Oncology Frontier: As the chairman of this CSCO-JSMO/KSMO joint special session focusing on the "Clinical study of High incidence tumors in Asia"， can you talk about some main clinical research developments of your own concern?

 

　　Dr. Bang: For gastric cancer， in the past we have used cytotoxic chemotherapy and targeted agents. Now we have immunotherapy. It has been shown that anti-PD-1 antibodies are effective as third-line treatment for patients with advanced gastric cancer.

 

　　Dr Ohtsu: The progress of immunotherapy is now very rapid. It is a great area for clinical study. In biomarker research for immunotherapy， the anti-PD-1 antibodies achieve a very good response of long duration， but the percentage of responsive cases is still <20%， so this is an area of research that needs to expand.

 

　　Oncology Frontier: In terms of the current status and prospects of immunotherapy in the field of gastric cancer， what are your main views respectively?

 

　　Dr Ohtsu: As I suggested， biomarker research is the most important point for the selection of patients for immunotherapy. Additionally， combination therapy with the anti-PD-1 antibodies will increase the efficacy of therapy for gastric cancer patients.

 

　　Dr Bang: Combinations of anti-PD-1 antibodies and other agents are actively being explored at this time， including with other immune checkpoint inhibitors， targeted agents， or chemotherapy. There are at least three ongoing Phase III   trials at the moment to test the effectiveness of the combination of anti-PD-1 antibody and chemotherapy. The results will be available very soon， and we expect those trial will be positive - resulting in  helping more patients with advanced gastric cancer. Also， anti-PD-1 antibodies are being tested in the adjuvant setting and the neoadjuvant setting， so the scope of immunotherapy in gastric cancer will expand in the future.

 

　　Oncology Frontier: At present， there is still a lot of controversy about perioperative treatment of gastric cancer. Could you give us a brief account of main progress in this area?

 

　　Dr Bang: I should mention the differences in surgical techniques between Asian countries and Western countries. In Asia， we believe our surgical techniques are very good， and we use post-operative chemotherapy to improve the cure rate. However， in the West， surgical techniques are less good and a perioperative approach is effective， so this  approach is preferred in the Western countries. As I have mentioned， immunotherapy is also being tested in these settings.

 

　　Dr Ohtsu: In Japan， a recent topic of interest is the combination of S-1 (tegafur， gimeracil， and oteracil) with docetaxel， which achieves a significant improvement in post-operative adjuvant settings. That will be standard treatment for stage 2/3 gastric cancer in Japan， and a great advance. Of course， we are also participating in the adjuvant trials with anti-PD-1 antibodies， as Professor Bang mentioned. We hope this leads to an improvement in the cure rate for gastric cancer patients.

 

　　Oncology Frontier: We know that the cancer gene screening project for digestive tract tumors has been launched in Japan. What do you think is the significance to the clinical diagnosis and treatment of gastrointestinal tumors?

 

　　Dr Ohtsu: We launched the nationwide gene screening project， SCRUM-Japan， three years ago. We have enrolled approximately 10000 patients for lung and GI cancers. Genetic profiling is well underway for the GI cancers， including gastroesophageal cancers. There are driver genes， particularly in gastric cancer， that are being focused on in studies such as EGFR and c-MET， and there are some very rare cases with ROS1 and ALK， as have been seen with lung cancer. So we have data for only a tiny fraction of all the driver genes， but these patients achieve good responses to the relevant targeted agents， but these populations are very small and we need to have more efficacious agents for gastric cancer. There are many driver genes in colorectal cancer and in the joint session here at CSCO， there will be discussions about several clinical trials underway looking at targeted agents for colorectal cancer.

 

　　Dr Bang: We started a similar nationwide program in Korea last year.We  need more time to accumulate more data.