Almost one in 4 cancers diagnosed in men in 2012 were overdiagnosed, based on our recent research published today. Medical Journal of Australia.
That same 12 months, we found that girls were overdiagnosed with about one in five cancers.
Overdiagnosis occurs when an individual is diagnosed with “harmless” cancer that either never grows or grows very slowly. These cancers are sometimes called low- or very low-risk cancers and don't spread or cause any problems if left untreated.
This level of over-diagnosis means Australian men are 17 per cent more prone to be diagnosed with cancer of their lifetime than they were 30 years ago, while women are 10 per cent more likely.
Overdiagnosis of cancer may end up in people receiving unnecessary treatments, resembling surgery, radiotherapy and hormone therapy. A cancer diagnosis and cancer treatment can take a physical, psychological and financial toll.
How many cancers are overdiagnosed?
In 2012, 77,000 Australian men were diagnosed with cancer. We estimated that 24% of them (or 18,000 in total) were overdiagnosed, including:
- 8,600 prostate cancer
- 8,300 melanomas
- 860 kidney cancer
- 500 thyroid cancer.
About 55,000 cancers were diagnosed in women. Of these, 18% (11,000) were overdiagnosed. This includes:
- 4,000 breast cancers
- 5,600 melanomas
- 850 Thyroid cancer
- 660 kidney cancer.
These calculations are based on changes within the lifetime risk of cancer since 1982, after adjusting for other causes of death and risk aspects.
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Because they're more common, prostate and breast cancer and melanoma account for the biggest variety of overdiagnosed cancers, although a big percentage of thyroid cancers were overdiagnosed.
Among women, for instance, 73% of thyroid cancers were overdiagnosed, while 22% of breast cancers were overdiagnosed.
Damages to patients come from unnecessary surgery and other treatments, in addition to inconvenience and expense.
Three out of four patients with thyroid “cancer” are overdiagnosed.For example, almost everyone could have their thyroid completely removed, prone to complications, and might want to take alternative thyroid medication for the remaining of their lives.
In addition, there are substantial costs to the health system, and obligatory surgeries are delayed.
Some of the “good news” is that overdiagnosis appears to be mostly limited to the five essential cancers listed above.
What causes cancer to be overdiagnosed?
The explanation for overdiagnosis is different for every cancer.
For prostate cancer, the explanation is the hunt for early detection of prostate cancer using a prostate-specific antigen (PSA) blood test. A downside of PSA testing is the danger of detecting large numbers of low-risk prostate cancers which might be more treatable.
Early detection of breast cancer can be possible, through mammography screening that may detect low-risk cancers.
Similarly, the detection of low-risk melanoma accounted for the overdiagnosis of most melanomas we observed. Early detection activities are again a possible cause, with again and again more skin biopsies being performed today than 30 years ago.
Overdiagnosis of kidney and thyroid cancers is basically resulting from “incidental” findings — abnormalities found incidentally on imaging done for other reasons — or through overdiagnosis of mild thyroid problems. .
What can we do about it?
Some degree of overdiagnosis is inevitable in a contemporary health care system committed to screening to scale back the burden of disease and death from cancer.
We need to detect high-risk cancers early enough to offer one of the best probability of cure through early surgery and other treatments.
But it's still possible if steps are taken to forestall overdiagnosis and overtreatment of low-risk cancers that go undetected.
Take South Korea for instance. After introducing a screening program for thyroid cancer, Malik noticed A 15-fold increase In small, low-risk thyroid cancers. Then it reduced the initial detection. This led to a big reduction in thyroid cancer rates with none change in death rates.
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PSA testing rates in Australia are Among the highest in the world. Countries where PSA testing is low, eg United KingdomDetect low-risk prostate cancer, and subsequently receive less treatment.
Rather than simply accepting PSA testing, there may be a wiser strategy. Make an informed decision whether to go ahead with it or not.. Tools can be found to enable you to select. Here And Here.
Oh Decision support It can be available for Australian women to come to a decision whether or to not proceed with mammogram screening.
Trials of windback treatment of low-risk prostate cancer have yielded results. Clinical practice guidelines that supply energetic surveillance as an alternative choice to immediate surgery or radiation therapy for men with low-risk prostate cancer.
Trials are actually underway to guage less treatment for low-risk breast cancer and may in the future help eliminate more treatment for breast cancer.
New screening tests that discover clinically significant cancers, while not detecting indolent and never-growing cancers, are the Holy Grail. But it might take a while for them to reach.
In the meantime, health services have to remain vigilant. Monitoring of new areas of higher assessmentEspecially when investing in recent technologies which have the potential to further increase valuations.