A study conducted at Harvard University suggests that breast cancer screening is not actually as beneficial as previously thought. Routine screening leads to an increased number of false positives, meaning that women are diagnosed with cancer when they do not actually suffer from it. And in spite of this the death rates from breast cancer are not lower.
The research involved 16 million women who were at least 40 years old. The study indicates that because of the fact that women are wrongly diagnosed with cancer they undergo chemotherapy for tumors which would not have actually caused problems.
Breast cancer screening is supposed to reduce the mortality caused by this disease since it allows doctors to detect cancer at an early stage. Previous research has proved that mammography programs can reduce death rates by up to 25 percent, whereas other data suggests that it is actually less than 10 percent. But researchers from the University of Strathclyde and kings College London say that past studies did not take into account the progresses made in cancer treatments which are highly responsible for increasing the survival rates.
Researchers from Harvard University believe that increasing the number of breast cancer screening only leads to an increased rate of overdiagnosis. The study published in the journal JAMA Internal Medicine compared the health records of the 16 million women and also looked at the extent to which mammograms were used in 547 states from the US. The findings suggest that in regions were mammograms were used more often the number of women who were diagnosed with breast cancer also increased.
However if the screening were effected the researchers should have also discovered a corresponding decrease in the death rates, but they did not identify such a thing. Instead the researchers observed a 25 percent increase in the identification of small breast cancers, but not a reduction in the case of large tumors.
In the records 53.207 women were diagnosed with breast cancer and were observed for ten years. It seems that in the areas where breast cancer screening was used 10 percent more often than the average the number of cancer diagnoses was 16 percent higher even though the number of deaths remained the same.
The lead author of the study Professor Richard Wilson, remarked:
“What explains the data? The simplest explanation is widespread overdiagnosis, which increases the incidence of small cancers without changing mortality, and therefore matches every feature of the observed data.”
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