Compared with other cancers that are generally considered cured if there is no recurrence for 5 years after treatment, ‘extrahepatic bile duct cancer’ still carries a high risk of recurrence even 5 years after surgery, so continued management is needed, according to a study. The researchers noted, however, that survival improves with time from immediately after surgery, offering hope for treatment.

On the 6th, a research team led by Professor Kim Hong-Beom of the Department of Hepatobiliary and Pancreatic Surgery; Professors Shin Dong-Wook and Choi Hye-Rim of the Department of Family Medicine; and Professor Kang Dan-Bi of the Clinical Epidemiology Research Center at Samsung Seoul Hospital announced an analysis of conditional survival to accurately assess the long-term prognosis of patients with extrahepatic bile duct cancer. The study was published in Hepato-Pancreato-Biliary, the official journal of the International Hepato-Pancreato-Biliary Association.

Extrahepatic bile duct cancer is a malignancy that occurs in the bile ducts that connect outside the liver among the ducts through which bile produced in the liver flows. It is known as a representative intractable cancer because the risk of recurrence remains high even after surgery. To calculate the real-world survival prospects of patients who underwent surgery for this disease, the researchers analyzed conditional survival, which recalculates the future likelihood of survival given survival for a certain period, instead of using a fixed survival rate.

The analysis showed that, compared with a 5-year survival rate of 41.3% at the time immediately after surgery, the subsequent 5-year survival rate for patients who had already survived 5 years after surgery rose to 51.9%. The probability of remaining free from recurrence also increased from 29.3% at the time of surgery to 50.0% at the 5-year mark after surgery. Notably, even among stage III patients, who have a poorer prognosis, survival prospects improved markedly over time, with the survival rate rising from 14.6% immediately after surgery to 53.3% 5 years later.

The researchers explained that, although extrahepatic bile duct cancer showed a pattern in which long-term survival prospects gradually increased if patients did well for a certain period, in contrast to the relatively unfavorable outlook early in treatment, there are also clear points of caution. Even if there is no recurrence during the first 5 years after surgery, about a 40% level of recurrence risk remains thereafter, and after 6 years the risk does not decline substantially. This likely reflects invisible micrometastasis or the biological characteristics of the cancer, meaning the possibility of recurrence does not completely disappear even for long-term survivors.

Professor Choi Hye-Rim said, “This study is the first to comprehensively analyze time-dependent changes in survival in extrahepatic bile duct cancer,” adding, “It provides grounds for patients to have realistic hope during treatment.” Professor Kim Hong-Beom stated, “Although the risk of recurrence decreases over time in extrahepatic bile duct cancer, it does not disappear completely,” and added, “Regular checkups and long-term health management are essential even after 5 years.”