Conno Christou does not leave things to chance. It tracks your sleep with a Whoop band, compares it to an Oura ring, and monitors nearly 100 biomarkers each year. He had been doing annual blood tests for four consecutive years, following protocols from longevity researchers like Peter Attia and Rhonda Patrick. He was optimizing his supplements, his circadian rhythm, his protein intake.
At age 35, when he was building his second company, he was as interested in the latest health research as anyone he knew. Its last checkup, in 2025, was green across the board. “It was the best I’d had in years,” he says.
Then, after exercising, his arm swelled.
At first he didn’t give it much importance. A week passed before he saw a doctor, who found two blood clots in his veins and scheduled surgery. But preoperative exams changed everything. A doctor returned to the room and told him the procedure was not being performed.
“We see an 11 by 11 by 8 centimeter mass behind the breastbone,” the doctor said.
A biopsy confirmed what Christou had never before contemplated. She had an aggressive, fast-growing form of non-Hodgkin 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 had only existed for about three months. In three more weeks, he would have reached the fourth stage.
“Lucky in my bad luck,” Christou told this editor this week from his home in Athens, where he lives part-time. “I only found it because I was looking for something completely different.”
What followed was an education about the limits of the medical system and what a given 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 booked his first infusion three days in advance. Then, the night before, he sought a second opinion.
That second doctor did not hesitate. He recommended the harshest regimen (continuous hospital infusion, cycles every three weeks for six months), citing Christou’s specific pathology. The lighter treatment had approximately a 60% success rate upon presentation. Aggressiveness brought that figure to around 85%. Two world-class doctors. Diametrically opposite recommendations.
“As founders, we drive the wheel,” Christou says of many people’s propensity to accept what they’re told, and why many more shouldn’t. “You hear a lot of things. It is not necessary to follow the first advice.”
Nor did he choose to simply follow the second doctor’s advice. Over the next two days, he gathered 12 opinions in total, tapping into his professional network, contacting hematologists and oncologists in the United States and abroad, calling in every favor he could. Eleven votes to one voted in favor of the harshest path. He took it. The decision, he says, did not seem so brave as logical. He was already a data-driven person and now the stakes seemed existential to him.
During six months of treatment, Christou approached chemotherapy the same way he approached starting a company, like a marathon of sprints, each with a finite cycle and each week filled with data points. He had completed a 25-month mandatory military service in Cyprus at the age of 18 and put that experience to good use as well. It was said that he was going to be a good soldier. Trust the process. Six cycles. Get over it.
He used his Whoop at all times and found it remarkably accurate in predicting the days when his immune system would bottom out, sometimes signaling them before symptoms arrived. He kept a symptom diary using voice transcription, recording every shift, every side effect, every medication and countermedication. He narrowed his focus to three variables: sleep, nutrition and, above all, psychology. (“It moves the needle more than anything,” Christou said. “I never asked ‘why me,’ not once. That question has no useful answer.”)
He fed everything – blood results, scan data, handheld results, diary entries – to Claude. He’s not the only one turning to chatbots for medical guidance. TO public opinion survey published in March found that a third of American adults now use them for health information and advice. He stories Accumulated online data suggests that, for some patients, AI is delivering what the system was unable to.
Experts urge caution; Danielle Bitterman, clinical leader of data science and artificial intelligence at Mass General Brigham, told the New York Times in recent months that general-purpose chatbots are frequently wrong and “have not been thoroughly evaluated” for personalized 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), access to a model that had absorbed the entire body of medical literature was, he says, simply not the same as a Google search.
The model was critical at the end of the treatment. His final PET scan (the image used to detect active disease) was ambiguous. His oncologist began discussing a second line of therapy, potentially radiation therapy, near his heart and lungs. It was an alarming event.
Christou went back to doing his homework. He read that for this specific lymphoma, the false-positive rate on PET scans at the end of treatment is around 60%, a statistic that still surprises him. “We are in 2026,” he says. “Sixty percent.”
He introduced Claude to his three PET scans and his MRI, which pointed out a known but easily overlooked phenomenon: in patients under 40 recovering from this type of lymphoma, the thymus gland can reactivate after chemotherapy, appearing on images as what appears to be active disease. Given his age and specific scanning characteristics, the model places the probability of that explanation at approximately 90%.
He sought three more opinions. The fourth doctor confirmed it: thymus rebound. There was no active disease. No radiotherapy was necessary. He was clear.
Christou is still reeling off what the last year has meant for his health, the way he works, and the way he thinks about time. He built Keragon, his current company, before any of this happened; is an artificial intelligence-powered platform that helps medical offices automate their administrative operations.
But going through the system as a patient has given him a new perspective. He observed nurses and doctors buried in tasks that had nothing to do with care. She received the same chemotherapy protocol as an 80-year-old woman, and side effects were controlled by a cascading chain of additional medications, each causing its own problems. He says he is sure we will remember this era of treatment and shame.
Now he takes Sundays off, especially. Try to be present: at lunch with friends, at home with your dog, in conversations that once would have seemed like a distraction from work. A VC friend told him something years ago that he said he kept repeating during treatment: Be happy now. He says it’s one of the hardest things to do, and yet he finally appreciates its importance.
He says he would be happy to talk to anyone going through something similar to share notes and compare experiences. It seems like he means it.
“This 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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