"Although I'm a surgeon, my greatest interest lies in oncology. My goal is to develop more effective treatments for terminal patients with metastatic gastric cancer, for whom surgery is not feasible."
On the 7th, at Seoul National University Bundang Hospital in Seongnam, Gyeonggi Province, we met Professor Kang So-hyun (34) of the Division of Gastrointestinal Surgery. Now in her sixth year as a surgeon, Kang is a seasoned operator with a scalpel, but her work does not stop at simply removing tumors. She is a physician who conducts research to discover better treatment options for patients who cannot undergo surgery.
Professor Kang has focused on patients with metastatic advanced gastric cancer. When detected early, gastric cancer has a more than 90% chance of being cured, but if it spreads to other organs, the prognosis deteriorates sharply. Gastric cancer often spreads to the peritoneum, which is the thin membrane that lines the abdominal cavity, or to the liver. Particularly, the median survival time for stage 4 metastatic cancer patients is less than 1 year.
Currently, various methods are being attempted for patients with peritoneal metastasis, including cytoreductive surgery (CRS) to partially remove metastatic cancer, radiation therapy, and systemic chemotherapy using cytotoxic anticancer drugs; however, there is still no treatment that dramatically improves survival rates. The efficacy of immune anticancer drugs that induce the immune system to attack only cancer cells is also limited.
Professor Kang explained, "The chemotherapy injected intravenously does not reach the peritoneum sufficiently, which reduces its effectiveness," adding, "The blood vessels in the peritoneum have less blood flow than other organs, making the drug pathway narrow, and the peritoneal-plasma barrier between the peritoneum and blood hinders drug penetration."
An alternative that has emerged is 'intraperitoneal chemotherapy.' Professor Kang said, "Since vascular injection is insufficient, we inject the chemotherapy directly into the abdomen," noting that "there is an advantage in delivering the anticancer drugs at a high concentration to the peritoneum."
This treatment method has been known since the 1970s, but it has not shown significant results in gastric cancer yet. A large-scale phase 3 clinical trial conducted in Japan in 2019 also did not yield notable improvements in survival rates. However, subsequent follow-up observations indicated a slight increase in survival rates, suggesting that there remains potential.
Leading Professor Kang in this research was Kim Hyung-ho, a former gastrointestinal surgery professor at Bundang Seoul National University Hospital (now at Chungang University Gwangmyeong Hospital), an authority on gastric cancer surgeries in Korea. Having participated in the phase 1 and 2 clinical trials led by him in 2019, Professor Kang became fascinated with research that combines surgical procedures and chemotherapy.
In the phase 2 trial, world-class results were achieved. Patients who received combination therapy with paclitaxel and a cytotoxic anticancer drug (FOLFOX) injected into the abdomen showed a median survival time of 20.2 months. The progression-free survival (PFS), which is the period during which the disease does not worsen after treatment, was 13.1 months, twice as long as the 7.46 months for immunotherapy. For this achievement, Professor Kang received the 'Best Researcher Award' at the Korean Surgical Society's fall conference in November last year.
Now she has taken over from her mentor as the principal investigator (PI) and is leading the final phase 3 trial of this research. This time, 321 patients with terminal gastric cancer that has metastasized to the peritoneum will be targeted, comparing the survival rates of patients who received FOLFOX monotherapy with those who received paclitaxel and FOLFOX together injected into the abdomen. Six hospitals nationwide, including Seoul National University Hospital, Samsung Medical Center, Asan Medical Center, and Yonsei University Severance Hospital, will participate.
Professor Kang's team does not stop merely at verifying drug efficacy. The ultimate goal is to establish an optimal treatment system for patients with advanced gastric cancer through a multidisciplinary approach that combines surgery, chemotherapy, AI (artificial intelligence)-based imaging and pathology diagnosis, and organoid research. Organoids are mini-organs created by differentiating stem cells into specific organ cells and cultivating them in three dimensions. They can test the effects of drugs or treatments instead of actual organs.
Professor Kang said, "We plan to develop imaging and AI diagnostic technologies in collaboration with the Department of Radiology and establish an organoid model that mimics peritoneal metastatic cancer with the Department of Basic Medical Sciences, and to conduct cell analysis studies with the Department of Pathology to create an overall treatment system," adding, "We also plan to collaborate with the Department of Hematology and the area of immunotherapy." This means the entire hospital is mobilized to overcome terminal metastatic cancer.
Professor Kang graduated from Seoul National University College of Medicine and joined Bundang Seoul National University Hospital as a gastrointestinal surgery professor in 2020. She is currently also serving as a commissioner for the Medical Artificial Intelligence Center at Bundang Seoul National University Hospital. She said, "Chemotherapy is mainly in the field of internal medicine, but as a surgeon, I want to find a unique role in delivering anticancer drugs through other pathways," emphasizing, "My dream is to develop new treatments that combine surgery and oncology for patients who are difficult to operate on."