Expert panelists open their discussion on biliary tract cancers by identifying various subsets and noting the growing incidence of these diseases.
Milind M. Javle, MD: Hello and welcome to this OncLive® Peer Exchange, entitled “Diagnosis and Treatment of Biliary Tract Cancers.” I am Milind Javle. I’m a medical oncologist at the University of Texas MD Anderson Cancer Center in Houston. Joining me today are my colleagues in biliary tract cancer, they are experts in the field. Dr Eugene Koay.
Eugene J. Koay, MD, PhD: Hi, everybody. I’m a radiation oncologist at MD Anderson.
Milind M. Javle, MD: Dr Rachna Shroff.
Rachna Shroff, MD: Hi, everyone. I’m a GI [gastrointestinal] medical oncologist at the University of Arizona Cancer Center in Tucson.
Milind M. Javle, MD: Dr Flavio G. Rocha.
Flavio G. Rocha, MD, FACS, FSSO: Hello. I’m a surgical oncologist and hepatobiliary surgeon at Oregon Health & Science University in Portland.
Milind M. Javle, MD: Welcome again, and thank you for joining us. Let’s get started on our first topic.
I’m going to first talk in general terms about the incidence of biliary tract cancer and factors that put patients at high risk of developing that cancer. Dr Rocha, I know this is an area of controversy. Is it well established what the incidence of biliary tract cancer is? Before going there, could you educate us on the types of biliary tract cancer incidence in the various parts of the world?
Flavio G. Rocha, MD, FACS, FSSO: Thank you, Dr Javle. This is an area of active investigation, partly because these tumors are considered to be rare. In fact, the American Cancer Society just put out their estimates for 2023. They’ve estimated that we’ll have an incidence of about 40,000 liver and intrahepatic bile duct cancers in the next year. That number is a little deceiving because it will include hepatocellular carcinoma as well. When you look at gallbladder cancer then and other biliary tract cancers, we’re looking at about 12,000 cases coming in 2023.
Keep in mind, these are 4 separate diseases. Think of the bile ducts that start in the liver, the intrahepatic bile ducts and intrahepatic cholangiocarcinoma. Then as you move down, you get to the extrahepatic cholangiocarcinoma, which is then broken down into 2 separate diseases. There are the hilar tumors or perihilar, formerly known as Klatskin tumors, as well as the distal cholangiocarcinomas, which are at the end of the bile duct located in the head of the pancreas. Then lastly, there’s gallbladder cancer, which as we know is an outpouching of the bile duct. They’re really 4 separate diseases.
Milind M. Javle, MD: Why do people get these cancers? What do you think are the risk factors, Dr Rocha?
Flavio G. Rocha, MD, FACS, FSSO: There are some identified risk factors, but for the majority of patients we see we don’t really have an etiology. Of course, there are regional differences, whether the patients are diagnosed in the West or in the East of the world. In Asia for example, these cancers are more prevalent, we think perhaps due to either parasitic infections or diet changes. In the West, we obviously have other risk factors, such as metabolic syndrome. For any disease that also causes inflammation, for example folks who have chronically inflamed gallbladders may develop gallbladder cancer. There are obviously some familial syndromes, which I’m sure we’ll get into later in the talk. Those are the only real established risk factors.
Milind M. Javle, MD: Dr Shroff, I realize we’re all working in referral centers, but we are all seeing a lot of patients, and it seems to me like the incidence may be even higher than what Dr Rocha estimated. Do you get that impression? If so, what could be the possible explanation of that?
Rachna Shroff, MD: I absolutely agree. I think we are probably underestimating the incidence, and there are a number of reasons for that. I do also think we’re seeing an increasing in incidence. There are the various risk factors that were mentioned, our lifestyles and underlying fatty liver disease. The rise of those types of things are increasing the risk for developing, for instance, intrahepatic cholangiocarcinomas. But we also know that carcinomas of unknown primary, which have been historically hard to classify. We know as we’ve gotten better with biomarker testing, molecular profiling, and radiographic imaging, we’re doing a better job of taking what were traditionally carcinomas of unknown primary and recognizing them as cholangiocarcinomas. I think there are a lot of different things that are weighing into it, not to mention some of the basic factors, like the fact that liver and intrahepatic bile ducts are all lumped together.
Milind M. Javle, MD: Sure. Let’s hope we have some strategies to decrease this unfortunate rising incidence of this cancer. We’ll get there a little later.
Transcript edited for clarity.