I want to put an end to the phrase "there is no treatment." Standing beside patients, opening new paths in medicine

2026/08/13

In March 2026, cryotablation for lung cancer was approved for coverage under Japan's national health insurance, and attention is also turning to a world-first surgical technique for tumors that invade the heart and great vessels. The driving force behind both is Professor Keisuke Asakura of the Department of Surgery (General Thoracic Surgery) at Keio University School of Medicine. Pursuing the right treatment for each individual patient, he has opened up new possibilities in medical care. We spoke with him about the starting point of his path to medicine, his convictions about medical care, and his outlook for the future.

What led Prof. Asakura to medicine, he says, was visiting Keio University Hospital as a patient when he was a child.

"It was my first time at a big hospital. It was also the first time I'd felt afraid of getting sick, and even as a kid I thought that if I were a doctor, I could help my family and friends."

The illness itself was not serious. But that experience is what first got him thinking about medicine as a career.

He is a thoracic surgeon now, but when he first entered the School of Medicine, he wanted to go into internal medicine.

"I thought the way surgeons work with their whole body looked cool. I played volleyball in high school and university, so the sports-team atmosphere appealed to me too."

Looking back on why he chose thoracic surgery, he says, "Thoracic surgery is technically demanding, and there are plenty of moments where things get dangerous. If anything, that's exactly why I wanted to do it. I'm the type who wants to take on the harder option."

Prof. Asakura graduated from the School of Medicine in 2002. He has built up a wide range of experience since then, but two of the biggest turning points were both periods spent outside Keio.

The first came in 2011: a domestic fellowship at Himeji Medical Center, a formal placement outside his own university.

At the time, thoracoscopic surgery (minimally invasive surgery performed through several small incisions in the chest) was starting to gain ground in Japan. Nine years out of medical school, Prof. Asakura saw the procedure presented at a conference and came away convinced that Keio should be doing it too.

He moved quickly.

"I emailed the doctor who'd given the presentation directly and asked if they would let me come and learn the procedure. They agreed to take me, and then I went to the head of my department and asked if I could go for a year. That's backward from how it's supposed to go, of course.” [laughs]

In that one year, he was lead surgeon on about 100 thoracoscopic surgeries.

"Learning a new procedure mattered a lot, obviously. But there was something I learned that mattered more."

What mattered more was teaching.

"When you're the one teaching, it's a really big decision to hand an operation to a young doctor who's only going to be there a year. If something goes wrong, the responsibility is yours. But you do it anyway, so the younger doctor gets the experience. That really earned my respect."

He says that year taught him how hard it is to keep surgical quality high while training the next generation—and how much both matter.

"Now that I'm the one teaching, that experience still shapes what I do. Keeping the quality of care high while making sure young doctors get real experience is something I think about constantly."

The second turning point was the three and a half years he spent at the National Cancer Center Hospital starting in 2015.

"Doctors come there from all over the country, and I experienced approaches to care and surgery that were completely different from anything I'd learned at Keio or Himeji."

Prof. Asakura says the biggest change was realizing that what he had taken as standard practice was not the only way.

"At Keio, you're taught to do things a certain way. But when you're at another hospital, you see that they do things differently and still get good results. That kind of experience made my thinking a lot more flexible."

That is precisely why he still encourages young doctors to spend time outside Keio, at least once.

"I say the same thing to the young doctors now: You should get out at least once. Other hospitals have their own ways of thinking, their own culture. Knowing that the Keio way isn't the whole picture is a real asset for a doctor."

Learning new techniques, training people, staying flexible enough to keep learning. All of that later fed into Prof. Asakura's belief: "provide the care you'd want to receive."

Prof. Asakura returned to Keio University Hospital in 2018 and was appointed professor in 2023. If he is to deliver the care he believes in, one idea matters more than any other in how he runs his department.

"Provide the care you'd want to receive."

The phrase is displayed on the General Thoracic Surgery website and in its publications, and Prof. Asakura repeats it to young doctors at case conferences.

"When I'm working out what treatment is genuinely right for a patient, I make a point of asking myself whether I'd want to receive this treatment, and what I'd do if it were my own family."

He thinks this way because every patient's circumstances are different.

"Clinical practice guidelines set out evidence-based treatments, but that doesn't mean you should always follow them to the letter. What's going on in a patient's life, how they think about it themselves, their family—none of that is in the guidelines. Sometimes you can't tell what's really best for someone until you put yourself in their position."

Of course, Prof. Asakura knows how hard it is to fully understand what someone else is feeling. Even so, he keeps asking himself the same question.

"If I were the patient… Coming back to that is what lets me recommend the right care."

All of this goes back to something much earlier: visiting the hospital as a patient when he was a child. He knows how anxious a patient can feel because he has felt it, which is why he thinks from their perspective—as he always has.

Prof. Asakura's pursuit of "care you'd want to receive" led him to cryoablation for lung cancer and other cancers of the chest. Cryoablation is a treatment in which a fine cryoprobe is passed through the skin to the lesion under CT guidance, then cooled at the tip to below minus 100 degrees Celsius, killing the cancer cells. It does not require a large incision in the chest, so it places less strain on the body.

"It's a treatment we can offer patients who can't have surgery, people who cannot tolerate further lung resection, or who aren't well enough for a general anesthetic."

It can also be repeated, and that matters just as much.

"Radiation therapy is excellent, but you generally can't irradiate the same site again and again. With cryoablation, you can repeat it as often as you need to, even if the cancer comes back in the same place."

The real significance of the treatment, he says, is that it gives an option to patients who until now have been told there is nothing more surgery can do, and that radiation would be difficult too.

At the same time, he is quick to say that none of this was his invention.

"I'm not the one who started this. Dr. Masafumi Kawamura, who was in our department then, and Dr. Seishi Nakatsuka in Diagnostic Radiology began it in 2002. I'd only just joined the department, and I came in as the most junior member of that group. The other thing is that we can only do this safely at Keio because of the exceptional skill of the interventional radiologists who place the needles."

Servicing problems with the equipment forced Keio to stop offering cryoablation in 2017. When Prof. Asakura returned from the National Cancer Center in 2018, the first thing he set out to do was start it up again.

"First we had to bring in the equipment. That alone was a major hurdle," he says.

Cryoablation equipment is expensive, and buying it was not simple. But he took the time to show the hospital why the treatment was needed, and with the leadership and the departments involved behind him, the equipment was approved.

There was a second obstacle.

At the time, cryoablation in the lung was not recognized as an insured treatment.

“If patients were going to have this treatment with any peace of mind, we had to get it running under the framework that lets an insured treatment be paired with one not yet approved in Japan.”

That took preparation across the hospital, above all with the Clinical and Translational Research Center. Treatment began in 2023 under Patient-Proposed Health Services, one route within that framework. All twenty cases authorized under the Patient-Proposed Health Services program were completed safely by January 2026. Separately, in March 2026, cryoablation for lung cancer was approved for insurance coverage.

Patients and medical professionals now come to Keio University Hospital from all over the country.

"Coverage isn't the finish line. The way I see it, our job now is to help cryoablation spread safely across the country."

The department already hosts doctors from hospitals around the country who come to observe the procedure, and its interventional radiologists have begun running training sessions and putting teaching materials together.

For all that, cryoablation has not changed what he believes.

"A lot of patients come to us asking for cryoablation. But it isn't always what's really best for them."

In practice, he often recommends conventional surgery or radiation instead.

"You don't recommend a treatment because it's the new one you're working on. You recommend what's right for the patient in front of you. That's the first principle."

That is why cryoablation is a new option for patients first and a new treatment second.

Cryoablation is not the only thing Prof. Asakura is working on.

He is also taking on new operations for cancers of the chest that have grown into the heart and great vessels. That work runs through the Center for Treatment of Tumors Invading the Aorta/the Vena Cava, the only one of its kind in Japan.

"The question I'm working on hasn't changed: How do we treat the patients that local therapy has never been able to cure? That's what I keep coming back to."

Local therapy means therapy aimed directly at the lesion itself: surgery, radiation therapy, cryoablation.

"Drug therapy works on the whole body, but I'm a surgeon. So I want to widen the group of patients local therapy can save. Pushing out the limits of what it can cure—I see that as my job."

That way of thinking produced something else as well: an operation for tumors that invade the heart and great vessels.

Once a cancer in the chest reaches behind the heart or deep around the aorta, a surgeon cannot get to it, and in most cases there is no choice but to give up on removing it.

So Prof. Asakura and his colleagues worked with others at the center, above all the cardiovascular surgeons, to devise a new operation.

"We were looking at the CT images together, going over how we could take it out safely. And one of the cardiovascular surgeons said: Why not cut the aorta, then put it back?"

Dividing the aorta brings the tumor behind it into view. With the tumor visible, the surgeon removes it, then reconnects the vessel.

"Cutting the aorta to open up the view is not something a thoracic surgeon would think of. But for cardiovascular surgeons it's something they do every day. We hit on that idea precisely because we come from different specialties."

The new operation means surgeons can now reach cases that were beyond them before. Other university hospitals now refer patients, and the team has successfully completed two cases—a world first—and published an international case report.

That kind of collaboration is possible, Prof. Asakura says, because of the way departments at Keio University Hospital work across their own boundaries.

"At Keio, the departments really do talk to each other. It isn't something General Thoracic Surgery does alone. Cardiovascular Surgery, Diagnostic Radiology, Anesthesiology, the Office of Patient Safety—when that many departments work together, we can take on difficult operations and new treatments like cryoablation”.

That matters most when the medicine is this complex. Surgical skill alone isn't enough. Safety management and the hospital's own review process count just as much.

"When we start a new treatment, the whole hospital checks it for safety as we go. Because so many departments are behind us, we can take on something new with confidence."

In recent years, Prof. Asakura has also taken up research using genome analysis and organoids, "mini-organs" grown in vitro from stem cells such as iPS cells, with a structure and function close to those of a real organ.

The aim is to analyze tumors removed in surgery and establish, scientifically, which patients actually benefit from an operation.

"It isn't that I want to operate on as many people as possible. What I want the research to show is which patients really benefit from surgery."

Whether he is developing a new technique or working out who it is right for, the goal is the same.

"Getting a new option to patients who previously had none. That's what my research is all about. Cryoablation, the new operation, the genome work—they're all means to that end.”

Prof. Asakura has one other priority in running his department:

making it possible for young doctors to pursue research that genuinely interests them.

"With research, I think the best thing is to work on what you find interesting."

Alongside his own research, the department runs many studies led by early-career doctors, and the subjects are wide-ranging—AI-assisted surgery, recovery after surgery in elderly patients, working with rehabilitation.

"When I ask myself why I grew so much in that one year at Himeji, I think in the end it was because I chose what I wanted to do, rather than doing what my boss told me to. So I want the people on my team working on the subjects they actually care about, in the clinic and in research alike."

Asked what words he lives by as a doctor, he answers at once: dokuritsu-jison, independence and self-respect.

"There are two meanings in it. One is thinking for yourself and taking responsibility for your actions. Not because someone told you, but because you thought it through and made a decision. I think that matters a lot."

The second meaning is respect for others.

"If I think and make decisions for myself, so does the person across from me. I respect that they think for themselves and make their own decisions. That is how I want to treat patients and younger doctors alike."

Lastly, when asked what he would say to high school students hoping to study at the School of Medicine, Prof. Asakura answers, "What Keio gives you is people. That is the real asset."

"The teaching and the research are excellent here, of course, but more than that, there is a culture of working across departments. And that network stays with you long after you graduate."

He saw that for himself last year, on a visit to Brazil with a group of medical students.

"We were on the other side of the world, and nearly thirty Keio graduates from other faculties, none of whom I had ever met, got together and threw us a welcome party. I remember being surprised that the Keio network reached that far."

Prof. Asakura will draw on those connections, help train the next generation, and bring new treatments to patients.

"I want to reach the patients who until now have had no treatment, and give them a new option."

For those patients, he keeps working.

Related information: Percutaneous cryoablation for lung cancer — a guide for patients (Japanese)： https://keiothorac.umin.jp/patient/guide/cryoablation.html

Keisuke Asakura

Professor, Department of Surgery (General Thoracic Surgery) Keio University School of Medicine

Vice Director, Keio University Hospital (Patient Safety, Center for Surgery and Angiography, Labor Management, Public Relations)

Keisuke Asakura graduated from Keio University School of Medicine in 2002 and joined the school’s Department of Surgery. He moved to General Thoracic Surgery at Himeji Medical Center in 2011, and to General Thoracic Surgery at the National Cancer Center Hospital in 2015. He returned to Keio as Senior Assistant Professor in the Department of Surgery (General Thoracic Surgery) in 2018, spent a period at St. James's University Hospital in the UK in 2022, and was appointed Professor in the same department at Keio in 2023.

*All affiliations and titles listed are those at the time of the interview.