Ras p21 protein immunoreactivity and its relationship to p53 expression and prognosis in gallbladder and extrahepatic biliary carcinoma

Molecular assessment of c-H-ras p21 expression in Helicobacter pylori-mediated gastric carcinogenesis

Helicobacter pylori (H. pylori) infection plays a significant role in causing gastric cancer; the exact molecular mechanisms of gastric carcinogenesis have not yet been fully determined. Therefore, this study was planned to examine the role of c-H-ras p21 expression in H. pylori infection at different stages of disease progression from precursor lesions to gastric carcinoma. This study was carried out in 200 patients, consisting of normal gastric mucosa (n = 20), mucosa with chronic gastritis (n = 63), intestinal metaplasia (n = 20), dysplasia (n = 11), and gastric adenocarcinoma (n = 86), in which the H. pylori status have been analysed. The expression of c-H-ras p21 was studied at mRNA as well as protein level using RT-PCR and western blotting, respectively. The localization of c-H-ras p21 was also studied semiquantitatively by immunohistochemistry. The RT-PCR and western blotting results of c-H-ras p21 mRNA and protein expressions were significantly increased in chronic gastritis, intestinal metaplasia, dysplasia, and gastric adenocarcinoma patients, respectively. Immunohistochemical study also showed the increased expression of c-H-ras p21 in the similar way. Overexpression of c-H-ras p21 might be due to H-ras mutation at codon 12 of ras gene family in H. pylori infection. The rate of expression of ras p21 was higher in the H. pylori-infected precursor lesions, chronic gastritis 49/56 (87.5%), intestinal metaplasia 16/17 (94%), and dysplasia 9/11(82%) whereas in the case of H. pylori negative cases these groups, show 12.5, 5.9, and 18.2%, respectively. The data suggested that H. pylori infection may increase the expression of c-H-ras p21 early in the process of gastric carcinogenesis.

Prognostic molecular markers in cholangiocarcinoma: a systematic review

The worldwide incidence of cholangiocarcinoma (CC) is steadily rising, with the incidence in United Kingdom (UK) now exceeding 1000 cases per year. It is an aggressive malignancy typified by unresponsiveness to the existing chemotherapy and radiotherapy regimes in the vast majority of cases. Surgery offers the only hope of a cure, though post-operative disease recurrence is common, with 5-year survival rates of less than 25% following resection. Developments in molecular techniques and improved understanding of the basis of carcinogenesis in CC has led to examination of the role of biomarkers in predicting poor outcome. This systematic review examines published evidence relating to the prognostic significance of these molecular markers in CC. Of the molecular markers which have been investigated to date, p53 mutation, cyclins, proliferation indices, mucins, CA19-9, CRP and aneuploidy appear to hold significant potential as predictors of outcome in CC. These and other biomarkers may themselves represent novel therapeutic targets for CC.

Diagnosis of biliary tract lesions by histological sectioning of brush bristles as alternative to cytological smearing

AIM

To increase the diagnostic potential of endoscopic biliary tract brushing, we devised an approach alternative to cytological smearing, leading to the preoperative histological examination of the collected material.

METHODS

One hundred twelve consecutive biliary brush specimens were included. All patients presented a stricture of the biliary tract, leading to a diagnostic procedure by brushing. Immediately following brushing, the endoscopist immersed the brush into methanol and sent it to the pathology laboratory. The brush was introduced into a cassette for paraffin embedding and sections parallel to the long axis of brush were cut until the metal wire was almost reached, then the block was rotated and new sections were obtained from the opposite side. Samples of the mucosa, inflammatory cell aggregates, small fragments of carcinomas, or isolated cells were observed, and displayed an optimal fixation, allowing a definite diagnosis that proved mandatory for therapy in the vast majority of cases (99.1%).

RESULTS

The results obtained in 112 consecutive cases using such technique compared with final histological diagnosis proved: 91% sensitivity, 100% specificity, 100% positive predictive value (PPV), and 87% negative predictive value (NPV) (P < 0.001). In nonoperated patients, the clinical diagnosis after at least 6 months of follow-up showed: 95.5% sensitivity, 100% specificity, 100% PPV, and 88.2% NPV (P < 0.001).

CONCLUSION

Such novel approach to the preoperative diagnosis of biliary tract lesions proved to be highly sensitive and specific, limiting the inadequate preoperative diagnoses to less than 1%.

Biliary intraepithelial neoplasia: an international interobserver agreement study and proposal for diagnostic criteria

Cholangiocarcinoma of the intrahepatic and extrahepatic bile ducts develops through a multistep histopathologic sequence. Premalignant or non-invasive neoplastic lesions of bile ducts have been historically called biliary dysplasia or atypical biliary epithelium. To this date, no standard terminology or classification system has been offered for these lesions. In 2005, a conceptual framework and diagnostic criteria for biliary intraepithelial neoplasia (BilIN) were proposed using the livers of patients with hepatolithiasis. We report herein an international interobserver agreement study on the diagnosis of biliary non-invasive neoplastic lesions with the goal to obtain a consensus on the terminology and grading. Seventeen pathologists from the United States, Europe and Asia participated in this study. They shared a digital file containing histological pictures of 30 foci of non-invasive neoplastic lesions selected from the biliary system of patients suffering from primary sclerosing cholangitis, choledochal cyst or hepatolithiasis. In the criteria, we proposed in 2005, BilIN was classified into three categories based on the degree of atypia: BilIN-1, BilIN-2 and BilIN-3. In this study, consensus was reached for the terminology of BilIN and the three-grade classification system. Interobserver agreement on the diagnosis was moderate (kappa-value=0.45). On the basis of the suggestions and opinions obtained from the 17 participants, the original criteria for BilIN were revised. We now propose a new consensus classification of BilIN that may assist in allowing a more uniform terminology for the diagnosis of biliary non-invasive neoplastic lesions. This classification should help to advance clinical and research applications.

Is postoperative adjuvant chemotherapy useful for gallbladder carcinoma? A phase III multicenter prospective randomized controlled trial in patients with resected pancreaticobiliary carcinoma

BACKGROUND

To the authors' knowledge, the significance of postoperative adjuvant chemotherapy in pancreaticobiliary carcinoma has not yet been clarified. A randomized controlled study evaluated the effect of postoperative adjuvant therapy with mitomycin C (MMC) and 5-fluorouracil (5-FU) (MF arm) versus surgery alone (control arm) on survival and disease-free survival (DFS) for each specific disease comprising resected pancreaticobiliary carcinoma (pancreatic, gallbladder, bile duct, or ampulla of Vater carcinoma) separately.

METHODS

Between April 1986 and June 1992, a total of 508 patients with resected pancreatic (n = 173), bile duct (n = 139), gallbladder (n = 140), or ampulla of Vater (n = 56) carcinomas were allocated randomly to either the MF group or the control group. The MF group received MMC (6 mg/m(2) intravenously [i.v.]) at the time of surgery and 5-FU (310 mg/m(2) i.v.) in 2 courses of treatment for 5 consecutive days during postoperative Weeks 1 and 3, followed by 5-FU (100 mg/m(2)orally) daily from postoperative Week 5 until disease recurrence. All patients were followed for 5 years.

RESULTS

After ineligible patients were excluded, 158 patients with pancreatic carcinoma (81 in the MF group and 77 in the control group), 118 patients with bile duct carcinoma (58 in the MF group and 60 in the control group), 112 patients with gallbladder carcinoma (69 in the MF group and 43 in the control group), and 48 patients with carcinoma of the ampulla of Vater (24 in the MF group and 24 in the control group) were evaluated. Good compliance (> 80%) was achieved with MF treatment. The 5-year survival rate in gallbladder carcinoma patients was significantly better in the MF group (26.0%) compared with the control group (14.4%) (P = 0.0367). Similarly, the 5-year DFS rate of patients with gallbladder carcinoma was 20.3% in the MF group, which was significantly higher than the 11.6% DFS rate reported in the control group (P = 0.0210). Significant improvement in body weight compared with the control was observed only in patients with gallbladder carcinoma. There were no apparent differences in 5-year survival and 5-year DFS rates between patients with pancreatic, bile duct, or ampulla of Vater carcinomas. Multivariate analyses demonstrated a tendency for the MF group to have a lower risk of mortality (risk ratio of 0.654; P = 0.0825) and recurrence (risk ratio of 0.626; P = 0.0589). The most commonly reported adverse drug reactions were anorexia, nausea/emesis, stomatitis, and leukopenia, none of which were noted to be serious.

CONCLUSIONS

The results of the current study indicate that gallbladder carcinoma patients who undergo noncurative resections may derive some benefit from systemic chemotherapy. However, alternative modalities must be developed for patients with carcinomas of the pancreas, bile duct, or ampulla of Vater.

Detection of telomerase activity in biopsy specimens for diagnosis of biliary tract cancers

BACKGROUND

Telomerase activity is detectable in more than 85% of primary cancers. We determined telomerase activity in biopsy specimens obtained from biliary tract cancers to evaluate the clinical application of telomerase activity detection in combination with p53 immunostaining and routine histologic examination.

METHODS

Biopsy specimens obtained during percutaneous transhepatic cholangioscopy from 13 patients with cholangiocarcinoma, 3 patients with gallbladder carcinoma, and 4 patients with intrahepatic bile duct stones were evaluated by routine histologic examination, p53 immunostaining, and telomerase activity. Semiquantitative determination of telomerase activity was performed using a fluorescence-based telomeric repeat amplification protocol.

RESULTS

Thirteen of 16 specimens of malignant tissue had detectable telomerase activity, whereas no specimen of nonmalignant tissue had detectable telomerase activity. A p53 overexpression was recognized by immunostaining in 9 of 16 samples with cancers. Combining both telomerase activity and p53 overexpression resulted in the detection of all cancer with a sensitivity of 100%. There were no false-positive results by either modality (specificity 100%).

CONCLUSIONS

The detection of telomerase activity in biopsy specimens and p53 overexpression in combination with routine histologic examination may improve the diagnosis of biliary tract cancers. (Gastrointest Endosc 2000;52:380-6).

Overexpression of p53 protein in gallbladder carcinoma in North India

AIMS

p53 mutations are one of the most frequent genetic alterations in human cancers and are thought to play a role in pathogenesis of several malignancies. Overexpression of p53 in gallbladder cancer has not previously been reported from North India which has one of the highest incidence of this malignancy in the world. The present work is aimed at studying the overexpression of p53 in gallbladder carcinoma occurring in North India.

METHODS

p53 overexpression by immunohistochemistry was studied in 20 operative specimens of gallbladder carcinoma. The clinico-pathological observations of these patients were correlated with the extent of p53 overexpression.

RESULTS

Seventy per cent (14/20) of specimens of gallbladder carcinoma overexpressed p53 protein. There was a significant correlation between presence of gallstones, T stage, grade of tumour and liver invasion with p53 overexpression. There was no significant correlation with other factors studied viz. age, sex, nodal status and histological type.

CONCLUSIONS

The results show a strong association between gallstones and p53 protein overexpression in gallbladder carcinoma. The causal relationship in this association, however, still remains unproven.