Johanna Bendell, MD: Hello, and welcome to this OncLive Peer Exchange® titled, “Updates for Treatment of Advanced Gastric and Gastro-Esophageal Cancers.”
I am Dr Johanna Bendell from the Sarah Cannon Research Institute in Nashville, Tennessee.
Joining me today in this discussion are my colleagues, Dr Daniel Catenacci from the University of Chicago, Dr Ian Chau from the Royal Marsden Hospital in London, Dr Yelena Janjigian from Memorial Sloan Kettering Cancer Center in New York, and Dr Ken Kato from the National Cancer Center Hospital in Tokyo, Japan.
Today we are going to discuss a number of topics pertaining to the use of systemic therapy for gastric and gastroesophageal malignancy. We will discuss the latest research in the field including some very exciting abstracts that are being presented during the Presidential Session at the European Society for Medical Oncology 2020 Virtual meeting and their impact on clinical practice.
Let’s get started on our first topic.
Let’s set the stage for how we approach gastroesophageal cancers in our practice. We know that there are different trends in epidemiology, and histology, like how patients are treated in western countries versus eastern countries. Ian, can you give us some background on incidence, prognosis of gastroesophageal cancers, and how this might differ worldwide?
Ian Chau, MD: Yes. Certainly, there are geographical variations in terms of gastric and esophageal cancers. I think perhaps it is important to look at it according to histology. We normally think about it as adenocarcinoma or squamous cell cancer. For adenocarcinoma, in the Western world certainly the incident of gastric adenocarcinoma has been declining. Instead the adenocarcinoma from the junction of the esophageal gastric junction has been increasing, and that has been due to several potential risk factors in the western world, mainly to do with the reflux disease, the body weights, obesity, and incidence of obesity in the western world. That all leads to a rise in adenocarcinoma of the esophageal gastric junction.
Now for squamous cell cancer the incidence is generally much lower in the western world compared with East Asia. I’m sure my colleague, Ken, will talk about that a lot. The vast majority of squamous cell cancer does happen in China, Japan, Korea, and also in some parts of Africa, but it is still a very important disease in the Western world where it is more related to some of the environmental factors as smoking, drinking, and perhaps with the use of very hot tea. Certainly there is geographical variations in terms of these diseases.
Prognosis is still poor generally. I mean we are hoping to diagnose patients who are still at a stage that radical treatment can be used. For example, in the UK for gastric cancer, only about 30% to 35% of gastric cancer are diagnosed in a stage where radical surgery and therefore perioperative or preoperative strategy can be used. Another 20% to 30% are probably locally advanced. Still, sadly, most patients are still diagnosed in a metastatic disease setting. That’s still a very real, high unmet needs in the Western world. Although no gastric cancer is diagnosed in the early stage in East Asia.
Similarly, for squamous cell cancer of the esophagus, I would say that the majority of our patients are still diagnosed in a stage which are beyond radical treatment, whether the radical treatment is chemoradiation or chemoradiation followed by surgery. I think all in all, although there is a geographical variation, the prognosis of this disease still remains poor, and I think there is still a high level unmet needs throughout the world.
Johanna Bendell, MD: Ken, being from Tokyo, how did you approach gastric, gastroesophageal cancers, and cancers of the esophagus in Japan with that higher incidence rate?
Ken Kato, MD, PhD: In Japan the proportion of gastric cancer is higher than the Western countries because we have a medical checking-up system for gastric cancer around the country. More than half of the patients are diagnosed at an earlier stage, and 20% to 30% of the patients received endoscopic treatment therapies.
Due to the COVID-19 coronavirus disease 2019 pandemic, the medical checking-up system has stopped for months. The recent number of patients with earlier upper gastrointestinal cancer has decreased, so I wonder if these patients will come to our hospital with more advanced cases.
Johanna Bendell, MD: And what is the difference in risk factors that you’re seeing in Japan versus what we see in the United States—Ian was talking about obesity and reflux disease. For Japan, certainly different epidemiology results potentially in a different histology.
Ken Kato, MD, PhD: Yes. Of course, in Japan, so obesity is not common, but the Helicobacter pylori infection influences the incident of gastric cancer. Recently, however, the Helicobacter pylori incidence was lower along with the gastric cancer that has been continuing to decrease recently.
Transcript Edited for Clarity