Ask the Doctor
May 20, 2014
Can a blood test be used to diagnose cancer?

Dear Doc,

I was browsing through the Internet and read about blood tests that can be done to diagnose cancers. It seems very simple and straight- forward to me, so why do we see so little of this done here?{{more}}

Kenny

Dear Kenny,

Indeed, there are blood tests that can be done to give indications of the possibilities of having or developing a cancer. These are called tumour markers; for example, CA125 is a noted marker for ovarian tumours. These tests are available locally and are used by doctors in their assessment of patients.

There has always been and still continues to be the hunt for “tumour markers” that are specific to a cancer. That has eluded science so far although there are tumour markers for certain cancers, they are not specific to any one cancer and indeed not specific to cancers alone. CA125, which is an established marker for ovarian tumours, can be present during other non-cancerous gynaecological conditions. Some markers may not even increase during cancers or may only do so when the disease is far advanced.

The reality is that we have to combine all other methods in assisting in diagnosing cancers. We are not near to the Star Trek era of a quick scan and you are done.

Doc

SVG Cancer Society,

P.O. Box 709, Kingstown.

Email: svgsocietycancer@gmail.com

Phone: 526-7036