohort mortality through 31 December 1993 and deaths from breast cancer through 30 June 1996. RESULTS: The 105 breast cancer deaths in the mammography group and 108 breast cancer deaths in the usual care group yielded a cumulative rate ratio, adjusted for mammography done outside the study, of 1.06 (95% CI, 0.80 to 1.40). A total of 592 cases of invasive breast cancer and 71 cases of in situ breast cancer were diagnosed by 31 December 1993 in the mammography group compared with 552 and 29 cases, respectively, in the usual care group. The expected proportions of nonpalpable and small invasive tumors were detected on mammography. CONCLUSION: After 11 to 16 years of follow-up, four or five annual screenings with mammography, breast physical examination, and breast self-examination had not reduced breast cancer mortality compared with usual community care after a single breast physical examination and instruction on breast self-examination. The study data show that true effects of 20% or greater are unlikely."

"The Canadian National Breast Screening Study-1 (CNBSS-1), an individually randomized trial in women 40 to 49 years of age at study entry, evaluated the efficacy of annual mammography, breast physical examination, and instruction on breast self-examination in reducing breast cancer mortality. The 7-year and preliminary 10-year mortality results were previously reported. At 7 years, 38 women in the mammography group and 28 women in the usual care group had died of breast cancer, for a rate ratio of 1.36 (95% CT, 0.84 to 2.21). At 10 years, there were 82 breast cancer deaths in the mammography group and 72 in the usual care group (rate ratio, 1.14 [CI, 0.83 to 1.56]). This article reports CNBSS-1 results after an average 13-year follow-up from study entry."

"In CNBSS-1, combined screening of women age 40 to 49 years with annual mammography and breast physical examination for up to 5 years did not reduce breast cancer mortality compared with women who had a single breast physical examination and subsequent care from Canada's universal health care system. We would not expect this null result to be explained by the instruction of both groups in breast self-examination, although such instruction may benefit younger women."
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Is screening for breast cancer mammography justifiable PDF Print E-mail
Saturday, 08 January 2000 00:00
"After heated controversy, there now seems to be general acceptance that the benefit of screening for breast cancer with mammography has been well documented. Large randomized trials, including a total of half a million women, have been carried out in New York, USA; Edinburgh, Scotland; Canada; and Malmö, Koppargberg, Östergöland, Stockholm, and Göteborg in Sweden. A meta-analysis of an update of the five Swedish trials, which used data from individual patients, was particularly influential. It showed that screening lowered mortality from breast cancer by 29% in women aged 50-69 years. The findings of a 1999 epidemiological study were therefore surprising. It found no decrease in breast-cancer mortality in Sweden where screening has been recommended since 1985. The observed decrease in number of deaths from breast cancer was 0.8% (not significant), whereas the expected decrease was 11%. Although this study can be criticized, it raises once again the issue of the reliability of the evidence that screening is effective."

"The imbalance in age at baseline in the Swedish trial is important. Nyström and colleagues reported in a specialist journal that the screened women had an increased risk of death (relative risk 1.05; 15,695 women died of 156,911 in the screening group vs 11,887 of 125,866 in the control group). Nyström and colleagues did not test whether this increased mortality was significant, nor did they give a CI [Confidence Interval]. They argued that because breast-cancer mortality constitutes less than 5% of the total mortality, such an analysis "would require very large cohorts and is therefore impossible in practice." … The effect of screening programmes, if any, is small and the balance between beneficial and harmful effects is very delicate. Unfortunately, the randomization process failed to create similar groups in six of the eight trials of mammographic screening."

"We could not assess psychological morbidity related to false-positive findings because this feature was not reported in the trials. In the USA, Elmore and colleagues estimated the 49% of screened women will experience at least one false-positive mammogram during ten screening rounds and that 19% will be subjected to biopsy. In the Swedish trials, false-positive rates of 4-6% have been reported, corresponding to an average risk of 40% of a false-positive mammogram during ten rounds."

"We conclude that screening for breast cancer with mammography is unjustified."
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