Cholangiocarcinoma: Expanding the Spectrum of Risk Factors

Frequency and prognostic significance of isocitrate dehydrogenase 1 mutations in cholangiocarcinoma: a systematic literature review

BACKGROUND

The recognition of distinct molecular subgroups within cholangiocarcinoma (CC), along with the increasing availability of targeted therapies, suggests that further characterization of the prevalence and prognosis of frequently occurring subgroups may assist with the development of more effective treatment approaches for the management of CC. A systematic review was performed to investigate the prevalence of isocitrate dehydrogenase 1 (IDH1) mutations (mIDH1) in patients with CC, the possible clinical and prognostic significance of mIDH1, and the presence of co-mutations in tumors with mIDH1.

METHODS

This review was conducted using the Cochrane dual-reviewer methodology and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol (PRISMA-P) guidelines. Searches were performed in Embase, MEDLINE, the Cochrane Central Trials Register and Database of Systematic Reviews, and other Cochrane Library assets using terms for CC and mIDH1 with no language or date restrictions for articles published up to December 31, 2017. Searches were also performed of abstracts presented at the following conferences in 2016 and 2017: American Society of Clinical Oncology (ASCO), ASCO-Gastrointestinal Cancers Symposium (ASCO-GI), the European Society for Medical Oncology (ESMO), and ESMO-Asia. Screening was performed separately by two reviewers and cross-checked. Any discrepancies between reviewers were resolved by a senior researcher. Data from all selected references were recorded in a data extraction grid.

RESULTS

A total of 46 publications met the inclusion criteria and were included in the systematic review. Of these publications, 45 reported the frequency of mIDH1 among a total sample of 5,393 patients with CC. mIDH1 was enriched in intrahepatic CC (ICC), with 552 (13.1%; 95% CI, 12.1-14.2) of the 4,214 patients with ICC having the mutation compared with 9 (0.8%; 95% CI, 0.4-1.5%) of the 1,123 patients with extrahepatic CC (ECC). The percentage of females with mIDH1 CC (66.2%; 95% CI, 57.7-73.7%) was higher than in the overall CC population (44.4%). The frequency of mIDH1 in patients with ICC reported in individual studies ranged from 4.5-55.6%, and a significantly higher frequency was reported in non-Asian centers compared with Asian centers (weighted mean, 16.5% vs. 8.8%; P<0.001). The prevalence of mIDH1 in patients with ICC at USA centers was 18.0% (95% CI, 16.4-19.8%). Eleven publications reported the prevalence of co-mutations in patients with mIDH1 ICC, with the most frequent being AT-rich interactive domain-containing protein 1A (ARID1A) (22.0%), BRCA1-associated protein 1 (BAP1) (15.5%), and PBRM1 (13.3%). Eight publications investigated the possible prognostic significance of mIDH1. None of the studies reported a statistically significant association between mIDH1 and overall survival (OS), progression-free survival (PFS), or time to progression.

CONCLUSIONS

This systematic review substantiates the prevalence of mIDH1 in CC and further characterizes clinical, pathologic, and genetic covariates within this sub-population. Co-mutation data may inform future studies of mechanisms of response and resistance to mIDH1-targeted therapies.

Autoimmune Hepatitis: A Risk Factor for Cholangiocarcinoma

Cholangiocarcinoma (CCA) is a very aggressive and lethal tumor, which arises from the epithelial cells of bile ducts. CCA comprises about 3% of all gastrointestinal malignancies and its incidence is on the rise in the recent years. Anatomically, it is classified into intrahepatic, perihilar, or extrahepatic (distal) CCA. There are a number of risk factors associated with CCA including primary sclerosing cholangitis, fibropolycystic liver disease, parasitic infection, viral hepatitis, chronic liver disease, and genetic disorders like Lynch syndrome. Autoimmune hepatitis is also recently reported to have an association with development of CCA. We report an interesting case of perihilar CCA in the setting of autoimmune hepatitis along with a literature review. This case highlights the importance of early treatment and close clinical follow-up of patients with autoimmune hepatitis for development of CCA.

Surveillance in cholangiocellular carcinoma

Cholangiocellular carcinoma is the most frequent malignant neoplasm originating from the epithelium of intra- or extrahepatic bile ducts. In the past decades, the incidence of cholangiocarcinoma has been shown to increase while overall mortality has remained high with an approximate 5-year overall survival below 20%. Surgery remains the only curative option while systemic treatment is limited to palliative chemotherapy. Therefore, surveillance strategies for patients at risk of developing cholangiocarcinoma are urgently needed, particularly in patients with primary sclerosing cholangitis and patients infected with liver flukes. Here we summarize the currently available data on surveillance of risk populations and methods for the detection of cholangiocarcinoma.

Long-term outcome of Japanese patients with type 1 autoimmune hepatitis

The long-term outcome of patients with autoimmune hepatitis (AIH) in Japan has not been well-defined. The aim of this study was to clarify the outcome of this disease over a long follow-up period compared with that of the general Japanese population as well as that among patients. A total of 203 AIH patients were enrolled for a mean follow-up period of 131 months. All patients were treated with corticosteroids with or without azathioprine. The overall survival of AIH patients was similar to that of the general population in Japan. The prognosis of AIH subgroups divided according to disease severity, sex, incidence of relapse, liver histology, presence of cirrhosis, probable or definite AIH score, antibody to hepatitis B core antigen antibody positivity, or human leukocyte antigen DR4-positivity did not differ greatly among patients. However, the prognosis of patients experiencing two or more relapses was significantly poorer than that of patients with remission or a single relapse both in univariate (P < 0.001) and multivariate (P = 0.020) analyses. The development of liver malignancy was also a possibility among AIH patients with multiple relapses. Severe adverse effects of corticosteroids were rare, even in patients who underwent long-term treatment.

CONCLUSION

Repeated relapses of AIH are significantly associated with a poorer long-term prognosis in Japan. AIH patients can expect a similar prognosis to that of the general population, provided they are adequately managed with continuous low doses of immunosuppressive therapy, especially after the first relapse.

Endoscopic ultrasound with biopsy of omental mass for cholangiocarcinoma diagnosis in cirrhosis

In this report, a patient had a previous diagnosis of cholangiocarcinoma with an extended cholecystectomy. Three years later, he was evaluated for recurrent ascites. The patient had several large volume paracentesis, without evidence of malignant cells. Subsequently, endoscopic ultrasound (EUS) with fine needle aspiration (FNA) of both lymph and omental nodules was utilized. While the lymph nodes were negative for malignancy, the omental nodule was interrogated with multiple antibodies and was found to be positive for neoplasia. EUS with FNA can safely be used in patients with cirrhosis to spare the patient invasive evaluation such as exploratory laparotomy (ex-lap) for diagnosis and staging of cholangiocarcinoma.

Use of endoscopic ultrasound for diagnosis of cholangiocarcinoma in auto-immune hepatitis

In this report, a patient was exposed to an herbal remedy for hypercholesterolemia. She became acutely jaundiced while taking the remedy and presented for medical care. Endoscopic ultrasound was utilized, and found a distal common bile duct mass. Endoscopic retrograde cholangiopancreatography guided bile duct biopsies revealed that the mass was cholangiocarcinoma (CCA). This case highlights a unique association between autoimmune hepatitis and CCA. It also highlights that EUS can be safely used in patients with cirrhosis to spare invasive evaluation such as exploratory laporotomy for diagnosis and staging of cholangiocarcinoma.

Agrin immunohistochemistry facilitates the determination of primary versus metastatic origin of liver carcinomas

In our earlier work, we demonstrated that agrin, a multifunctional heparan sulfate proteoglycan, accumulates in hepatocellular carcinoma (HCC) and cholangiocellular carcinoma (CCC). In addition, we proved the utility of agrin immumohistochemistry in discriminating between HCCs and benign parenchymal lesions. Here, we have examined the expression of agrin in metastatic liver carcinomas in comparison with primary liver tumors. Immunohistochemistry for agrin was performed on 25 HCC, 16 intrahepatic CCC, 20 colorectal cancer metastasis (CRCm), and 18 pancreatic ductal carcinoma metastasis (PDCm) samples and evaluated with both quantitative and qualitative methods. Agrin/CD34 double immunofluorescent staining was carried out on snap-frozen sections. Agrin mRNA expression was measured in 11 HCC, 7 CCC, 11 CRCm, and 12 normal liver tissues. Regardless of tumor grade, agrin immunostaining was strong in the microvessels of HCCs. As opposed to HCC, agrin immunostaining was faint or nearly absent from the CD34-positive microvessels of CCC, CRCm, and PDCm; rather, it was detected in the basement membranes surrounding tumor cell pseudoglandules. While agrin was preserved in the basement membranes of Grade III CCCs, it was nearly absent from poorly differentiated metastatic adenocarcinomas. Agrin mRNA levels were the highest in CCC and lower, but still elevated in HCC and CRCm. By qualitative evaluation of agrin immunoreactions, CCC was differentiated from CRCm and PDCm with a sensitivity of 0.81 and a specificity of 0.82. HCCs were unequivocally identified on the basis of microvascular agrin labeling. Thus, agrin immunohistochemistry may facilitate determination of primary versus metastatic origin in problematic liver cancer cases.