Finding Little Comfort in the Statistics of Survival
By ELLEN D. FELD, M.D.
Published: October 17, 2011
The new edition arrives, and I’m off. Straight to the index. To the B’s. To breast cancer.
Ellen Weinstein
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This medical textbook is revised every year. And every year when my new copy comes, just ahead of my new students, I can’t stop myself. Like a tongue to a sore tooth, I go right for the table of statistics that always sickens me.
At first I can’t find it, and for a brief moment my spirits lift. Is the table gone? Finally out of date? No. There it is: Table 17-6. Average Survival of Patients With Breast Cancer by Stage.
It hasn’t changed a bit. Patients with breast cancer like mine, Stage IIA, still have a five-year survival rate of 70 percent (not great, but O.K.) and a 10-year rate of 50 percent (not good at all).
My fixation with numbers like these dates back to even before my diagnosis.
When my doctor first measures the lump in my breast at 4.5 centimeters, I immediately pull out my mental slide rule. Breast cancer grows a centimeter a year, I remind myself. I had a normal mammogram two years earlier. Ergo, my four-centimeter lump cannot becancer. Q.E.D.
An ultrasound (much more accurate than my doctor’s tape measure) measures the lump at 2.5 centimeters and quickly disproves my “too big to be cancer” theory. My unhappiness grows exponentially: Not only can it be cancer, but if it is, it’s Stage II (tumors larger than two centimeters) with an average 10-year survival of 50 percent, assuming I have no cancerous lymph nodes. With cancerous nodes, my chance of living 10 years drops to 40 percent. Not even a 50-50 chance of seeing my 10-year-old daughter graduate from college.
My surgeon biopsies the lump, and I await the results with a mixture of apprehension and optimism. I now suspect that it is cancer. But dredging deep through my vault of old science concepts, I find hope. Using terms like “standard error of measurement” and “Heisenberg uncertainty principle,” I cobble together a new theory hinging on the fact that the tape measurement of my lump was so inaccurate. If the tape measure could be hugely wrong, I reason, the ultrasound could be a little wrong. After all, it need only be about a half-centimeter wrong to plunk me into Stage I, with its glorious 85 percent five-year survival rate.
The biopsy settles one question. My lump is indeed cancer. But then the numbers get worse: An M.R.I. sizes the tumor at 2.9 centimeters. My uncertainty theory works, it turns out, but Heisenberg has led me in the wrong direction.
Now my doctor is worried that I might not meet the three-centimeter cutoff for the newfangled radiation she has planned for me after surgery, where they implant a catheter in your breast and radiate from within. This allows for a much shorter course of treatment — one week instead of six. The gold standard, the Greenwich Mean Time of tumor sizing, is the surgical pathology report: the pathologist’s measurement of the actual tumor after it is surgically removed.
The lumpectomy goes well. The lymph nodes are clear. I go home to rest and heal and wait for the pathology report. When my doctor calls, I chant silently (less than two, less than two, less than two) as she reads the report to me. “Two point two centimeters,” she finishes enthusiastically. “Even better than I expected!”
I swallow as I search for a response. All I can think is: a 50-50 chance I’ll see my daughter graduate.
“Yeah,” I manage, “the only thing better would be if it were less than two centimeters.”
“Well, of course,” she answers, “but after that M.R.I., I was worried that it would be bigger than three and that you’d have to go through six weeks of radiation.”
“Right,” I mumble, spurning the lovely gift she has gone to so much trouble to give me.
It’s another two weeks before my next appointment, two weeks spent picking at the numbers as if they were ragged cuticles and searching through every available textbook for a table with more comforting statistics. I find none.
When I see her, I explain about the table and my 50-50 chance of attending my daughter’s graduation.
“But that’s not you,” she reassures. “Those numbers include people with much nastier tumors and much bigger tumors than yours. You are going to do fine.
“You,” she says, “will see your daughter graduate from high school. You’ll see her graduate from college. And you will be there when she defends her dissertation.”
I trust this woman, even beyond the trust automatically engendered when someone cuts you open, takes something out and sews you back up. She has always been honest, and her predictions, thus far, have all been correct. So I am looking forward to attending many graduations, wherever and whenever they may be. I’ve written them on my mental calendar in permanent ink.
But I can’t help myself. I still go straight to the index of every new textbook hoping I’ll find, one day, that the tables have turned.
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