Survival after Surgery among Cholangiocarcinoma Patients Comparing between Mucin Producing and Non-Mucin Producing.

Background: Mucin-producing cholangiocarcinoma (MPCC) was rare biliary tract malignancy. Studies regarding this type of cholangiocarcinoma (CCA) were limited, particularly the survival outcome. We aim to evaluate the survival rate, median survival time after surgery among CCA patients and to determine the association between MPCC and survival.

Objective: To evaluate survival rate, median survival time after surgery among cholangiocarcinoma patients and to determine the association between mucin-producing cholangiocarcinoma and survival.

Methods: CCA patients who underwent surgery between 2013 and 2020 from the Cholangiocarcinoma Screening and Care Program (CASCAP), Northeast Thailand were included in the study. The MPCC was based on pathological findings after surgery. The survival of CCA patients was verified through medical records and civil registration. Survival rates and median survival time since the date of CCA surgery and its 95% confidence intervals (CI) were estimated. Multiple cox regression was performed to evaluate factors associated with survival which were quantified by adjusted hazard ratios (AHR) and their 95% CI.

Results: Of 1,249 CCA patients which constituted 24,593 person-months, 687 died at the completion of the study. The overall incidence rate was 2.79 per 100 patients per month, the median survival time was 21.77 months (95% CI: 19.87 - 23.84), and the 5-year survival rate was 28.29% (95% CI: 24.99 - 31.67). From these patients, 210 (16.81%) were MPCC, the incidence rate was 1.81 per 100 patients per month, median survival time was 41.21 months (95% CI: 26.16 - 81.97), and 5-year survival rate was 44.69% (95% CI: 32.47 - 56.16). MPCC were 35% less likely to died compared with non-MPCC (AHR = 0.65; 95% CI: 0.50 - 0.84).

Conclusions: Our study revealed that CCA patients with MPCC had longer survival times and higher survival rates than those without MPCC. This classification will lead to appropriate treatment guidelines for CCA patients.