Breast Checks
According to a report from the Nordic Cochrane Centre in Copenhagen one in three breast cancer patients identified in public screening programs may be treated unnecessarily. Researchers said their results showed cancer screening programmes could lead to "overdiagnosis".
Writing in the British Medical Journal (BMJ), they said: "Screening for cancer may lead to earlier detection of lethal cancers but also detects harmless ones that will not cause death or symptoms. The research at the Cochrane Centre in Copenhagen analysed breast cancer trends at least seven years before and after government-run screening programs for breast cancer started in parts of Australia, Britain, Canada, Norway and Sweden.
Once screening programs began, more cases of breast cancer were detected up, the study showed. If a screening program is working, there should also be a drop in the number of advanced cancer cases detected in older women, since their cancers should theoretically have been caught earlier when they were screened.
However, Jorgensen and Gotzsche found the national breast cancer screening systems, which usually test women aged between 50 and 69, simply reported thousands more cases than previously identified
Overall, Jorgensen and Gotzsche found that one third of the women identified as having breast cancer didn't actually need to be treated.
Some cancers never cause symptoms or death, and can grow too slowly to ever affect patients. As it is impossible to distinguish between those and deadly cancers, any identified cancer is treated. But the treatments can have harmful side effects and be psychologically scarring.
The information needs to get to women so they can make an informed choice, says Jorgensen as there is a significant harm in making women cancer patients without good reason.
Jorgensen said that for years, women were urged to undergo breast cancer screening without them being informed of the risks involved, such as having to endure unnecessary treatment if a cancer was identified, even if it might never threaten their health.
Doctors and patients have long debated the merits of prostate cancer screening out of similar concerns that it overdiagnoses patients. A study in the Netherlands found that as many as two out of every five men whose prostate cancer was caught through a screening test had tumors too slow-growing to ever be a threat.
The National Health system recently dropped its pamphlet inviting women to get screened for breast cancer, after critics complained it did not explain the overtreatment problem.
A spokesperson for the chaarity Breakthrough Breast Cancer, said they hoped the research on the incidence of harmless breast cancers would not discourage women from attending screening.
Adding that unfortunately, it is currently not possible to predict which cancers found through screening will develop aggressively and which will grow very slowly. Based on all the current evidence, they believed the benefits of detecting breast cancer early still outweigh the risks."
Cancer Research UK said Britain's breast cancer screening program was partly responsible for the country's reduced breast cancer cases.
Tagged in Breast Cancer