When I saw my Math teacher walking into the library, I quickly lowered my head as I sat at a carrel hoping that he wouldn’t see me. Surprisingly, he looked at me, smiled, and quickly looked away. He had just found one of his students skipping his class and said nothing. I was greatly relieved. I had spent most of the semester meeting with him after class as he helped me work through the various Math units that were being covered on the Grade 12 Departmental Exam. In those days, that exam was worth 100% of your mark and that mark would determine whether we were accepted into university. I was a shy, academic student who struggled with Math, but worked hard to at least memorize the formulas to plunk in the right numbers even if I didn’t always understand the concepts. However, when we came to the last unit – probability, my eyes glazed over, my brain cells stopped multiplying and my anxiety just kept increasing each time I stepped into that class. I decided that it was more important to review the other units than to sit in a class listening to a bunch of mumble jumble about having a jar that contains 2 red, 3 blue, and 4 green marbles. I had no idea whether Joe was going to draw a green marble and what the probability was that Tom was going to draw a blue marble. And I just didn’t care. My teacher must have sensed my limits since he did nothing about my daily absence during that unit!

And now forty years later, I am suddenly very interested in probability. Yesterday I was at the Cross Cancer Clinic where the oncologist recommended I begin taking radiation to lower the probability that I may still have some cancer. Because the cancer had extended 2/3 of the way into the uterus muscle, he believes I should have radiation on the vaginal sutures even though the uterus has been completely removed. He explained that there could be some remaining cancer cells that were left behind and now stuck in the sutures that occurred when the cervix was removed. Thinking in terms of probability, he said that the probability is that 10 out of 100 women could have that remaining cancer and he wants to lower that probability to 2%.

Considering all of the extremely difficult radiation and chemotherapy treatments that some men and women must endure, my treatment poses less side effects and less damage to other organs. However, there is still radiation that is being placed inside my body and I have spent a lot of time and money in the attempt to detoxify and get ride of my toxic overload!

Yesterday at the Clinic I agreed to this 5 days radiation treatment but last night I began second- guessing this decision. What is the probability that I could be one of those ten women who still have remaining cancer? What is the probability that I will be bothered by the side effects of the radiation? What is the probability that since my body is already on toxic overload and is not particularly healthy will react to the radiation? What is the probability that it will affect the progress of my chronic illness?

What is really missing is a lab test to determine if there are still cancer cells in the sutures! I understand George Boole’s comment about probability: “Probability is expectation founded upon partial knowledge. A perfect acquaintance with all the circumstances affecting the occurrence of an event would change expectation into certainty, and leave neither room nor demand for a theory of probabilities.” The problem is that I am expected to make a decision based upon partial knowledge.

Most of us want to believe that much of medicine is based on accurate lab reports and scientifically proven treatments and even though progress in these aspects of medicine is phenomenal, William Osler’s quote is still largely true: “Medicine is a science of uncertainty and an art of probability”.

However, in an attempt to increase my “partial knowledge” and to experience more “certainty”, I have just finished calling my doctor who specializes in environmental medicine and his receptionist is squeezing me in to see him as his last patient this morning. Hopefully as we further discuss the probability of which “marble” I might draw – the healthy cells or the cancer cells if I don’t receive this radiation, I will experience some peace of mind which decision is best for me. In the meantime I just ignored the Cancer Clinic’s call to schedule my Monday morning appointment. I will call them back this afternoon.

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