Musings of a Dinosaur

A Family Doctor in solo private practice; I may be going the way of the dinosaur, but I'm not dead yet.

Saturday, March 06, 2010

Polar Bears in the Amazon

I have a patient who has done quite well for the last several years with metastatic breast cancer. Every week or so she comes in for a blood test before her chemo. Every six months the oncologist sends her for a repeat staging workup of scans and blood work. And every six months, the patient tells me how anxious she gets awaiting the results of all these tests.

So every six months, in addition to the regular blood tests, I send off tumor markers at the request of the oncologist. Three different blood tests; they have always been normal.

This time around, I asked the patient if any of those tumor markers had ever been positive, even prior to her treatment. I checked the chart to confirm her impression: no, she had never had a positive tumor marker test.

This isn't particularly unusual. Not all cancers express proteins that can be measured in the serum. But the point of "tumor markers" is that when a tumor actually produces one, it should decrease (or disappear) after treatment, and its later reappearance ought to correlate with recurrence.

So what's the point of following tumor markers when a given tumor never produced them in the first place?

Sometimes oncologists sort of go on autopilot. Time to re-stage: order tumor markers.

Testing for things you can't possibly find. I suppose it's reassuring for the patient to hear that all the tests were negative, though it seems to be akin to setting up an early warning system for polar bears in the Amazon.

Excuse me while I make a phone call. I have to knock some sense into a certain oncologist.


At Sun Mar 07, 02:02:00 AM, Blogger Leigh Ann Otte said...

Oh my gosh. That's kind of scary actually. It's a good thing you caught it. Thank goodness she went to you!

At Sun Mar 07, 03:24:00 PM, Anonymous Anonymous said...

Good luck with that. Our oncologist here is pretty sense resistant.

At Sun Mar 07, 10:05:00 PM, Anonymous Anonymous said...

I hope that sense-knocking involves a smack upside the head.

At Sat Mar 13, 02:10:00 PM, Anonymous Anonymous said...

as an oncologist, i would go further and say that tumor markers were never indicated in the first place (except ER/PR/HER2neu on the original diagnosis), much less serially, with the _possible_ exception of alk phos which i would class as part of regular blood work. this a sin of commission, worse than that of omission (or at least autopilot), and a waste of money. and i say that as a full-on academic oncologist who loooves his tests... but only when they are actually somewhat justified by evidence.

and as a fellow internist (and yes, DB, some of us really do think of ourselves as internists first and foremost), i applaud you for calling the oncologist out even if i have to chide you ever so slightly for ordering them on his/her behalf for this whole time. :)


At Sat Mar 13, 02:27:00 PM, Anonymous Anonymous said...

oops, sorry, brainfart, didn't mean to brand you with the i-word (had DB on the brain, sorry). i know you're an FP with an even better breadth than us!


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