发布于2018-12-28 11:34来源:原创 2 评论 3 点赞


Doc Talk: Fake News in Cancer



Fake news can lead to panic.



In September 2018, Singapore formed a parliamentary select committee to make recommendations on tackling the issue of fake news and the potential chaos in society that intentional falsehoods, particularly falsehoods concerning politically sensitive issues, may trigger. Society at large has also seen the need for the people to be imbued with a stronger ability to pick out false information.



Fake news exists aplenty, in the area of health and healthcare.



This too, can lead to panic.



And, such false information may not be always easy to pick out.



Many false claims concerning health on the Internet are so egregious that no sensible individual will likely take them for real. But surely, the results of a scientifically conducted blood test from a reliable laboratory will not give “false” information?



Think again.



Mr. C, a gentleman in his late forties, was seized by a sense of dread when he first consulted me. A blood test performed as part of his regular corporate-sponsored health screening check showed a cancer marker - CA 19-9 - was elevated.

C先生是一位年近五十的绅士,当他第一次来找我咨询时,可以感到他非常害怕。作为公司赞助的定期健康筛查的一部分,血液检查显示他的癌症标志物CA 19-9升高了。


Mr. C has done his homework through an Internet search before our meeting. Elevated CA 19-9 is associated with the diagnosis of cancer of the pancreas, so he read. To make matters worse, his mother just passed away from cancer of the pancreas six months ago.

在我们见面之前,C先生已经通过网络搜索得出了自己的结论。他了解到,CA 19-9的升高与胰腺癌的诊断有关。更糟糕的是,他的母亲六个月前刚刚死于胰腺癌。


Panic set in.



After sleepless nights and extensive evaluation with repeated blood tests, CT scans and evaluation of his stomach and colon with endoscopy, nothing remotely like a cancer was found.



Two years came and went. No cancer showed up. His cancer marker remained elevated.



Cancer markers may be elevated in the blood for causes other than the actual presence of a cancer. On occasions, the exact trigger cannot even be nailed down.




In all likelihood, this was a case of false alarm.



Ms. T, a lady in her fifties, turned up in my clinic with an obvious 2.5cm lump in her left breast. The lump turned out to be cancerous.



Breast cancer often takes a few years to grow to the size of 2.5cm. The first and only mammogram she did for breast cancer screening was more than 5 years ago. She had ignored subsequent reminders from her doctor to repeat the examination every 2 years.



Having experienced some discomfort associated with the compression of her breasts by the mammogram machine during her first check, she substituted the mammogram with an annual blood check measuring a cancer marker - CA 15-3 - that she learned, through her own search, could detect breast cancer. Her CA 15-3 was normal till the day I diagnosed her with breast cancer.

在第一次检查时,x光机压迫到她的乳房,这让她感到有些不适,于是她用每年一次的血液检查——癌症标志物CA 15-3检查——来代替x光检查。她自己通过搜索得知,这种标志物可以检测出乳腺癌。在我诊断出她患有乳腺癌之前,她的CA 15-3一直都很正常。


Cancers do not always secrete the common cancer markers that laboratories measure.



This was a clear case of false reassurance for the poor lady of being cancer-free.



Things get more confusing when what is scientifically sound gets mixed up with what is scientifically unsound.



Cancer markers in the blood have a role to play in medical practice. I use these markers often to track the progress of my cancer patients undergoing treatment, if by happenchance such markers are produced by the cancers, to see if their disease is responding. This would be sound scientifically.



But owing to the tendency for cancer markers in the blood to give false conclusions in people not previously diagnosed with cancer, the use of these blood tests for general cancer screening creates huge headaches. This would be unsound scientifically.



And this is the reason why the Ministry of Health through its public education efforts has been persuading Singaporeans in the right risk categories to consider screening mammogram for breast cancer and screening colonoscopy for colon cancer but has not, for once, advocated cancer marker blood tests for cancer screening.




The use of cancer marker blood tests to screen for cancer as part of a regular health check is popular among Singaporeans. Every week, scores of Singaporeans have these test performed. Indeed, there were cases of cancer fortuitously picked up by cancer marker blood tests.



But before you sign up for yours, do take into consideration the possibility of being hit by the “fake news” that you have cancer.



Think about the potential emotional chaos it may trigger.












  • 医生
  • 标志物
  • 科学
  • 癌症
  • 假消息