A conversation with Sam Yoon, MD, Chief of the Division of Surgical Oncology and Vice Chair of Surgical Oncology Research and Education.
What is surgical oncology?
Surgical oncology is an area of expertise that focuses on the surgical treatment of various cancers.
As surgical oncologists, whatever disease you take care of, you have to know broadly about the disease, the natural history, the chemotherapy, the radiation. You have to understand the disease. For example, for gastric cancer, I need to know if should I give chemo first and then do surgery or do surgery and then chemo? What's the prognosis of the patient? You can't just have surgical expertise and know about the surgery. You have to know comprehensively about the care of the patient. You're not just the technician that's taking out the cancer.
You mentioned gastric cancer, is that the focus of your surgical oncology work?
My clinical expertise is in gastric cancer, sarcoma, and melanoma. That’s what I focus on in my practice. I did my general surgery residency at Mass General Hospital in Boston, then a surgical oncology fellowship at Memorial Sloan Kettering. I finished in 2003 and I've been doing cancer surgery for the past 18 years.
In terms of treatment timeline, when do you, a surgical oncologist, see patients? How does this surgical care differ?
Well, it varies by cancer. The main thing about surgical oncologists beyond the regular surgeon is that some of the surgeries require additional expertise. For example, for gastric cancer, 70 or 80 percent of gastric cancer in the United States is done by general surgeons who have really no specific expertise in gastric cancer.
The lymph node dissection for gastric cancer is fairly important. In Japan and Korea where they see a lot of gastric cancer, they do these extensive procedures called D2 lymphadenectomies where they take the first-tier lymph nodes and the second-tier lymph nodes. Their average node counts are 40 to 50 nodes for a specimen.
In the United States where general surgeons are taking out the stomach cancers, they're comfortable with taking the stomach part out and connecting it, but the second-tier lymph nodes are on these vessels that can bleed, so they often skimp on the nodal dissection. When you look at the national database, the average node count in the United States is about 10 or 15. My average is 42.
Sarcomas are even more complicated because they uncommon, occur throughout the body, there are over 100 different subtypes which all behave differently. It’s very important when you have a sarcoma that you see a sarcoma specialist.
Wow. Materially, how does this comprehensive approach yield better outcomes for patients?
Well, just from the surgical perspective, there are many complicated surgeries. If you look at national databases, there's a pretty good correlation between surgeon volume, hospital volume, and short-term outcomes including morbidity and mortality, as well as long-term outcomes including survival. That’s if you just look at national databases and plot the number of cases, complication rates, survival, et cetera. It's important to go to somebody who does a decent volume.
Just understanding the disease will optimize your care. For example, for gastric cancer, there are numerous trials showing that pre- and post-operative chemotherapy improves survival by 10 to 20 percent, your overall survival. And in all those trials, the ability to tolerate chemotherapy for patients before surgery is about 90 percent and after surgery, it's about 50 percent.
If you take out a locally advanced cancer for somebody, you need to do a total gastrectomy on them, and then try to give them chemo afterward. Only half of them are going to be able to finish the chemo afterward because it's much harder to tolerate chemo when you've had your whole stomach removed.
You would think that many of these things are just protocol, or people would just know. But I have frequent interactions with friends, family, and patients, and nonstandard treatment is quite common. If you don't seek out expertise, you may get some sort of deficient care. It's really quite amazing, even for pretty straightforward stuff. It's not like it's really uncommon to go somewhere and get inadequate treatment.
The most important thing is expert level, multi-disciplinary care where everyone's involved: medical oncology, radiation oncology, surgical oncology. For sarcoma, pathology and radiology are very important. We have conferences every week and everyone's there and discussing patient care.
How do research and clinical trials play a role in the understanding of disease, in expert-level care?
For me, in addition to my clinical work, I have a research lab that has between one and three people working in it. It's been NIH-funded since I started. I have an R01 grant that's on its second continuing renewal and we work on things like tumor micro-environment and cancer stem cells. Trying to target these aspects of cancer biology to come up with new treatments. And I've also done some clinical trials of new therapies.
Most significantly in terms of clinical trials is looking at agents that improve the efficacy of the radiation. So, I was the PI [primary investigator] of one clinical trial examining bevacizumab and radiation and then I'm the translational research chair of a cooperative trial that just finished examining pazopanib with radiation or chemoradiation.
That’s part of what I’d like to bring to Columbia. Like Dr. Chabot [chief of GI/Endocrine Surgery] has done with the well-integrated Pancreas Center—you have good clinical care, you have a good multidisciplinary group of people that meet and discuss patients, the lab is doing research, and you are taking lab findings to develop clinical trials—I’m here to expand the Division of Surgical Oncology and to help other divisions expand their research and education activities.
What will be the initial focus of the division of surgical oncology?
I'm first going to focus on gastric cancer, sarcoma, and melanoma. You know, in addition to improving volume, to become a higher-tier surgical oncology center, you really need these other aspects. You need clinical trials, you need clinical research. Ideally, we'd have not just a residency, but also a surgical oncology fellowship or two to provide next level education.
I'm a surgeon, but I learned so much about medical oncology and radiation oncology from my other colleagues. I had clinic with this radiation oncologist at Mass General Hospital named Tom DeLaney. He was a national expert in sarcoma. He basically gave me a mini fellowship on radiation for sarcomas. I actually was the PI of a radiation trial with biologics and he mentored me.
I'm going to try to do have multidisciplinary patient clinics. It's clearly optimal for the patient. It's not great time management for the doctors because it's not as efficient since it's not focused on you, but that isn’t where the focus should be. It's going to be a long effort. My vision is to try to make the surgical oncology care and the cancer care at Columbia to be more comprehensive and diverse.