Published online Aug 21, 2020. doi: 10.3748/wjg.v26.i31.4718
Peer-review started: January 20, 2020
First decision: February 27, 2020
Revised: May 15, 2020
Accepted: August 1, 2020
Article in press: August 1, 2020
Published online: August 21, 2020
Processing time: 213 Days and 19.7 Hours
Congenital intrahepatic bile duct dilatation without fibrosis is called Caroli disease (CD), and is called Caroli syndrome (CS) when it has fibrotic and cirrhotic liver morphology. The development of intrahepatic carcinoma is described in both conditions, but the reported incidence varies extensively. Furthermore, there are no valid guidelines how to treat and diagnose malignant transformation in these patients.
So far no valid potential risk factors for the malignant transformation were described. Furthermore, conservative or surgical treatment is performed depending on the extent of cystic malformation, hepatic dysfunction and structural hepatic changes, but little is known about which treatment should be offered to patients with CD or CS and especially cancer.
We performed a systematic review of the current literature to investigate specific conditions for malignant transformation in patients with CD and CS and to identify potential risk factors and recommendations regarding diagnosis and surgical treatment.
A systematic review of the current literature until January 2019 was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. During screening process, non-English articles and reports with less than five patients were excluded. The search was performed using a combination of Medical Subject Headings terms “caroli disease”, “caroli syndrome”, “tumor”, “malignant”, and “cholangiocarcinoma”. Only human studies were used for this systematic review.
Twelve retrospective studies reporting the courses of 561 patients (53% females) were included in this systematic review. The patients’ mean age was 41.6 years old (range 23 to 56 years old), therefore patients were younger than other populations undergoing liver surgery. The incidence of cholangiocarcinoma varied from 2.7% to 37.5% with an overall incidence of 6.6%. There were only few detailed reports about preoperative diagnostic work-up. Disease duration was variable with up to several years. In most cases tumor detection was an incidental finding of the surgical specimen as tumor detection in preoperative diagnostics was often impossible. Surgical treatment depended on the extent of the biliary pathology and additional alterations of the liver structure or function. No adjuvant chemotherapy was reported. Overall survival rates after one year were low at 36% and a high recurrence rate of up to 75% during the observation period was seen.
Only few retrospective studies are available and reported a low tumor incidence. On the basis of these studies distinct suggestions regarding diagnosis and treatment are impossible to define. Despite the high rate of mortality and tumor recurrence, definite surgical treatment should be offered as soon as possible.
Further prospective multicenter investigations regarding patient surveillance, diagnostic tools, time point of surgery and risk factors of malignant transformation are needed.