Meta-analysis of risk of developing malignancy in congenital choledochal malformation

Abstract

Background: Choledochal malformations comprise various congenital cystic dilatations of the extrahepatic and/or intrahepatic biliary tree. Choledochal malformation is generally considered a premalignant condition, but reliable data on the risk of malignancy and optimal surgical treatment are lacking. The objective of this systematic review was to assess the prevalence of malignancy in patients with choledochal malformation and to differentiate between subtypes. In addition, the risk of malignancy following cystic drainage versus complete cyst excision was assessed.

Methods: A systematic review of PubMed and Embase databases was performed in accordance with the PRISMA statement. A meta-analysis of the risk of malignancy following cystic drainage versus complete cyst excision was undertaken in line with MOOSE guidelines. Prevalence of malignancy was defined as the rate of biliary cancer before resection, and malignant transformation as new-onset biliary cancer after surgery.

Results: Eighteen observational studies were included, reporting a total of 2904 patients with a median age of 36 years. Of these, 312 in total developed a malignancy (10·7 per cent); the prevalence of malignancy was 7·3 per cent and the rate of malignant transformation was 3·4 per cent. Patients with types I and IV choledochal malformation had an increased risk of malignancy (P = 0·016). Patients who underwent cystic drainage had an increased risk of developing biliary malignancy compared with those who had complete cyst excision, with an odds ratio of 3·97 (95 per cent c.i. 2·40 to 6·55).

Conclusion: The risk of developing malignancy among patients with choledochal malformation was almost 11 per cent. The malignancy risk following cystic drainage surgery was four times higher than that after complete cyst excision. Complete surgical resection is recommended in patients with choledochal malformation.

Figure 1

Todani classification of choledochal malformations5

Figure 2

Flow chart showing selection of articles for review. NOS, Newcastle–Ottawa Scale

Figure 3

Age at development of malignancy in relation to prevalence of malignancy, and development of malignant transformation after drainage and after hepaticojejunostomy. Data from six studies7, 22, 26, 32, 34, 38 comprising 58 patients

Figure 4

Median age of patients with choledochal malformation at presentation of malignancy in each study. The size of each blue circle indicates the study sample size, and that of each red circle the incidence of choledochal malformation, relative to that in the other studies

Figure 5

Forest plot comparing development of malignancy in patients treated with drainage procedures and compared with those who underwent complete cyst excision followed by a Roux‐en‐Y hepaticojejunostomy. A Mantel–Haenszel fixed‐effect model was used for meta‐analysis. Odds ratios are shown with 95 per cent confidence intervals