Living in dog years

Only once in the past three and a half years, since I found out I had metastatic colorectal cancer that had spread to my lungs, have any of my doctors said anything about how long I might live. At the beginning, my oncologist Dr. Kennecke noted that the median survival for patients with my condition is two years after diagnosis.

That was, I repeat, three and a half years ago. You might think that he predicted I had about two years to live, and was simply (and happily) wrong. But that's not even what he was saying. Because he used the word median, he meant that two years after diagnosis, half of patients with metastatic colon cancer are still alive. Therefore, in 2007, my chances of living more than two years were about 50% (assuming I was a typical patient—more on that below).

And he was right about that, since I'm still here. However, if I'd died within two years instead, he'd still have been right, since I would have been in the other 50%. You can see why doctors like using medians for survival prognoses!

Woe to the prognosticators

According to Slate, doctors are very, very reluctant to make any predictions about how long a specific patient will live, mostly because they're notoriously bad at it, unless the patient is pretty much at death's door—within days or hours of the end. In part that's also because they don't learn how:

[In] major medical textbooks that have been used by medical students (and practicing physicians) for decades [...] the relative percentage of space for each disease entity devoted to prognosis diminished with each subsequent edition, often to a paragraph or less. [Doctors] focus almost exclusively on the ever-expanding sciences of diagnosis and treatment, leaving prognosis almost entirely to the side.

But it's also difficult to predict correctly, especially for someone like me. A typical colon cancer patient is over 50 (maybe decades over), often with a family history of the disease, and perhaps other health problems that go with advancing age. I got the disease in my mid-30s, with no family history of it—and, later testing showed, no known genetic predisposition either—as well a relatively healthy body otherwise, despite having type 1 diabetes since 1991.

So my personal chance of survival two years past diagnosis was probably higher than the median, even if no one knew by how much. Plus my cancer team has felt it worthwhile to try all sorts of semi-experimental treatments, for which more typical patients might not have been eligible. And they've been willing to subject me to fairly high doses of chemotherapy—of which I'll get more on Monday—that I'm guessing might kill someone in more fragile health.

Time is not infinite

However, all that doesn't mean I'm likely to live an 80-year lifespan like your typical newborn Canadian in the 21st century. I've seen the CT scans, and I've watched my cancer progress slowly but relentlessly over the past few years. It's never been in remission, not once.

When my doctors talk to me about my treatments, they never use the word cure anymore. When they see a treatment as successful, that means it has slowed or stopped or maybe slightly reversed the growth of my tumours for a few months, or perhaps a year. Success means buying me time, extra months or perhaps years, but almost certainly not decades—unless, during those extra months, some remarkable new treatment becomes available, and it works for me.

I can hope for that, but I can't expect it. I'm 41 now. My own estimate, not made scientifically, but as an educated guess, is that I'll be pretty lucky if I reach 45. I'll be absolutely astonished if I celebrate my 50th birthday in 2019, and that's what I tell people now. (I was a little bit surprised to reach 40 last year.) The chances are pretty good that—in addition to my wife Air and my daughters and almost all of my friends—my parents, my aunts and uncles, and even our pup Lucy will outlive me. In other words, I'm living in dog years.

Like that initial median estimate, those are all probabilities, not certainties. There's no guarantee that my cancer will kill me within the decade, but being reasonable and realistic means I have to treat that as the most likely result, and live (and plan) accordingly. That's not easy to do, especially for a procrastinator like me, but there it is.

By the way, most of you will have to do the same eventually, but with any luck not until your 70s or 80s. My time is probably briefer than most, and I don't like that. I'm not okay with it. But I can live with it. Woof woof.