Statistics, Cancer and a Soothing Classic

Do cancer statistics make you crazy?

Statistics are important, of course, and many of us want to know the outlook of our cancer situations. I have never been a big believer in prognostic statistics because I have known so many people who confounded them on both ends. There are, sadly, people who are diagnosed with what seems to be an early stage, quiet cancer, but who die from their disease. On the other side, there are many people who begin cancer treatment with a scary and dire situation and go on to live long and healthy lives. We never know. It is easy to say that, for any one of us, the survival is either 100% or 0%, but most of us need some other way to look at it.

In my mind, the best way is Stephen Jay Gould’s classic essay: The Median Isn’t the Message. This is especially on my mind today as I have just met two social work new clients who are terrified by the statistics related to their particular cancer diagnoses. It is always helpful to remember that each of us is “an 'n' of one”, but I think that reading Dr. Gould’s essay is even more empowering.

Dr. Gould was an evolutionary biologist who was diagnosed with peritoneal mesothelioma, a lethal form of cancer that carries a median mortality of eight months. Because he was a scientist, he immediately pondered those dire numbers and reminded himself that median means that half of the people will die before then and half will die later. In any curve, there are people at both ends, both the lucky end and the unfortunate one. He thought especially about the people who were at the lucky end and wondered how they got there and what their shared luck was about. It is impossible to really know, but he was determined to get into that group, and he did. Although I suspect that his oncologist never used the cure word, his cancer never progressed, and he died many years later of an entirely different kind of cancer.

It is all too easy to get hung up on numbers. Gould's essay is the perfect antidote both to people who believe that statistics don’t matter and to those who are convinced in their accuracy. It is especially distressing, as a patient, if your doctor falls into the latter group and may consign you, even just in her head, to the unfortunate end of the curve. We all do better with hope, and his essay can give you real understanding and a genuine reason to be hopeful—no matter what the statistics may say.

If you have never read his essay, this is the time to do so. If you have already read it, read it again. Here is the beginning, hopefully enough to grab your interest, and then a link to read more. Please do so.

From The Median Isn’t the Message by Stephen Jay Gould

My life has recently intersected, in a most personal way, two of Mark Twain's famous quips. One I shall defer to the end of this essay. The other (sometimes attributed to Disraeli), identifies three species of mendacity, each worse than the one before -- lies, lies, and statistics.

Consider the standard example of stretching the truth with numbers -- a case quite relevant to my story. Statistics recognizes different measures of an "average," or central tendency. The mean is our usual concept of an overall average -- add up the items and divide them by the number of sharers (100 candy bars collected for five kids next Halloween will yield 20 for each in a just world). The median, a different measure of central tendency, is the half-way point. If I line up five kids by height, the median child is shorter than two and taller than the other two (who might have trouble getting their mean share of the candy). A politician in power might say with pride, "The mean income of our citizens is $15,000 per year." The leader of the opposition might retort, "But half our citizens make less than $10,000 per year." Both are right, but neither cites a statistic with impassive objectivity. The first invokes a mean, the second a median.

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What do you think about statistics? Do they comfort or scare you? Please share your story in the BIDMC Cancer Community.