No Comfort in Statistics

The New York Times ran a really nice piece Monday called "Finding Little Comfort in the Statistics of Survival." It's written by a doctor who was diagnosed with breast cancer; she struggles with the various ways that the size of her tumor is measured, and with the implications of the size -- a certain measurement will mean she is at a different stage, and thus has a different statistical chance of survival. The piece is really about the effect that such numbers can have on a cancer patient. She gets (relatively) good news in the end, but it's no comfort to her.

Some lessons to be learned here.

The first is about the arbitrariness of some of the numbers that cancer patients might receive. As this article points out, four different tools for measuring a tumor (CT scan, ultrasound, etc.) can offer four different figures. It's too inexact. A different radiologist, a different technician, a different angle while lying on the table, and there's a different result. It's all the same tumor, but it means a different treatment, or a different night's sleep. It's hard, maybe impossible, to step back and be objective about it while the doctor is giving you results, but I think that's important to remember.

The second lesson is the difficulty of evaluating survival rates. Like the surgeon in the story says, when the author mention survival rate tables, "But that's not you." We aren't statistics. There are way too many factors involved with each of our cancers to start worrying about where we fit into the table -- the average of hundreds or thousands of people with cancers that might be like ours, but might be really different. (Plus, most of those tables are for Overall Survival -- they measure how long before people dies of anything -- cancer, but also heart attacks, plane crashes, choking on ham sandwiches, whatever.)

As I've written before, I've pretty much sworn off of numbers. They bring me no comfort when they're good, and the times I've been deeply depressed about my cancer, it's been because of numbers, obsessing over the what-ifs that the author of the Times piece obsesses over.

I have lymphoma pals who feel just the opposite. They can tell you just how big their nodes were, what their Uptake Values were for their last PET scans, what their LDH levels were for their last blood tests. They need something concrete to hang on to. God bless them. But I just can't do it. When I had my last scan a couple of months ago, Dr. R left a message with the results. "Things actually look a little better than the last scan," he said. "Call me if you want the details."

I never called. My wife and my mom wanted me to, I know, dropping subtle hints that I should call.

But why? So I can know that my nodes were 1.8 centimeters a month after I stopped Rituxan, and now they're 1.6? To me, that's not much comfort. I know my nodes aren't going anywhere. In 6 months, they could be back up to 2.8, or 3.6.

That's not pessimism. Just the opposite. I expect that we'll be around for a long time, my nodes and me.

No sense in paying them more attention than they deserve.