South Korea Ranks 2nd in Global Incidence... Silent Onset of Bile Duct Cancer [Kok! Health]

South Korea is one of the leading countries in cancer treatment worldwide. Along with continuously advancing medical technology, various policies such as health insurance support have significantly increased the survival rates of major cancer types. In particular, the 5-year survival rate of stomach cancer, which was around 43.9% in the 1990s, has recently risen to 77.9%, showing a significant improvement in the survival rates of gastrointestinal cancers.

However, there is still a type of cancer for which South Korea ranks second in patient incidence worldwide and first in mortality worldwide. This is cholangiocarcinoma. The bile duct is the pathway through which bile, which digests fats, flows. Bile is produced in the liver and secreted into the small intestine through the bile duct to perform its function. The gallbladder, where the produced bile is temporarily stored, is called 'sulgae' in Korean. Cancer that occurs in the bile duct and gallbladder is called cholangiocarcinoma. The 5-year survival rate for cholangiocarcinoma is only about 30%.

The causes of cholangiocarcinoma are still not well understood. It is only presumed that conditions such as cholelithiasis, ulcerative colitis, congenital hepatic fibrosis, and chronic typhoid carriers are related to the occurrence of cholangiocarcinoma. In terms of symptoms, the main ones include discomfort in the upper abdomen and back, indigestion, and loss of appetite, which are common symptoms in other diseases as well, making it difficult to determine the presence of cholangiocarcinoma based on these symptoms alone, thus making early detection challenging. Moreover, these symptoms often appear only after the cancer has significantly progressed. However, another representative symptom is jaundice, which occurs when the bile duct is blocked, causing the skin and the whites of the eyes to turn yellow, and in such cases, early detection can sometimes be fortunate.

Additionally, in terms of actual diagnosis, the bile duct is located deep inside the body, spanning the liver and duodenum, and its shape spreads like branches within the liver, while outside the liver it is about the thickness of a straw, making early detection difficult with ultrasound or endoscopy.

As a result, 7 out of 10 cholangiocarcinoma patients are diagnosed at a stage where surgery is no longer possible. Even if surgery is possible, it is known that 60-70% of patients experience cancer recurrence. Furthermore, unlike other cancers where new treatments are continuously emerging, there has been no drug available for patients with unresectable locally advanced or metastatic cholangiocarcinoma, resulting in low survival rates.

Consequently, the only treatment option available for these patients was combination chemotherapy, with an expected survival of only about one year. Also, since cholangiocarcinoma often occurs in elderly patients over their 60s, many face difficulties in treatment due to the burden of side effects. However, recently, treatment conditions have been improving with the introduction of combination therapy using the immuno-oncology drug durvalumab and chemotherapy.

Immuno-oncology drugs strengthen the immune system to eliminate cancer cells and have the advantage of fewer side effects and sustained anticancer effects compared to conventional chemotherapy. In clinical trials led by domestic medical staff, including Professor O Do-yeon of the Hematology-Oncology Department at Seoul National University Hospital, the combination therapy showed a 2.12-fold increase in survival probability at the 3-year treatment mark compared to existing therapies. The National Comprehensive Cancer Network (NCCN), an international standard guideline for cancer treatment, also recommends immuno-oncology combination therapy as the first-line treatment.

However, this therapy is not yet fully covered by health insurance in South Korea. At the beginning of the year, insurance coverage began for chemotherapy in this combination therapy with immuno-oncology drugs, but the immuno-oncology drugs themselves, which are the core of the treatment, remain non-reimbursed. This has led to criticism that South Korea’s response is delayed compared to overseas cases such as the United States and the United Kingdom, which have promptly approved insurance coverage for immuno-oncology drugs to improve the limited treatment environment for cholangiocarcinoma.