Blood Tests and Cancer.

   Newly discovered blood tests, some scientists are excitedly telling us, could detect early stage cancer, before it is causing any symptoms or signs.  The testing, of course is in its infancy and its accuracy is not yet validated.  The blood detection tests were carried out on patients already known to have the disease and in the  first run appeared to have about a 70% accuracy rate in those known to have the disease.  There is a great deal to be learned regarding the reliability, the  specificity and sensitivity of these tests, but that is not what this blog is about.   I'll leave such questions to the statisticians and cancer specialists.  Let us assume that the tests will prove to be acceptably reliable,(what is that?) where should we go from there?   Should we be launching an extensive, expensive and possible harmful investigation on test positive patients who are otherwise well?  Or should we be directing those funds towards people who are already diagnosed and are awaiting confirmation of diagnosis and treatment?
   We may have to make some very difficult  decisions.  The question is can we afford to go on such fishing expeditions when people with very treatable conditions are not receiving adequate treatment within an acceptable time frame because of  cost to the system?  What do we do when we catch a small or medium sized fish, when we have people with clearly established disease, on lengthy waiting lists for the consultations and diagnostic tests and treatment that they urgently need.  Even after diagnosis many wait excessive time until treatment.  There are those who can't afford treatment when it is not covered by a private drug plan.   Under the claim that it is better medicine, physicians and patients are being urged to do fewer tests under a program called 'Choosing Wisely'.  Those responsible for the development of the program disclaim being motivated by financial considerations although there could be huge saving if the profession and public is convinced.  We are told that complete physical examinations, the inexpensive sine qua non of  the medical method since the dawn of modern medicine,  is no longer necessary.  It is too expensive. It's not clinically productive, they say.   Those who say that show a lack of understanding of the very nature of the patient physician relationship.  They prefer to do tests, even when  they are not quite sure what they mean and even when those tests may ultimately result in a further cascade of tests which may ultimately harm the patient.  Unfortunately, over diagnosis and over treatment are sometimes the results of screening tests and can result in significant  mental and physical harm occurring. 
  These are difficult questions to answer, but when already diagnosed patients with serious illnesses that have proven management regimens cannot be adequately treated due to lack of resources, is it appropriate, or even moral to go on an expensive fishing expedition, the results of which are presently unknown?
Let me know what you think.