Kono Christou does not leave things to chance. He tracks his sleep with a Whoop band, crosses it with an Oura ring, and has nearly 100 biomarkers tested every year. She did the annual blood draw for four years in a row, following the protocols of longevity researchers like Peter Attia and Rhonda Patrick. He was optimizing his supplements, his circadian rhythm, his protein intake.
At 35, he built his second company, was just as invited to the latest health research as anyone he knew. His last checkup, in 2025, was green. “It was the best I’ve had in years,” he says.
Then, after a workout, his hand swelled up.
He didn’t think much of it at first. It was a week before he saw a doctor, who found two blood clots in his veins and scheduled surgery. But the preliminary exams changed everything. A doctor came back into the room and told him that the procedure was not happening.
“We see an 11 by 11 by 8 centimeter mass behind your sternum,” the doctor said.
A biopsy confirmed what Christou had never even 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 with no connection to lifestyle, diet or stress.
The tumor was only there for about three months. In three more weeks, he would have reached stage four.
“Lucky in my misfortune,” Christou told this editor this week from his home in Athens, where he lives part-time. “Only found because I went in for something else entirely.”
What followed was an education in the limits of the medical system and what a determined patient can do about it with the tools now available.
His first oncologist, a renowned specialist, recommended the lighter of the two chemotherapy regimens available. Christou stopped his first infusion for three days. Then, the night before, he asked for a second opinion.
The second doctor didn’t hesitate. He recommended the harshest regimen—continuous in-hospital infusion, cycling every three weeks over six months—citing Christos’ specific pathology. The lighter treatment had about a 60% success rate for his presentation. The striker brought that number to around 85%. Two world class doctors. Diametrically opposed recommendations.
“As founders, we hold the wheel,” Christou says of many people’s tendency to accept what they’re told — and why not more. “You hear a lot of things. You don’t have to follow the first tip.”
He didn’t choose to just follow the second 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 U.S. and abroad, asking for every favor he could. Eleven to one voted for the harder road. He got it. The decision, he says, was not so much brave as logical. He was already a data-driven person, and now the stakes seemed existential.
Over six months of treatment, Christou approached chemotherapy the way he approaches building a company, as a marathon sprint — each one with a finite cycle and each week filled with data points. He had done mandatory 25-month military service in Cyprus at the age of 18 and borrowed from that experience as well. He would make a good soldier, he told himself. Trust the process. Six circles. Pass it on.
He wore his Whoop throughout and found it remarkably accurate at predicting the days his immune system would go down, sometimes noting them before symptoms came. She kept a symptom diary using voice transcription, recording every shift, every side effect, every drug and antidote. He narrowed his focus to three variables: sleep, nutrition, and, first and foremost, psychology. (“It moves the needle more than anything else,” Christou said. “I never asked ‘why me’ — not once. That question has no useful answer.”)
She gave everything—blood results, scan data, wearable results, diary entries—to Claude. He’s not 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 The backlash online suggests that for some patients, AI is offering what the system couldn’t.
Experts advise caution. Danielle Bitterman, clinical lead for data science and artificial intelligence at Mass General Brigham, told The New York Times in recent months that general-purpose chatbots are often wrong and “not thoroughly evaluated” for individualized diagnoses.
Christou does not disagree. “It didn’t replace doctors,” he says, but “it helped me ask the right questions.”
For a condition as rare as his—one that an oncologist might see once a year—accessing a model that had absorbed the entire body of medical literature wasn’t, he says, just the same as a Google search.
The model proved critical at the end of treatment. His latest PET scan — the imaging used to detect active disease — came back equivocal. His oncologist began discussing a second line of treatment, possibly radiation therapy, near his heart and lungs. It was a worrying development.
Christou did his homework again. He read that for this particular 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. “Sixty percent.”
He gave all three PET scans and an MRI to Claude, which pointed out a well-known but easily overlooked phenomenon: in patients under 40 recovering from this type of lymphoma, the thymus gland can reactivate after chemotherapy, appearing on imaging as active disease. Given its age, its special scanning characteristics, the model put the likelihood of this explanation at around 90%.
He sought three other opinions. The fourth doctor confirmed it: thymus recovery. There was no active disease. No radiation therapy was needed. He was clear.
Christou still unfolds what the last year means for his health, how he works and how he thinks about time. He built Keragon, his current company, before any of that happened. is an AI-powered platform that helps medical practices automate their administrative functions.
But going through the system as a patient gave him new perspective. She watched nurses and doctors get buried under tasks that had nothing to do with care. She received the same chemotherapy protocol as an 80-year-old woman, with the side effects managed through a cascading chain of additional drugs, each causing its own problems. He says he’s sure we’ll look back on this season of healing and creepiness.
He takes Sundays off now, mostly. 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 friend of VC’s told him something years ago that he said he kept playing during treatment: Be happy now. He says it’s one of the hardest things to do and yet he ultimately appreciates its importance.
He says he’d be happy to talk to anyone going through something similar to share notes, compare experiences. He seems to mean it.
“It won’t happen in 10 years,” he says of what AI can already do for patients who want to use it. “It’s happening today.”
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