Conno Christou does not leave things to chance. He tracks his sleep with a Whoop band, cross-references it with an Oura ring, and has nearly 100 biomarkers checked each year. He had done the annual blood work for four consecutive years, following the protocols of long-term researchers such as Peter Attia and Rhonda Patrick. He optimized his nutritional supplements, his circadian rhythm, his protein intake.
At 35, building his second company, he was as interested in the latest in health research as anyone he knew. His last check, in 2025, was green across the board. “It was the best I’d had in years,” he says.
Then after a workout, his arm swelled.
He didn’t think much of it at first. A week passed before he saw a doctor, who found two blood clots in his veins and planned surgery. But the pre-op exams changed everything. A doctor walked back into the room and told him the procedure was not happening.
“We see an 11 x 11 x 8 centimeter mass behind your sternum,” the doctor said.
A biopsy confirmed what Christou had never considered before. He had an aggressive, fast-growing form of non-Hodgkin’s lymphoma – a rare diagnosis that affects about one in 420,000 people, caused by a random genetic mutation unrelated to lifestyle, diet or stress.
The tumor had only been around for about three months. In three more weeks it would have reached stage four.
“Lucky in my bad luck,” Christou told this editor this week from his home in Athens, where he lives part-time. “It was only found because I advocated something completely different.”
What followed was an education in the limits of the medical system and in what a determined patient can do about it with tools now available.
His first oncologist, a renowned specialist, recommended the lighter of two available chemotherapy regimens. Christou booked his first infusion three days out. Then, the night before, he sought a second opinion.
The other doctor did not hesitate. He recommended the harsher regimen—continuous infusion in the hospital, cycling every three weeks for six months—referring to Christou’s specific pathology. The lighter treatment had about a 60% success rate for his presentation. The aggressive brought that number to about 85%. Two world-class doctors. Diametrically opposite recommendations.
“As founders, we hold the wheel,” Christou says of many people’s tendency to accept what they’re told—and why more shouldn’t. “You hear a lot of things. You don’t have to follow the first advice.”
He also didn’t choose to just follow the other doctor’s advice. Over the next two days, he gathered a total of 12 opinions — drawing on his professional network, reaching out to hematologists and oncologists in the United States and abroad, and calling for any favors he could. Eleven to one voted for the tougher path. He took it. The decision, he says, didn’t feel brave so much as logical. He was already a data-driven person, and now the effort felt existential to him.
Over six months of treatment, Christou approached chemotherapy as he approached building a business, like a marathon of sprints – each with a limited cycle and each week filled with data points. He had served a mandatory 25-month military service in Cyprus at the age of 18, and he also borrowed from that experience. He would make a good soldier, he told himself. Trust the process. Six cycles. Get through it.
He wore his Whoop throughout and found it remarkably accurate at predicting the days when his immune system would bottom out, sometimes feeling them before symptoms arrived. He kept a symptom journal using voice transcription, logging every shift, every side effect, every medication and antidote. He narrowed his focus to three variables: sleep, nutrition and, above all, psychology. (“That moves the needle more than anything else,” Christou said. “I never asked ‘why me’ — not once. That question has no useful answer.”)
He fed it all—blood results, scan data, wearable output, journal entries—into Claude. He is far from alone in turning to chatbots for medical guidance. A public opinion poll released in March found that a third of American adults now use them for health information and advice. The stories accumulating online suggest that for some patients, AI is delivering what the system could not.
Experts urge caution; Danielle Bitterman, clinical director of data science and AI at Mass General Brigham, has told the New York Times in recent months that general-purpose chatbots are often wrong and “have not been thoroughly evaluated” for personalized diagnoses.
Christou does not disagree. “It didn’t replace the doctors,” he says, but it “helps me ask the right questions.”
For a condition as rare as his — one an oncologist might see once a year — accessing a model that had absorbed the entirety of the medical literature was simply not the same as a Google search.
The model proved to be critical at the end of treatment. His last PET scan — the imaging used to detect active disease — came back equivocal. His oncologist began discussing another line of treatment, potentially radiation therapy, near his heart and lungs. It was an alarming development.
Christou did his homework again. He read that for this specific lymphoma, the false-positive rate on PET scans at the end of treatment is about 60%—a statistic that still amazes him. “It’s 2026,” he says. “Fifty percent.”
He fed all three of his PET scans and his MRI into Claude, which flagged a well-known but easily overlooked phenomenon: In patients under 40 recovering from this type of lymphoma, the thymus gland can be reactivated after chemotherapy, showing up on imaging as what appears to be active disease. Given his age, his specific scan characteristics, the model put the probability of this explanation at around 90%.
He sought three more opinions. The fourth doctor confirmed it: Thymus rebound. There was no active disease. No radiation therapy was necessary. He was ready.
Christou is still unfolding what the last year has meant to his health, how he works and how he thinks about time. He built Keragon, his current company, before any of this happened; it is an AI-powered platform that helps medical practices automate their administrative operations.
But going through the system as a patient has given him a new perspective. He saw nurses and doctors buried under tasks that had nothing to do with care. He received the same chemotherapy protocol as an 80-year-old woman, the side effects managed through a cascading chain of additional drugs, each causing their own problems. He says he’s sure we’ll look back on this era of treatment and creep.
He mostly takes Sundays off now. He tries to be present — at lunch with friends, at home with his dog, in conversations that once might have felt like a distraction from work. A VC friend told him some years ago that he said he kept playing again during treatment: Be happy now. He says it’s among the hardest things to do, and yet he’s finally appreciating its importance.
He says he would be happy to talk to anyone going through something similar to share notes, compare experiences. He seems to think so.
“It won’t happen in 10 years,” he says of what AI can already do for patients willing to use it. “It’s happening today.”
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