Cancer Screening

Cancer screening takes many forms. Mammograms look for breast cancer. Pap smears are done for cervical cancer. Colonoscopy is done for colorectal cancers.

I recently received an email from a reader in Georgetown. Her question was whether it made sense to do some kind of annual cancer screening using a blood test when other annual laboratory studies are done.

There are several aspects to this question. The first of them has to do with whether such a test is available. There is a test called Trucheck. It detects tumor cells in circulation in the blood stream. It is available in England. Their charges for the test are about £1200 (1200 pounds sterling). It is not very available in the United States.

Another test is called the Galleri test. It has been tested in the United States. It detects tumor cell DNA in the blood stream. A test costs $949. The lab that produces the test is certified by the Federal government. However, the test itself is not certified by the FDA yet.

The second aspect of this is how effective is the test. A study was done using the Galleri test. They looked at 5,921 patients over age 50. Of those 5,861 had no cancer detected. The remaining 59 patients tested positive for cancer. Of that group 34 proved to be false positive with no evidence of cancer. The other 25 patients tested positive and indeed had cancer.

That means that about 99 percent of the tests were negative. Of the remaining 1 percent, over half of them were false positives. That means that about 1 out of 200 people had a positive test diagnosing cancer. Given the $949 test cost, that means it cost $189,800 for each cancer detected. 

It could be viewed as that is not much to prevent a death. Alternatively, it could be viewed as that amount of money possibly saving more lives if spent in an alternate manner. There is not a clear answer.

There are also some bright spots to the testing. More than half of the cancers found are ones we do not normally screen for.  In addition almost half of the cancers found were still only at Stage I or Stage II.  This is very important. The test would not be of much value if it didn’t pick up cancers at an earlier stage so they can be treated.

Other studies are now going on. There are over 300,000 individuals involved in the various studies.

That leads to the third aspect of the test. Will medical insurance companies reimburse for the test being done. As long as it is not yet certified by the FDA, that is unlikely. They will also likely look at the cost to diagnose one case of cancer and be reluctant to fund something at that price.

There are some ways of obtaining payments for the test from outside sources. However, for individuals that would like to have the testing completed, they will likely have to pay for it themselves. 

An additional factor to take into account is whether an annual test like this will be more likely to get done than other screening procedures are now. Only 83 percent of women are up to date on Pap smears. Only 72 percent of women are up to date on mammograms. Only 67 percent of eligible individuals get colorectal screening done. If it was a simple as an annual blood test , perhaps we would have higher rates.

The bottom line here is that the test is still relatively new. We need to see the results in larger group numbers. It would help to have FDA approval. It would be worthwhile for that to lead to medical insurance coverage of the test. Even the website of the Trucheck test site indicates that they are the first step in “a future where early cancer detection becomes a reality.”

This clearly was a great question for the reader to bring up. It certainly addresses a cutting edge approach to cancer screening.