Molecular targeted therapy for biliary tract malignancy: defining the target

Differential Diagnosis of Immunoglobulin G4-associated Cholangitis From Cholangiocarcinoma

BACKGROUND AND AIM

Immunoglobulin G4-associated cholangitis (IAC) shares many similar symptoms with cholangiocarcinoma (CCA). However, the treatment and the prognosis are substantially different. This study aimed to identify the important markers for the differential diagnosis of these 2 diseases.

METHODS

Thirty IAC patients and 275 CCA patients were reviewed retrospectively for their clinical symptoms, serological tests, and imaging characteristics. Posttreatment responses were also studied.

RESULTS

IgG4 had 100% specificity for IAC at a cutoff of 6 times the upper normal limit. IAC patients had a significantly higher incidence of weight loss (P=0.025) and a higher level of weight loss (P=0.008) than CCA patients. The positive rates of biological markers CA199, CA242, and CEA in CCA and IAC were 81.5% versus 42.9%, 45.5% versus 4.5%, and 29.2% versus 7.1%, respectively. Levels of these tumor markers in CCA were significantly higher than in IAC (P<0.05). The thickened wall [17/18 (94.4%) vs. 3/10 (30%), P=0.001] and the occupying lesion on the bile duct [1/18 (5.6%) vs. 8/10 (80%), P<0.001] were found to be significantly different in IAC and CCA, respectively, by endoscopic ultrasonography. Autoimmune pancreatitis was the most frequently observed comorbidity of IAC (25/30). All IAC patients respond positively to steroid treatment.

CONCLUSIONS

Increased tumor markers, 6-fold higher levels of serum IgG4, and other organs' involvement could be the reference factors for a differential diagnosis of IAC and CCA. Endoscopic ultrasonography might be an effective imaging tool for diagnosis, although clinical signs and symptoms of IAC and CCA are similar. Experimental steroid treatment can be useful in the diagnosis for certain difficult cases.

Retrospective evaluation of endoscopic stenting of combined malignant common bile duct and gastric outlet-duodenum obstructions

Malignant dual obstruction in the common bile duct and gastric outlet-duodenum can cause difficulties in palliative treatment. The purpose of this study was to summarize our successful experience with the endoscopic stenting procedure for the palliative treatment of malignant biliary and gastric outlet-duodenum obstruction. Seventeen patients who underwent dual stenting procedures for the common bile duct and duodenum were retrospectively reviewed. The success rate of placement, palliative effect for biliary and duodenal obstruction, incidence of complication and restricture and stent patency were analyzed. Stent placement achieved a 100% success rate. Total bilirubin decreased from 263.4±62.5 to 157.6±25.1 μmol/l, direct bilirubin decreased from 233.2±66.5 to 130.9±27.7 μmol/l and alkaline phosphatase from 534.2±78.7 to 216.3±23.3 IU/l. The differences between the preoperative and postoperative results were statistically significant (P<0.01). The gastric outlet obstruction score increased significantly from 0.9±1.1 to 2.1±0.7 points (P<0.01). The general nutritional status of the patients was improved. No serious complications occurred in any of the patients, and the survival time of patients following stenting ranged between 70 and 332 days with a mean survival time of 192 days. In conclusion, our methodology for combined biliary and enteral stenting is highly effective for the palliation of malignant biliary and gastric outlet-duodenal obstruction.

A novel PTEN gene promoter mutation and untypical Cowden syndrome

Cowden syndrome (CS), an autosomal dominant disorder, is one of a spectrum of clinical disorders that have been linked to germline mutations in the phosphatase and tensin homolog (PTEN) gene. Although 70-80% of patients with CS have an identifiable germline PTEN mutation, the clinical diagnosis presents many challenges because of the phenotypic and genotypic variations. In the present study, we sequenced the exons and the promoter of PTEN gene, mutations and variations in the promoter and exons were identified, and a PTEN protein expression negative region was determined by immunohistochemistry (IHC). In conclusion, a novel promoter mutation we found in PTEN gene may turn off PTEN protein expression occasionally, leading to the disorder of PTEN and untypical CS manifestations.

Epidermal growth factor receptor overexpression is a marker for adverse pathologic features in papillary thyroid carcinoma

BACKGROUND

Epidermal growth factor receptor (EGFR) overexpression (EGFR-H) is implicated in thyroid carcinoma disease progression; however, the clinicopathologic significance of EGFR-H in tumors that harbor EGFR and/or v-Raf murine sarcoma viral oncogene homolog B1 (BRAF)(V600E) mutations is unknown.

METHODS

Tissue microarrays from 81 patients who had undergone thyroidectomy for carcinoma from 2002-2011 were scored for EGFR expression using immunohistochemistry. Somatic mutations in EGFR exons 19 and 21 and BRAF were analyzed. Correlations between the EGFR immunohistochemistry, EGFR, and BRAF(V600E) mutations and the clinicopathologic features were assessed.

RESULTS

EGFR-H was detected in 39.5% of carcinomas (n = 32) from patients with papillary (PTC, 46.2%, n = 18), follicular (29.6%, n = 8), and anaplastic (100.0%, n = 6) but not medullary (0.0%, n = 9) thyroid carcinoma. BRAF(V600E) mutations were identified in 22.2% of the carcinoma cases (n = 18, 15 PTCs and 3 anaplastic thyroid carcinomas). No somatic EGFR mutations were detected in any subtype. On PTC univariate analysis, EGFR-H correlated with increasing stage, extrathyroid extension, tumor capsule invasion, adverse pathologic features (any demonstration of extrathyroid extension, tumor capsule invasion, lymphovascular invasion, lymph node metastasis, and/or distant metastasis), and BRAF(V600E) mutations. On multivariate analysis, EGFR-H correlated with BRAF(V600E) mutations. In BRAF wild-type PTCs, the correlation between EGFR-H and adverse pathologic features approached statistical significance (P = 0.065).

CONCLUSIONS

EGFR-H could be an important biomarker for aggressive PTCs, particularly in BRAF wild-type PTCs. Despite EGFR-H in PTC, follicular thyroid carcinoma, and anaplastic thyroid carcinoma by immunohistochemistry, somatic EGFR mutations were absent. Therefore, future investigations of EGFR should consider histologic and immunohistochemical methods, in addition to molecular profiling of thyroid carcinomas. This multimodal approach is particularly important for future clinical trials testing anti-EGFR therapy.