In January 2021, Mathematician Hannah Fry was diagnosed with cervical cancer. When she received her diagnosis, an oncologist told her that her cancer had already reached stage 3 and it was still uncertain if it had spread to her lymph nodes. If not, Fry’s odds of survival were 90% for her. But if the infection had spread, the odds of that were about 60%. “It looked like she had cancer in four of her lymph nodes, but I wasn’t entirely sure,” she says. “The surgeons decided to perform a very radical and aggressive operation. They effectively removed about a third of my abdomen.”
Fry was clearly concerned, but he also struggled with calculating the risks involved in deciding whether to undergo certain cancer treatments. “These are not good treatments. They have life-changing effects,” she says. “When you have cancer, you are fighting an invisible enemy that may or may not exist. Even if it does, it may or may not pose a real threat.”
This claim is supported by evidence. For example, in the 1970s a group of Danish pathologists performed autopsies on 77 women who had recently died. They had died from various causes, including heart attacks and car accidents, and had never been diagnosed with cancer. The researchers performed a double mastectomy to look for signs of cancer and found abnormal tissue, either cancerous or precancerous, in about 25 percent of the group. “This is an amazing result,” Fry says. “This experiment was repeated many times for all types of cancer, including prostate cancer and thyroid cancer. 7 to 9 percent of people are wandering around with cancer they never knew they had.”
This statistic sounds terrifying, but Fry interprets it differently. This is only about 10 times the number of people who will eventually be diagnosed with cancer. “What this means is that most of the time, our bodies are actually pretty good at finding cancer cells, killing them, and getting rid of them,” she says. “Even if our bodies can’t cope with it, cancer often grows so slowly that we die from other diseases.”
In another study, researchers surveyed about 1,600 men diagnosed with prostate cancer. This cohort was divided into his three groups, one undergoing surgery, another of his undergoing radiation therapy, and a third undergoing no medical intervention, instead undergoing regular monitoring. received. “At the end of the study, after several years, there was no difference in overall survival,” Fry says. “Still, those who underwent medical intervention were left with erectile dysfunction, incontinence, bowel problems, and other problems due to radiation therapy.” We investigated the effect of national screening programs on mortality. The conclusion was the same. Mortality remained the same despite an increase in the number of diagnoses and treatments.
Fry recalls visiting a cancer clinic during treatment. There she met a woman in her mid-sixties who had just had a lump removed from her breast. Her oncologist explained her options to her, and although she had all of her detectable cancerous tissue removed, she said there was always the chance that she would come back and could be incurable after that. explained. Her doctor then gave her two options: to continue her chemotherapy or stop her treatment. Her odds of survival were already very high at 84%. Statistically, treatment only increases her chances of that happening 4%. “She was obviously very scared,” Fry says. “She said to me, ‘Okay, I thought about it. I’m going to get chemo. If she doesn’t, she’s going to die.'” Fry was stunned. Was enduring such harsh treatment worth the modest improvement in survival?
Fry understands that when faced with a dreaded cancer diagnosis, it is often difficult to make rational decisions based on statistical considerations. She had to go through the same decision process. And although she considers herself one of the lucky ones, although her treatments have kept her disease-free for nearly two years, she is now suffering from lymphoma, a chronic condition that causes her lower extremities to swell. Suffering from edema. “I didn’t know it at the time, but I was taking a very risk-free route that I didn’t need,” she says. “I don’t really regret it. It just feels like the math was done without giving me a chance to put into the equation what I really care about.”
This article appeared in the July/August 2023 issue of WIRED UK magazine.
