When I was first diagnosed with pancreatic cancer, I was given a terrifying number: 10. On average, someone diagnosed with Stage 4 pancreatic cancer has ten months to live.
And what sounds scary is the fact that I was given this statistic a little over seven months ago, which makes it sound like I have only about three months left to live.
But this logic isn’t right. I have survived the last seven months (actually, I’ve lived the last seven months intensely), and so the number I should be concerned with is not
- “How many months, on average, does the diagnosed Stage 4 pancreatic cancer patient, who has just been diagnosed, have?”
- “How many months, on average, does the Stage 4 pancreatic cancer patient, who is still alive after seven months, have?”
The answers to these two questions are different, because they take their averages from two different sets of people. To answer the first question, your set would include everyone who’s been diagnosed with Stage 4 pancreatic cancer. And that means including all the people who did not make it to seven months: those who died within one month after their diagnosis, two months after their diagnosis, and so on.
But to answer the second question, you would not include everyone. You would exclude all those people who died within seven months of their diagnosis. And so the average number of months this group of stage 4 pancreatic cancer should be higher. In other words, the answer to the question “how many months do I have left?” should be more than three months.
The difficult thing is that I have no idea what the answer to the second question is or how many more months I actually do have.
But I’ve recently got on good terms with uncertainty, which is a good thing, since uncertainty — about life and death no less — has forced its way to become my constant companion.