Updated March 2025 to maintain the latest information in treatment and research.
An interview with Tomoaki Kato, MD, Chief of the Division of Abdominal Organ Transplantation; Surgical Director of Liver and Gastrointestinal Transplantation; and Executive Director of the Columbia Transplant Initiative.
A Changing Landscape In Liver Care
What’s new in the treatment of liver disease?
Well, the huge change is viral hepatitis treatment. Hepatitis C used to be a poor target for transplant, but now it's a totally different story; things have really transformed since new medications for hepatitis C have been discovered. It is no longer a threat—we have a cure.
I started doing liver transplants in 1995, and from then until just recently, it was the same terrible story—a patient with hepatitis C would have a liver transplant but end up with recurrence. And it goes so quickly, then the patient ends up dying of it. We would try to do a second transplant, but the results were universally poor with hepatitis C. Recurrence happened in pretty much everybody, and in some, it happened violently.
How has the medication changed things? Is this something you would take before and potentially after transplant?
It’s called a Direct Antiviral Agent (DAA), a very simple name. All we do is give it for six to 12 months, and that’s it—it cures the hepatitis. And if they recur, now we use the medicine. It's now almost like a minor infection.
But the medicine is still quite expensive, so we have to do a lot of preparation for that. So far, everybody who has a hepatitis-C-positive liver ends up being treated, and we haven’t really heard of any case of recurring hepatitis C being untreatable. It's changed a lot of our patients’ lives. Hepatitis C may actually go away—at some point, you may no longer need liver transplant for hepatitis C because of this medication.
Does that mean you are seeing fewer patients in need of liver transplants overall?
Well, no. We all thought, “Now that hepatitis C can be cured, there's no longer such a need for transplant,” but that was not the case.
Very interestingly, right around the same time that hepatitis C got a cure, the population shifted much more towards obesity-related liver disease. It’s now called metabolic dysfunction-associated steatotic liver disease (MASLD)—which recently replaced the name Nonalcoholic fatty liver disease (NAFLD). It’s a disease that causes excess fat to be stored in the liver. So, fatty liver disease has started to become the main indication for liver transplant, along with alcoholic liver disease.
The problem has been more of an issue in the past 20 years than the previous 20 years, as the entire country has become more obese, and those people are getting older. Obesity in young individuals doesn’t necessarily damage their livers early on, but after some time, they can have cirrhosis of the liver and can also develop cancer from that. It’s really the biggest change we’ve seen in the last few years aside from the cure of hepatitis C.
The Liver Cancer Conundrum
Has the rise in MASLD also created an increase in liver cancer?
You know, it’s possible, but we have not drawn a direct line. But there is an alarming upward trend of liver cancer, hepatocellular carcinoma (HCC), in the United States. A lot of cancer-related deaths are going down, like breast cancer, lung cancer…all the major cancers in the U.S. show a decreasing trend for cancer-related mortality. The only one that keeps going up is liver cancer. Liver cancer-related mortality has not gone down at all. With that, incidence of liver cancer is going up, liver cancer that is not curable, is going up.
What are some other causes of this rise in liver cancer?
That’s a good question. Some part is definitely the growing immigrant population from Asia; Chinese immigrants have a higher incidence of liver cancer, so that's a big factor. But I don't think that's the only thing that explains it. There must be some overall incidence increase in other populations because there hasn’t been that much of a shift within the Asian population over the last 10 years. You know, the growing Asian population alone doesn’t explain the rise in liver cancer-related mortality.
Hepatitis C was the main reason for liver cancer for a long time. Now that hepatitis C is going down so rapidly, how do you really explain the increased incidents? I’m curious to know, really. Maybe it is still a leftover problem because even if hepatitis C is cured, those who suffered from it for a long time can still develop cancer.
Do you think this current upward trend of liver cancer will continue to rise?
Maybe over the next few years to 10 years, the cancer incidence could start to go down, but it's not the case right now. We used to say liver cancer only happened in cirrhosis, hepatitis C, hepatitis B, but lately, we've been seeing non-cirrhotic, non-hepatitis liver cancers as well.
So, there may be some specific increasing trend there. The liver cancer increase is clear. If you look at the National Cancer Database, liver cancer is really the highest, and it’s going up; in women, it is increasing by 3 percent per year. And liver cancers are really bad—they’re fatal, you know?
Treating MASLD and Alcoholic Liver Disease
Let’s talk about other treatments for MASLD besides transplant. Is there anything new we should know about?
You know, treating liver disease, developing ways to deal with it has been a struggle. There are some medications for fatty liver disease in clinical trials that have been ongoing, but it takes a long time to really prove the effect. Treating fatty liver and the problems with it, there isn’t a ‘one treatment’ fix-all. It’s related to habit, psychology, and chemistry. MASLD is based on obesity, and obesity is not just treated with medicine.
So, this requires a wider scope of treatment strategy compared to hepatitis C, with just one-anti-viral-kills-everything type of idea.
How do you think we change our approach? Have you seen a shift in strategy yet?
Not yet as a society, but there are a lot of preventative medicine ideas starting to gain popularity in areas like cardiovascular disease prevention, hypertension prevention, and diabetes prevention. Exploring strategies to modify behavior or modify diet to change the outcome—fatty liver disease may fall into that category. The way to prevent fatty liver from happening should start right from the get-go: when you're a child.
You know, it doesn't become a real problem until after your 50s or 60s. But all those fatty livers may have been there since childhood, right? So, starting with teenage obesity is how to really prevent that—really fix the problem before it becomes liver disease with preventative medicine and preventative health, diet, and nutrition.
What about treatments for alcoholic liver disease? How does it differ?
Treating liver disease in an acute alcohol-related liver issue is changing. It used to be that those patients were rejected for liver transplant upfront; we didn’t really treat them. But recently, we started opening the door. It’s very important that we do. Equity in access is critical, and to make judgments on who gets a liver and who does not when we have such a shortage cannot be without thought.
Alcoholism is a real disease, and we believe everybody deserves a chance. But the larger crisis is that there are not enough livers for everybody. We need more organ donors, especially in New York. Everyone should be an organ donor.
There's a sort of landmark publication of a French study that showed that with acute alcohol liver problems, if you select the patient really well, they could do really well—those ready to stop drinking alcohol, stop destroying their liver. But family support is really important, and the patient has to be willing to cope with the medical system too and rehab prevention. In that French study, if you select those patients for liver transplant carefully and include a relapse prevention program, they tend to do well.
Advances in Living Liver Donation
Tell us about the Living Liver Donation Program.
Columbia is one of the biggest centers for living donor liver transplant in the country, both adults and children. It was started here over 30 years ago. We did the first-ever living donor transplant in the United States. The patient is still doing really well. So that really means something—the first one ever done in the country is still doing so well.
We now do it laparoscopically and now for all donors robotically. Let’s start with kids because it’s a little bit different from adults. Living liver donation is when an adult gives a small piece of liver to transplant into a child. And it's not as complicated as many people think. Their liver grows back to normal size in a couple of months. Donors don’t need medication afterward, either.
Columbia has the largest robotic living donor hepatectomy program in the country. We want to establish living liver donation as a standard of care in children, and we're greatly expanding the use of it in adults too.
In adults, deceased liver availability is not as bad, so living liver transplant haven’t been as common. In the past, it’s been a bit harder to do living donation in adults because of size. Children only need a small piece of the liver, but adults need a much bigger piece. But that’s changing. At Columbia, we have Dr. [Jason] Hawksworth, a leader in robotic liver surgery. Our program now does all donors robotically. And outcomes are excellent.
Could living liver transplantation advance or be refined even further?
Yes, certainly. We’ve begun developing a tolerance protocol for living donor liver transplant. The goal is to eliminate the need for lifelong immunosuppressive medication. It’s not quite there yet, but it’s an exciting direction.
The Next Frontier: Xenotransplantation
Xenotransplantation is something we’re hearing more about lately. What role could it play in liver transplantation?
So, this is still early, especially for the liver. But, yes, I think this will be very important in the near future. We are looking at this as a kind of bridge, especially for patients with liver tumors who are not transplant candidates right now. If we can use a pig liver—even short term—that may give the patient time. And time is very important. Time to try other therapies. Maybe time to wait for a human liver. Time to live longer. That’s really the idea.
What kind of patient are you thinking about? What situation?
Right—so, for example, a patient with a large liver tumor that doesn’t meet transplant criteria. No other treatment is working. In that case, maybe we can use a pig liver. Not forever, but enough time to stabilize, maybe even shrink the tumor, or prepare for transplant later. It’s not standard yet, but it’s a very new idea to expand care. And this kind of thinking is needed in oncology.
What are the main challenges, especially with the liver?
Well, the immune system, always. The pig is very different from a human, so the rejection happens right away unless you prepare carefully. That’s why we are working closely with immunologists. Dr. Sykes and her team have been studying this for many years. We use a special pig just for this purpose. They are genetically modified to reduce rejection, and we’re trying ways to train the immune system to accept them.
One way is to transplant thymus tissue together with the liver. Another way is to give the donor bone marrow. It’s called mixed chimerism. The immune system sees the organ and says, “Okay, this is part of me.” We’ve seen success in the animal models already, so we are hopeful.
Do you think we will see this in patients soon?
For heart, yes. That work is already moving toward clinical trial. For the liver, maybe not yet. But we are preparing. Maybe not in five years, but I think it’s possible in ten. We are moving step by step.
We have already seen long survival with pig kidneys in primates. That is a very big step. The key will be to control rejection without too much immunosuppression. If we can do that, then we can start to talk about real clinical use.
What makes this kind of work exciting for you?
If we can solve the organ shortage—even partly—that changes everything. We’ve talked about shortage for many years. But now, we’re really doing things about it. We are getting close not just for liver, but for all organs. It’s very exciting.
A Tool for the “Inoperable”: Ex Vivo Surgery
Another exciting topic, let’s talk ex vivo—What is ex vivo surgery?
Ex Vivo means ‘out of the body’. So, in any ex vivo surgery, the organ is taken out of the body and then put in a cold preservation solution. Then, after the tumor is removed from the organ, we put the organ back in. Sometimes we do as many as six abdominal organs in one surgery.
The reason why it's necessary is that the tumor is on the blood vessel. If you just take the tumor out, the blood vessel will be cut, and blood supply would be shut off. And the organ needs the blood supply. But if you remove the tumor in a preservation solution, an organ can still survive while we are taking the tumor out.
Since we began the program in 2008, we’ve completed around 50 ex vivo surgeries. These are extreme cases—situations where traditional surgeries aren’t possible. So this surgery is really an expansion of care. It’s another tool in the toolbox, and I think it’s important for the medical community and for patients to know that it exists.
Has the ex vivo surgery changed at all since you started? Has patient selection changed?
Yes, we’ve learned a lot. What really matters is tumor biology. Ex vivo works especially well in patients with low-grade tumors—people who couldn’t get another surgery because the area or location of the tumors made it impossible to resect. If the tumor biology is bad, the outcome is still bad. But if the biology is good, the outcome is good.
So, we’ve refined and fine-tuned the technology. We’ve divided our 45+ cases into several groups, and in the low-grade to benign cases, the outcomes were excellent. That proves the concept—the surgery itself works.
Even in malignant cases, very bad ones, we have some long-term survivors. That tells us ex vivo can still work in the right cases. It’s just like in pancreas or bowel cancer surgery: long-term survival is rare, but it’s not zero. Some patients are cured.
What does that mean when you say you're refining the technology?
We’re working on selecting the right tumors and the right patients. Some locations make ex vivo easier. Others are so challenging that, even with the technology, the risk may be too high. So the patient's physical shape matters too.
We’ve also been collaborating more closely across specialties—transplant oncology, immunology, and hepatobiliary surgery—to refine the approach and evaluate outcomes. That’s part of the mission of the Columbia Transplant Initiative (CTI): to combine clinical experience with research to push the field forward across transplant, not just liver. We are all working together, heart, lungs, kidney, liver…Our goal now is to advance the field and expand access to it safely.
Making Liver Transplants Accessible to More People
There are large racial disparities in access to liver transplant. How is the Columbia Transplant Initiative working to address this?
This is a matter of health justice. There are known disparities in access to liver transplantation. Studies show that Black patients and Asian patients, other minorities, are less likely to undergo liver transplant than white patients.
And with HCC [Hepatocellular Carcinoma], for example, these are curative therapies. We started the Black Liver Initiative to determine exactly what causes those disparities and how we will fix it. We also have the Asian Liver Initiative. And now we have a work group through CTI that focuses on these disparities specifically, from a research perspective, surgery, access and inclusion. That’s not just on the patient side; we need all of our patients represented in their care teams. We must reflect who we serve.
Even now, cultural sensitivity in evaluation is lacking. If English isn’t your first language—even if you have a translator—it’s not like the language-capable people are doing the evaluations. That can create barriers and misunderstandings.
Liver transplants must serve everybody equally. That’s our responsibility.
Looking Ahead
What are you optimistic about the future of liver care?
We are in the fine-tuning stage of liver transplant technology. But I’m very optimistic about the potential expansion of liver transplant for cancer treatment—transplant oncology. And I think xenotransplantation, maybe 10 years from now, could solve the liver shortage. Also, we’re on the edge of eliminating the need for immunosuppression after transplant.
The future of liver transplant will be shaped by these innovations—but also by access and inclusion. That’s what we’re working toward at Columbia, through CTI, but also basic patient care, education, research, collaborations. We want to change the way these diseases have been viewed in the culture and advance the way we treat them so that everyone has access to an organ when they need it.
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