The Man with Two Watches

Readers may remember that on September 28th I wrote about a lab test, Mesomark, that measures a peptide (SMRT) produced by mesothelioma cells. The test is not sufficient to diagnose mesothelioma, but, given that I did not have enough tumor to be visible on CT or PET scans, I had hoped that it might be useful in monitoring changes in my tumor load. My Scott & White oncologist reviewed the packet of information about the test that I had given him and decided not to order the test.

He said that he would not use information from the blood test to make a treatment decision about chemotherapy; therefore, there was no reason to give the test. Also, he expected that it to be expensive (perhaps $1,000) and that my insurance would not cover it. I am disappointed, but upon reflection I agree completely with the logic of his decision.

The test is not well enough understood to be useful. As recommendations from the European Society for Medical Oncology state:

Recent data suggest the possible contribution of serum mesothelin-related proteins and osteopontin as useful markers to support the diagnosis of mesothelioma; however, the precise role of these markers is yet to be defined.

Also, medicine is a conservative practice, and doctors monitor their practice against established guidelines. Practice guidelines and consensus recommendations seem to guide practice and are of value to patients because they provide confidence that the treatment they are receiving is consistent with good practice. By sticking to established practices, doctors are probably protected from malpractice suits and are relieved of self-doubts about the correctness of their actions. As my doctor said, he would be anxious about what to do if the imaging and the blood test results seemed to be in conflict. He would have been like the man with two watches who is uncertain about what time it is.

Furthermore, the high and rising costs of medicine focuses everyone’s attention (especially insurance companies) on the medical rationale for tests and procedures. Even if a doctor wanted to depart from an established approach, the prospect of having to debate with an insurance company or one’s own employer might cause second thoughts.

Nevertheless, I was disappointed. I hate throwing away information, throwing away an opportunity to learn. I would not have expected my doctor to make a decision based on the test results, but I was curious about whether something might be learned that would improve treatment decisions in the future. The blood test might actually be a more sensitive measure of disease progression than CT and/or PET scan results, but there is no way to know without further research to clearly establish the link between tumor mass and SMRP levels. Giving the test to one patient would not make a meaningful contribution to that understanding and would only raise questions requiring further study, but it would have been interesting to know the results. The bottom line, however, is that it would not have been interesting enough for me to pay for the tests myself.

David

PS The second round of chemo went more smoothly than the first. I had less intestinal distress (ate multiple small meals and no chili dogs) and took less of my backup anti-vomiting medicine. I think those two factors made things easier.