p53 protein overexpression in gallbladder carcinoma and its precursor lesions: an immunohistochemical study

Single-cell analyses unravel ecosystem dynamics and intercellular crosstalk during gallbladder cancer malignant transformation

BACKGROUND

Gallbladder cancer (GBC) is a rare but aggressive malignancy, often detected late due to early asymptomatic stages. Understanding cellular and molecular changes from normal tissue to high-grade intraepithelial neoplasia (HGIN) and invasive GBC is vital for identifying early biomarkers and therapeutic targets.

METHODS

We performed single-cell RNA sequencing on 98,113 cells derived from 2 normal adjacent tissues (NAT), 2 HGIN, and 6 GBC samples. The cellular diversity and heterogeneity, particularly within epithelial and immune cell populations in NAT-HGIN-GBC, were investigated utilizing single-cell RNA sequencing, bulk RNA sequencing (bulk RNA-seq), and 10 machine learning methodologies. Furthermore, the intercellular crosstalk between epithelial cells and tumor immune microenvironment cells was examined and validated through multiplex immunofluorescence staining.

RESULTS

The constructed cell atlas elucidated alterations in the immune landscape across various states of NAT-HGIN-GBC, highlighting a more pronounced inhibitory immune microenvironment in GBC. The epithelial subtype TOP2A+ Epi is markedly elevated in GBC and is correlated with a poor prognosis. Key genes associated with this subtype may include GMNN, CYTOR, KLK6, and BIRC5. Similarly, immunosuppressive macrophages, identified as TOP2A+ Macro, also increase along the NAT-HGIN-GBC sequence and are linked to reduced patient survival. Furthermore, TOP2A+ Macro and CD8+ exhausted T cells (CD8+ Tex) engage in intercellular communication with epithelial TOP2A+Epi cells via the TWEAK/FN14 signaling pathway, thereby promoting tumor progression and immune evasion in GBC. The findings were further corroborated through multiplex immunofluorescence staining conducted on specimens from patients.

CONCLUSIONS

This study elucidates significant alteration in the cellular ecosystems and intercellular signaling within the tumor immune microenvironment across the NAT-HGIN-GBC sequence. It identifies TOP2A, TWEAK, and FN14 as potential biomarkers and therapeutic targets for GBC.

Utility of IMP3, p53, and S100P immunohistochemical stains in distinguishing reactive atypia from dysplasia in cholecystectomy specimens

BACKGROUND

Distinguishing reactive atypia from dysplasia in cholecystectomy specimens can be histologically challenging. The aim of this study was to evaluate the utility of IMP3, p53, and S100P immunostains in differentiating reactive atypia from dysplasia in cholecystectomies.

METHODS

Fifty-four cholecystectomies were reviewed and characterized into 5 groups: 2 normal, 29 reactive atypia, 16 low-grade dysplasia, 2 high-grade dysplasia, and 5 adenocarcinoma. IMP3, p53, and S100P immunostains were performed and evaluated. IMP3 (nuclear) and S100P (nuclear or nuclear/cytoplasmic) were categorized into negative or positive expression, and p53 was categorized into wild-type and aberrant/mutant expression. Chi-square test was used for statistical analysis.

RESULTS

The patients were mostly middle-aged women (mean 44, range 19-87 years, 81% female), with predominantly Hispanic White ethnicity (80%). The majority of the normal and reactive atypia cases showed negative IMP3 (100% and 75.9%, respectively) and wild-type p53 (100% and 89.7%, respectively) staining. Over half (56.3%) of the low-grade dysplasia and all the high-grade dysplasia cases showed IMP3 positivity. Aberrant p53 staining pattern was seen in half of both low and high-grade dysplasia cases. Adenocarcinoma showed IMP3 positivity in 80% and p53 aberrancy in all cases. S100P showed no statistical significance among the diagnostic categories. Significant differences in staining patterns were found between reactive atypia vs. low-grade dysplasia, and reactive atypia vs. low-grade + high-grade dysplasia using a combination of IMP3 and p53 stains (all p < 0.05).

CONCLUSIONS

In challenging cholecystectomies, IMP3 positivity or aberrant p53 expression may serve as a useful adjunct to support a diagnosis of dysplasia over reactive atypia.

Spatial transcriptomics profiling of gallbladder adenocarcinoma: a detailed two-case study of progression from precursor lesions to cancer

BACKGROUND

Most studies on tumour progression from precursor lesion toward gallbladder adenocarcinoma investigate lesions sampled from distinct patients, providing an overarching view of pathogenic cascades. Whether this reflects the tumourigenic process in individual patients remains insufficiently explored. Genomic and epigenomic studies suggest that a subset of gallbladder cancers originate from biliary intraepithelial neoplasia (BilIN) precursor lesions, whereas others form independently from BilINs. Spatial transcriptomic data supporting these conclusions are missing. Moreover, multiple areas with precursor or adenocarcinoma lesions can be detected within the same pathological sample. Yet, knowledge about intra-patient variability of such lesions is lacking.

METHODS

To characterise the spatial transcriptomics of gallbladder cancer tumourigenesis in individual patients, we selected two patients with distinct cancer aetiology and whose samples simultaneously displayed multiple areas of normal epithelium, BilINs and adenocarcinoma. Using GeoMx digital spatial profiling, we characterised the whole transcriptome of a high number of regions of interest (ROIs) per sample in the two patients (24 and 32 ROIs respectively), with each ROI covering approximately 200 cells of normal epithelium, low-grade BilIN, high-grade BilIN or adenocarcinoma. Human gallbladder organoids and cell line-derived tumours were used to investigate the tumour-promoting role of genes.

RESULTS

Spatial transcriptomics revealed that each type of lesion displayed limited intra-patient transcriptomic variability. Our data further suggest that adenocarcinoma derived from high-grade BilIN in one patient and from low-grade BilIN in the other patient, with co-existing high-grade BilIN evolving via a distinct process in the latter case. The two patients displayed distinct sequences of signalling pathway activation during tumour progression, but Semaphorin 4 A (SEMA4A) expression was repressed in both patients. Using human gallbladder-derived organoids and cell line-derived tumours, we provide evidence that repression of SEMA4A promotes pseudostratification of the epithelium and enhances cell migration and survival.

CONCLUSION

Gallbladder adenocarcinoma can develop according to patient-specific processes, and limited intra-patient variability of precursor and cancer lesions was noticed. Our data suggest that repression of SEMA4A can promote tumour progression. They also highlight the need to gain gene expression data in addition to histological information to avoid understimating the risk of low-grade preneoplastic lesions.

Intracholecystic papillary neoplasm acquiring malignant characteristics and leading to multiple liver metastases: A case report

The mechanisms underlying the progression of intracholecystic papillary neoplasms (ICPNs) to gallbladder cancer and invasive cancer remain relatively unclear. In the present case, metastatic liver tumors were suspected in an 83-year-old man at presentation; however, the primary tumor was unknown. The patient died shortly thereafter as a result of rapid tumor progression. An autopsy revealed multiple liver, lung, and lymph node metastases. Additionally, a fragile papillary tumor with a high-grade dysplastic epithelium with tubulopapillary morphology and admixed foci of a low-grade dysplastic epithelium were detected at the fundus of the gallbladder. The well-differentiated tubular adenocarcinoma had extensively invaded the wall's granular mucosal surface along with the solitary papillary tumor. Based on pathological findings, a diagnosis of an ICPN with an associated invasive carcinoma was established. This case is novel because it showed that an ICPN can progress aggressively.

Biliary Tract Cancer: Molecular Biology of Precursor Lesions

Biliary tract cancer is a devastating malignancy of the bile ducts and gallbladder with a dismal prognosis. The study of precancerous lesions has received considerable attention and led to a histopathological classification which, in some respects, remains an evolving field. Consequently, increasing efforts have been devoted to characterizing the molecular pathogenesis of the precursor lesions, with the aim of better understanding the mechanisms of tumor progression, and with the ultimate goal of meeting the challenges of early diagnosis and treatment. This review delves into the molecular mechanisms that initiate and promote the development of precursor lesions of intra- and extrahepatic cholangiocarcinoma and of gallbladder carcinoma. It addresses the genomic, epigenomic, and transcriptomic landscape of these precursors and provides an overview of animal and organoid models used to study them. In conclusion, this review summarizes the known molecular features of precancerous lesions in biliary tract cancer and highlights our fragmentary knowledge of the molecular pathogenesis of tumor initiation.

Incidence, Mortality, and Survival Trends in Cancer of the Gallbladder and Extrahepatic Bile Ducts in Lithuania

Background and Objectives: Gallbladder cancer is a rare type of cancer, with aggressive clinical behavior. Limited treatment options provide poor survival prognosis. We aimed to investigate the incidence, mortality trends, and survival of gallbladder and extrahepatic bile duct cancer in Lithuania between 1998 and 2017. Materials and Methods: The study was based on the Lithuanian Cancer Registry database. The study included all cases of cancer of the gallbladder and extrahepatic bile ducts reported to the Registry in the period 1998–2017. Age-specific and age-standardized incidence rates were calculated. In addition, 95% confidence intervals for APC (Annual Percent Change) were calculated. Changes were considered statistically significant if p was <0.05. Relative survival estimates were calculated using period analysis according to the Ederer II method. Results: Age-standardized rates for gallbladder cancer and extrahepatic bile duct cancer among females decreased from 3.91 to 1.93 cases per 100.000 individuals between 1998 and 2017, and from 2.32 to 1.59 cases per 100.000 individuals between 1998 and 2017 among males. The highest incidence rates were found in the 85+ group with 27.5/100,000 individuals in females and 26.8/100,000 individuals in males. The 1-year as well as 5-year relative survival rates of both genders were 34.29% (95% CI 32.12–36.48) and 16.29% (95% CI 14.40–18.27), respectively. Conclusions: Incidence and mortality from gallbladder and extrahepatic bile duct cancer decreased in both sexes in Lithuania. Incidence and mortality rates were higher in females than in males. Relative 1-year and 5-year survival rates showed a steady increase during the study period among males and females.

Gallbladder carcinomas: review and updates on morphology, immunohistochemistry, and staging

Gallbladder is a common surgical pathology specimen. However, carcinomas of the gallbladder are relatively rare in most western countries. Hence, general surgical pathologists may not be that familiar and comfortable diagnosing these tumors. In this review, we discuss the morphological and immunohistochemical characteristics of gallbladder carcinomas, provide updates on tumor classification and staging of these tumors as per the most recent WHO classification, and focus on practical considerations that would be most relevant to diagnosis and clinical management of these tumors.

Understanding the mechanisms of gallbladder lesions: A systematic review

The gallbladder undergoes different types of pathologies, ranging from inflammatory to preneoplasia and finally to malignant lesions. Gallbladder carcinoma can be highly invasive, and it is known that chronic inflammation of the gallbladder can lead to preneoplastic abnormalities and subsequently malignant phenotypes. Gallbladder neoplasia has a low incidence but is associated with a very poor prognosis. An early diagnosis is therefore extremely important in order to improve the prognosis of patients. Immunohistochemical markers of the mucin family can distinguish between different types of gallbladder lesions. Mucins are glycoproteins that can be attached to threonine residues that are O-glycosylated (due to the hydroxyl group of this amino acid). Mucins are divided into two types: those that bind to the membrane, such as MUC1, and those that form gels or are secreted, such as MUC5AC. Various alterations in mucin expression have been revealed to be associated with the development of neoplasia, as they modulate cell growth, karyokinetic transformation, dedifferentiation, adhesion, invasion and immune surveillance. p53 is a tumor suppressor gene and is linked to the development of different types of neoplasia. The incidence of the p53 gene is variable in the pathophysiology of gallbladder cancer. Several studies have revealed an incidence of ~50% of the p53 gene in gallbladder tumors. Studying the immunohistochemical profile of mucins and the presence of different gene mutations in neoplastic lesions of the gallbladder and surrounding mucosa may contribute to the understanding of the pathophysiology of the disease and the mechanisms involved in tumor development, allowing the identification of patients at increased risk of developing neoplasia, thus leading to improved management.

Evolving Paradigms in the Systemic Treatment of Advanced Gallbladder Cancer: Updates in Year 2022

Gallbladder cancer (GBC) is a biological, anatomical, and clinically distinct subset of biliary tract cancers (BTC), which also include extra- and intra-hepatic cholangiocarcinoma. The advent of next-generation sequencing (NGS) clearly shows that GBC is genetically different from cholangiocarcinoma. Although GBC is a relatively rare cancer, it is highly aggressive and carries a grave prognosis. To date, complete surgical resection remains the only path for cure but is limited to patients with early-stage disease. The majority of the patients are diagnosed at an advanced, inoperable stage when systemic treatment is administered as an attempt to enable surgery or for palliation. Gemcitabine and platinum-based chemotherapies have been the main treatment modality for unresectable, locally advanced, and metastatic gallbladder cancer. However, over the past decade, the treatment paradigm has evolved. These include the introduction of newer chemotherapeutic strategies after progression on frontline chemotherapy, incorporation of targeted therapeutics towards driver mutations of genes including HER2, FGFR, BRAF, as well as approaches to unleash host anti-tumor immunity using immune checkpoint inhibitors. Notably, due to the rarity of BTC in general, most clinical trials included both GBC and cholangiocarcinomas. Here, we provide a review on the pathogenesis of GBC, past and current systemic treatment options focusing specifically on GBC, clinical trials tailored towards its genetic mutations, and emerging treatment strategies based on promising recent clinical studies.

An overview on possible links between aflatoxin B1 exposure and gallbladder cancer

Gallbladder cancer (GBC) is one of the most common sites for biliary tract cancers. It has a worldwide distribution being endemic in South America and Southern Asia. These high GBC rates have previously been linked to the determinants of health such as nutrition, genetics, lifestyle, and environment. Exposure to aflatoxin B₁ (AFB₁), a human carcinogen, is suggested to be involved with GBC development. This work aims to analyse the interplay of social, lifestyle, and genetic predisposing factors to GBC. AFB₁ plays a pivotal role in carcinogenic onset by genetic and epigenetic modifications. AFB₁ can induce molecular changes involved in the GBC pathogenesis, such as overexpression of UCHL1 gene, mutagenesis of TP53 gene, abnormal expression of oncogenes BCL-2, and aberrantly methylation of ERBB family receptors. However, a large-scale scientific cooperation is needed to confirm these molecular links through which AFB₁ may increase the GBC risk. For that, monitoring AFB₁ exposure through AF-albumin and AFB1-lysine will clarify the level of exposure of the population to AFB₁ in the GBC hotspot. Further, analyses of AFB1-adduct concentrations in GBC cases (fatal and non-fatal) are needed to understanding if AF contamination can trigger gallbladder cancer.

Molecular Oncology of Gall Bladder Cancer

Gall bladder carcinoma (GBC) is a worldwide problem, with a higher incidence in areas of the world where cholelithiasis is common. As GBC is usually diagnosed in an advanced stage, the mortality is high. An understanding of the molecular pathways of carcinogenesis and the mutations involved in the development and progression of GBC could be useful in early diagnosis. Understanding molecular markers of prognosis as well as predictors of outcome could also potentially benefit patients undergoing treatment. New therapies targeting major molecular pathways and immunotherapy are exciting novel therapeutic options. This review focuses on the current understanding of the molecular oncology of GBC.

Prognostic implications of the coexisting precursor lesion types in invasive gallbladder cancer

Invasive gallbladder carcinoma (GBC) is preceded by two main types of precursor lesions: intracholecystic papillary-tubular neoplasms (ICPNs) and biliary intraepithelial neoplasias (BilINs). Invasive GBCs with an ICPN component have more favorable prognoses than those without an ICPN component. Some BilINs show a relatively exophytic papillary pattern but do not meet the ICPN criteria; at our institution, we call these papillary neoplasias. To clarify the clinical significance of papillary neoplasia, we herein examined 80 invasive GBCs and classified them into three groups based on the type of preinvasive lesions: those with ICPN (ICPN group, n = 35), those with papillary neoplasia (pap-neoplasia group, n = 13), and those without ICPN/papillary neoplasia (group without ICPN/pap-neoplasia, n = 32). We then compared the prognostic differences and characterized the tumors of each group by determining the immunohistochemical expressions of various biomarkers. The overall survival periods of the ICPN and pap-neoplasia groups were significantly longer than that of the group without ICPN/pap-neoplasia (P < 0.0001, P = 0.0036, respectively). Multivariate analysis revealed that lacking ICPN/papillary neoplasia was independently associated with poor prognosis (P = 0.0007), as were poor differentiation (P = 0.0395), presence of preoperative symptoms (P = 0.0488), and advanced stage (P = 0.0234). Invasive components of the ICPN and pap-neoplasia groups were characterized by higher expressions of p16 and p53 compared with those of the group without ICPN/pap-neoplasia. The prognoses of the invasive GBCs with either papillary neoplasia or ICPN were thus more favorable than those of the invasive GBCs without ICPN/pap-neoplasia. Invasive GBCs with exophytic papillary preinvasive lesions (ICPN and papillary neoplasia) may be biologically different from those without such lesions.

Dysplasia and carcinoma of the gallbladder: pathological evaluation, sampling, differential diagnosis and clinical implications

Pathological evaluation of gallbladder neoplasia remains a challenge. A significant proportion of cases presents as clinically and grossly inapparent lesions, and grossing protocols are not well established. Among epithelial alterations, pseudo-pyloric gland metaplasia is ubiquitous and of no apparent consequence, whereas goblet cell metaplasia and a foveolar change in surface cells require closer attention. Low-grade dysplasia is difficult to objectively define and appears to be clinically inconsequential by itself; however, extra sampling is required to exclude the possibility of accompanying more significant lesions. For high-grade dysplasia ('high-grade BilIN', also known as 'carcinoma in situ'), a complete sampling is necessary to rule out invasion. Designating in-situ or minimally invasive carcinomas limited to muscularis or above as early gallbladder carcinoma (EGBC) helps to alleviate the major geographical differences (West/East) in the criteria for 'invasiveness' to assign a case to pTis or pT1. Total sampling is crucial in proper diagnosis of such cases. A subset of invasive GBCs (5-10%) arise from the intracholecystic neoplasm (ICN, 'adenoma-carcinoma sequence') category. Approximately two-thirds of ICNs have invasive carcinoma. However, this propensity differs by subtype. True 'pyloric gland adenomas' (> 1 cm) are uncommon and scarcely associated with invasive carcinoma. A distinct subtype of ICN composed of tubular, non-mucinous MUC6⁺ glands [intracholecystic tubular non-mucinous neoplasm (ICTN)] forms a localised pedunculated polyp. Although it is morphologically complex and high-grade, it appears to be invasion-resistant. Some of the invasive carcinoma types in the gallbladder have been better characterised recently with adenosquamous, neuroendocrine, poorly cohesive and mucinous carcinomas often being more advanced and aggressive.

Functional and genomic characterization of three novel cell lines derived from a metastatic gallbladder cancer tumor

Background

Gallbladder cancer (GBC) is the most common tumor of the biliary tract. The incidence of GBC shows a large geographic variability, being particularly frequent in Native American populations. In Chile, GBC represents the second cause of cancer-related death among women. We describe here the establishment of three novel cell lines derived from the ascitic fluid of a Chilean GBC patient, who presented 46% European, 36% Mapuche, 12% Aymara and 6% African ancestry.

Results

After immunocytochemical staining of the primary cell culture, we isolated and comprehensively characterized three independent clones (PUC-GBC1, PUC-GBC2 and PUC-GBC3) by short tandem repeat DNA profiling and RNA sequencing as well as karyotype, doubling time, chemosensitivity, in vitro migration capability and in vivo tumorigenicity assay. Primary culture cells showed high expression of CK7, CK19, CA 19-9, MUC1 and MUC16, and negative expression of mesothelial markers. The three isolated clones displayed an epithelial phenotype and an abnormal structure and number of chromosomes. RNA sequencing confirmed the increased expression of cytokeratin and mucin genes, and also of TP53 and ERBB2 with some differences among the three cells lines, and revealed a novel exonic mutation in NF1. The PUC-GBC3 clone was the most aggressive according to histopathological features and the tumorigenic capacity in NSG mice.

Conclusions

The first cell lines established from a Chilean GBC patient represent a new model for studying GBC in patients of Native American descent.

Molecular pathways and potential biomarkers in gallbladder cancer: A comprehensive review

The most common malignancy of the biliary tract, gallbladder cancer (GBC) often has a dismal prognosis. The aggressive nature of the tumor, delayed diagnosis at advanced stages of the disease, and lack of effective treatment options are some of the factors that contribute to a poor outcome. Early detection and accurate assessment of disease burden is critical to optimize management and improve long-term survival, as well as identify patients for adjuvant therapy and clinical trials. With recent advances in the understanding of the molecular pathogenesis of GBC, several specific diagnostic and biomarkers have been proposed as being of diagnostic and prognostic importance. Indeed, identification of novel diagnostic and prognostic markers has an important role in early diagnosis and development of targeted therapies among patients with GBC. Next-generation sequencing technology and genomewide data analysis have provided novel insight into understanding the molecular pathogenesis of biliary tract cancers, thereby identifying potential biomarkers for clinical use. We herein review available GBC biomarkers and the potential clinical implications in the management of GBC.

Epidemiology of gallbladder cancer

According to GLOBOCAN 2018 data, gallbladder cancer (GBC) accounts for 1.2% of all global cancer diagnoses, but 1.7% of all cancer deaths. Only 1 in 5 GBC cases in the United States is diagnosed at an early stage, and median survival for advanced stage cancer is no more than about a year. The incidence of the disease is increasing in the developed world. Gallstones, biliary cysts, carcinogen exposure, typhoid, and Helicobacter pylori infection, and abnormal pancreaticobiliary duct junctions are all risk factors, many of which account for its geographical, ethnic and sex distribution. Genetics also plays a strong role, as about a quarter of GBC cases are considered familial, and certain ethnicities, such as Native Americans, are at far higher risk for the neoplasm. Prevention includes weight loss, vaccination against and treatment of bacterial infections, early detection and elimination of polyps and cysts, and avoidance of oral estrogen replacement therapy.

A genetic model for gallbladder carcinogenesis and its dissemination

Gallbladder cancer, although regarded as the most common malignancy of the biliary tract, continues to be associated with a dismal overall survival even in the present day. While complete surgical removal of the tumour offers a good chance of cure, only a fraction of the patients are amenable to curative surgery owing to their delayed presentation. Moreover, the current contribution of adjuvant therapies towards prolonging survival is marginal, at best. Thus, understanding the biology of the disease will not only enable a better appreciation of the pathways of progression but also facilitate the development of an accurate genetic model for gallbladder carcinogenesis and dissemination. This review provides an updated, evidence-based model of the pathways of carcinogenesis in gallbladder cancer and its dissemination. The model proposed could serve as the scaffolding for elucidation of the molecular mechanisms involved in gallbladder carcinogenesis. A better understanding of the pathways involved in gallbladder tumorigenesis will serve to identify patients at risk for the cancer (and who thus could be offered prophylactic cholecystectomy) as well as aid oncologists in planning the most suitable treatment for a particular patient, thereby setting us on the vanguard of transforming the current treatment paradigm for gallbladder cancer.

Mitotic count reflects prognosis of gallbladder cancer particularly among patients with T3 tumor

The surgical strategy for gallbladder cancer (GBC) depends on the extent of the disease. Thus, the identification of useful prognostic markers exerting strong prognostic impact for each T stage would be beneficial in the development of rational therapeutic strategies. The purpose of this study was to identify useful prognostic markers of GBC for each T stage. CD8⁺ tumor-infiltrating lymphocytes (TIL), Ki-67 labeling index (LI), p53 nuclear expression and mitotic count (MC) were investigated as candidate prognostic markers. In total, 86 patients with invasive GBC were included. Of the prognostic markers examined, only MC showed a correlation with reduced survival (P=0.0383) in the univariate analysis of overall T stage. In the univariate analysis of T2 stage (n=31), only high p53 expression correlated with survival showing a positive correlation (P=0.0154). In the univariate analysis of T3 stage (n=40), the only factor showing a significant correlation with survival was MC (P=0.0113). Multivariate analysis, including N and M as factors, identified only MC as an independent prognostic factor in T3 stage GBC (P=0.0419). In conclusion, this study demonstrated the strong prognostic impact of MC in GBC, particularly in patients with T3 tumor.

Precancerous lesions of the biliary tree

The neoplasms of the biliary tree include the carcinomas of the intra- and extrahepatic bile ducts, the gallbladder and the ampulla. Two types of precancerous lesions precede these adenocarcinomas: the flat and non-tumour forming type that is called biliary intraepithelial neoplasia, and the papillary and tumour-forming type that has been named intraductal papillary neoplasm of the bile duct. Rarely also biliary mucinous cystic neoplasm can give rise to invasive biliary adenocarcinomas. This review discusses the pathological, molecular, epidemiological, clinical and prognostic features of the precancerous biliary lesions, separated according to their origin in the bile ducts, the ampulla and the gall bladder.

Xanthogranulomatous cholecystitis: a clinicopathological study of its association with gallbladder carcinoma

OBJECTIVES

To determine the distribution of macrophages (MΦ) in both xanthogranulomatous cholecystitis (XGC) and gallbladder carcinoma (GBC) and to analyze the association between XGC and GBC.

METHODS

From January 2009 to June 2011, 110 patients with gallbladder diseases, including 35 with GBC, 45 with XGC and 30 with chronic cholecystitis (CC), were enrolled. Immunohistochemistry stain and real-time polymerase chain reaction using oncogenes (BCL-2, c-Myc) and anti-oncogene genes (p53, p21) were performed, serum expressions of tumor marker (CA19-9, CA724 and CA242) were also conducted. MΦ were used to determine their potential role in the carcinogenesis of GBC.

RESULTS

BCL-2 and c-Myc expressions gradually increased among CC, XGC and GBC (P = 0.032 and P = 0.020, respectively); while p53 and p21 were similar in the three groups (P = 0.167 and P = 0.122, respectively). Serum BCL-2 and c-Myc were significantly correlated with their tissue levels; in terms of serum tumor markers, which gradually increased among CC, XGC and GBC, however, CA242 and CA724 were both negative in XGC but positive in GBC. Furthermore, gradually increasing MΦ counts were observed among CC, XGC and GBC groups; c-Myc and CA724 were independent predictors for the differentiation of XGC and GBC.

CONCLUSIONS

XGC is an uncommon inflammatory condition distinct from CC and may be associated with the precancerous nature of GBC for its upregulated oncogenes and MΦ biology. c-Myc and CA724 were independent predictors for the differentiation of XGC and GBC.

Regional differences in gallbladder cancer pathogenesis: insights from a comparison of cell cycle-regulatory, PI3K, and pro-angiogenic protein expression

BACKGROUND

The variable incidence of gallbladder cancer (GBCA) suggests regional pathogenetic differences. This study compares cell cycle-regulatory, angiogenesis-related, and PI3K pathway protein expression in GBCAs from three continents.

METHODS

Immunohistochemical expression of several proteins was assessed, correlated with clinicopathologic variables, and compared among centers from Chile (Fundación Arturo López Pérez [FALP]), Japan (Yokohama City University [YCU]), and the United States (Memorial Sloan-Kettering Cancer Center [MSKCC]). Hierarchical clustering was used to partition the data based on protein-expression and treatment center.

RESULTS

Tissue from 117 patients (MSKCC = 76; FALP = 22; YCU = 19) was analyzed. Mdm2 overexpression was seen only at MSKCC (p < 0.0001). Absence of p21 (p = 0.03) and VEGFR2 (p = 0.018) were more common and p27 expression was less frequent (p = 0.047) in tumors from YCU. Ki-67 labeling index in YCU tumors (median = 10) was two-thirds lower than at other centers. On hierarchical clustering analysis, all YCU patients (p = 0.017) and those with early tumors (p = 0.017) clustered separately from MSKCC. Median disease-specific survival after curative intent (R0) resection was 27 months and was similar among centers (p = 0.9). Median disease-specific survival of patients with early tumors was 28.4 months and was higher at YCU (not reached, p = 0.06).

CONCLUSIONS

Cell cycle-regulatory protein expression patterns of YCU tumors differed from those treated at FALP and MSKCC. The differential clustering of protein expression and survival in patients with early tumors suggest regional differences in pathogenesis and disease biology.

Risk factors for gallbladder cancer and cholangiocarcinoma: similarities, differences and updates

INTRODUCTION

Far-ranging variation in the incidence of gallbladder cancer (GBC) and cholangiocarcinoma (CCA) in different geographic regions on the globe may reflect the risk factor distribution for these tumors

METHODS

The authors give a comprehensive review on the known risk factors for GBC and CCA, and analyze both similarities and differences between the risk factors for the two main types of biliary cancer

DISCUSSION AND CONCLUSION

Leading risk factors for GBC include gallstones, female gender, and advancing age. Primary sclerosing cholangitis, nitrosamine exposure, choledochal cysts, Clonorchis sinensis and Opisthorchis viverrini represent important risk factors for CCA, although a specific risk factor cannot be identified for many patients. While both cancers affect mostly individuals in their sixth decade or older, CCA has a male predominance and GBC--a predilection for females. Although the current level of understanding of the molecular pathogenesis of GBC and CCA at the interface with specific risk factors is significantly lower than for other gastrointestinal malignancies, it continues to evolve and may soon open new avenues for the therapy of biliary cancers.

Hyperplastic polyp of the gallbladder associated with pancreaticobiliary maljunction in a 9-year-old girl

The association between hyperplastic polyp of the gallbladder with pancreaticobiliary maljunction (PBM) is extremely rare. This report describes the rare case of a 9-year-old girl with PBM complicated by hyperplastic polyp of the gallbladder, and the successful surgical treatment of PBM. We review the literature on this type of relationship between hyperplastic polyp of the gallbladder and PBM, and discuss the clinical features of this complication. Furthermore, the possible cause of the onset of hyperplastic polyp of the gallbladder complicated by PBM was explored in this report.

Pancreaticobiliary maljunction and carcinogenesis to biliary and pancreatic malignancy

BACKGROUND

It is widely accepted that congenital choledochal cyst is associated with pancreaticobiliary maljunction (PBM). But, PBM is an independent disease entity from choledochal cyst. PBM is synonymous with "abnormal junction of the pancreaticobiliary ductal system", "anomalous arrangement of pancreaticobiliary ducts", "anomalous union of bilio-pancreatic ducts", etc. Cases with PBM not associated with biliary duct dilatation are often found, and these cases are frequently complicated gallbladder cancer. The Japanese Study Group of Pancreaticobiliary Maljunction was started in 1983, and defined diagnostic criteria and nationwide registration system of PBM cases was started. PBM is defined as a union of the pancreatic and biliary ducts which is located outside the duodenal wall. Bile and pancreatic juice reflux and regurgitate mutually.

BILIARY CARCINOGENESIS

The most bothersome problem is biliary carcinogenesis. Gallbladder cancers arise in 14.8% and bile duct cancers arise in 4.9%. The incidence of the gallbladder carcinoma of PBM without bile duct dilatation is 36.1%. Many investigators have tried to clarify the carcinogenic process, from various aspects. The biliary epithelia are injured by harmful substances, and in the course of repair, multiple alterations of oncogenes and tumor suppressor genes are followed, and they lead to carcinoma through multistage interaction. In the biliary epithelia of PBM, incidence and degree of hyperplasia are characteristic. K-ras gene mutations are observed in the cancerous as well as noncancerous lesions of biliary tract of PBM patients. Mutations of p53 gene and overexpression of p53 protein are also found in the cancerous and noncancerous lesions. These changes are called "hyperplasia-carcinoma sequence".

TREATMENT

Total excision of the extrahepatic bile duct with gallbladder followed by hepaticojejunostomy, Roux-en-Y, or end-to-side hepaticoduodenostomy are treatment of choice, even for cases with not dilated bile duct, because the incidence of cancer in the nondilated bile duct is not negligible, and genetic changes are seen in a nondilated bile duct.

Two distinct pathways of p16 gene inactivation in gallbladder cancer

AIM: To examine the mechanism of inactivation of the p16 gene in gallbladder cancer, and to investigate p16 alterations and their correlation with clinicopathological features.

METHODS: Specimens were collected surgically from 51 patients with gallbladder cancer. We evaluated the status of protein expression, loss of heterozygosity (LOH), homozygous deletion and promoter hypermethylation using immunohistochemistry, microsatellite analysis, quantitative real-time polymerase chain reaction (PCR) and methylation-specific PCR, respectively. In addition, mutations were examined by direct DNA sequencing.

RESULTS: Homozygous deletions of the p16 gene exon2, LOH at 9p21-22, p16 promoter hypermethylation, and loss of p16 protein expression were detected in 26.0% (13/50), 56.9% (29/51), 72.5% (37/51) and 62.7% (32/51), respectively. No mutations were found. LOH at 9p21 correlated with the loss of p16 protein expression (P < 0.05). Homozygous deletion of the p16 gene, a combination LOH and promoter hypermethylation, and multiple LOH at 9p21 were significantly correlated with the loss of p16 protein expression (P < 0.05). LOH at 9p21 and promoter hypermethylation of the p16 gene were detected in 15.4% (2/13) and 92.3% (12/13) of the tumors with homozygous deletion of the p16 gene, respectively. P16 alterations were not associated with clinicopathological features.

CONCLUSION: Our results suggest that LOH and homozygous deletion may be two distinct pathways in the inactivation of the p16 gene. Homozygous deletion, a combination of LOH and promoter hypermethylation, and multiple LOH are major mechanisms of p16 inactivation in gallbladder cancer.

Is there a role for estrogen and progesterone receptors in gall bladder cancer?

BACKGROUND/AIMS

The concept of metaplastic and non-metaplastic types of gall bladder cancer and the likelihood of hormone receptor expression in the nuclei of tumour cells raised the possibility of a potential role for anti-estrogen therapy in gall bladder cancer. This study was carried out to determine the hormone receptors (ER/PR) expression level in gall bladder cancer using specific immunohistochemical assays and correlate it with patient and tumour histopathological characteristics.

PATIENTS AND METHODS

Histopathological tumour specimens of 62 patients who underwent a radical cholecystectomy were analysed. Pronase pretreatment and primary monoclonal antibodies were used to perform immunohistochemical analysis for ER and PR.

RESULTS

The histology was adenocarcinoma--predominantly, moderately to poorly differentiated (91%). Gallstones were present in 90% of the individuals. Of the 62 specimens analysed, 62 (100%) and 61 (98%) were negative for ER and PR, respectively.

CONCLUSION

The high incidence of gallstone-related gall bladder cancer in India is associated with metaplasia and a tendency to poorer differentiation in the tumour histology. These tumours are consequently less likely to express hormone receptors. Thus, there does not seem to be a role for anti-hormone therapy in patients with histogenesis similar to that seen in India.

Biliary Tract Cancer

This chapter reviews the epidemiology of biliary tract cancer. Many etiologic leads for biliary tract cancer have come from clinical observations, autopsy series, and descriptive epidemiologic studies. While a significant fraction of these tumors are related to gallstones (cholelithiasis), information on other risk factors is limited, due to the rarity of the tumors, the often rapidly fatal course, and the small number of epidemiologic studies conducted to date. Because the three anatomic categories of biliary tract cancer have distinct epidemiologic patterns and molecular changes, including somatic mutations and loss of heterozygosity (LOH), it has been suggested that the causal factors vary by subsite.

Eosinophilic dysplasia of the gallbladder: a hitherto undescribed variant identified in association with a "porcelain" gallbladder

Non-mass forming, neoplastic intraepithelial proliferations (dysplasia) represent the most well-accepted precursor lesions to gallbladder adenocarcinomas. They are typically small, localized, grossly unrecognizable lesions that have been identified in the epithelium adjacent to up to 79% of gallbladder adenocarcinomas. Morphologic variants that have been reported include flat, micropapillary, papillary and cribriform. We have recently encountered a morphologically distinctive, previously unreported lesion to which we have applied the designation eosinophilic dysplasia. This lesion was identified in a gallbladder with diffuse mural fibrosis and calcification (porcelain gallbladder). The dysplastic focus was confined to one tissue section, and was comprised of a localized true papilla [i.e with a fibrovascular core], measuring approximately 1.2 mm in greatest dimension and an adjacent, flat, 7-cell epithelial segment. These foci were lined by cells displaying significant nuclear enlargement [1.5–4 times the adjacent benign cells], nuclear pleomorphism, occasional multinucleation, hyperchromasia and nuclear membrane irregularities. Nucleoli were present but inconspicuous. These cells also showed voluminous eosinophilic to granular cytoplasm, such that the overall nuclear-to-cytoplasmic ratio was generally not increased. The cells displayed diffuse and marked nuclear immunoreactivity for p53, and approximately 70% of the cells showed nuclear positivity for Ki-67. The cells were also positive for cytokeratin 7 and were entirely negative for carcinoembryonic antigen (CEA) and chromogranin A. The cells of the adjacent normal epithelium were positive for cytokeratin 7 and CEA, negative for p53 and chromogranin A and showed a Ki-67 labeling index of <10%. Marked overexpression of the p53 protein as well as its high proliferative index are strong arguments in favor of the dysplastic nature of this lesion. However, further studies are required to elucidate its true clinical significance and to determine whether or not its association with a porcelain gallbladder, as noted herein, is entirely fortuitous. However, such studies can only be performed with an increased recognition by practitioners of this distinctive variant.

Correlation of DNA damage in epidemic dropsy patients to carcinogenic potential of argemone oil and isolated sanguinarine alkaloid in mice

In recent times, a higher incidence of gall bladder carcinoma in the Indo-Gangetic basin has been linked with the consumption of contaminated mustard oil. Consumption of mustard oil contaminated with argemone oil (AO) is well known to cause clinical manifestation referred to as "epidemic dropsy." Because sanguinarine, an active alkaloid of AO, has been shown to intercalate DNA, a possible correlation of DNA damage in epidemic dropsy patients to tumorigenic potential of AO and isolated sanguinarine alkaloid in mice was investigated in the present study. Single topical application of AO (0.15-0.3 ml) or isolated sanguinarine (4.5-18 micromol) followed by twice-weekly application of tetradecanoylphorbolmyristate acetate (TPA) for 25 weeks resulted in formation of tumors. Histopathologically these tumors were of squamous cell carcinoma type and similar to those found in the positive control group using dimethylbenzanthracene (DMBA)/TPA. The activities of cutaneous gamma-glutamyl transpeptidase (GGT) and glutathione-S-transferase P (GST-P), marker enzymes of tumorigenesis, were found to exhibit higher expression in AO or isolated sanguinarine/TPA treated groups when compared to control. The higher expression of p53 and p21/WAF1 in skin after single topical application of AO or isolated sanguinarine further confirms the tumorigenic response. Single topical application of AO or isolated sanguinarine alkaloid to mice showed significant DNA damage in terms of Olive tail moment (89-129%), tail length (54%) and tail DNA (153-205%) using Comet assay in skin cells. Further, the extent of DNA damage in blood cells of epidemic dropsy patients in alkaline Comet assay was found to be significantly higher as compared to normal population, indicating the genotoxic response of AO exposure. Although the genotoxic lesions may be repaired to some extent on withdrawal of consumption of AO contaminated mustard oil and the residual genotoxic effects caused by AO may not be expressed as signs of carcinogenesis. Environmental factors or hormonal changes during aging process may lead to stimulate/promote the genetically altered latent cells to form neoplastic lesions and can act as one of the etiological factors responsible for higher incidence of gall bladder carcinoma in the population of Indo-Gangetic basin.

K-ras, p53 mutations, and microsatellite instability (MSI) in gallbladder cancer

Despite the considerable progress in understanding the molecular pathology of carcinogenesis, the genetic mechanisms underlying the development and progression of gallbladder cancer (GC) are poorly understood. The survival of GC patients is generally poor. Therefore, it is very useful to define valuable prognostic factors. The most extensively studied oncogenes in gallbladder carcinogenesis are ras, commonly mutated in neoplasms of the gastrointestinal tract. K-ras oncogene is altered in a subset of gallbladder patients and mainly in those having anomalous junction of the pancreaticobiliary tract. Most of the studies of genetic abnormalities in GC have focused on p53 gene. p53 mutation/overexpression and/or LOH is present in more than 50% of gallbladder carcinomas, suggesting an important role in their pathogenesis. However, these results have not any predictive value yet. Moreover, the involvement of an alternative molecular pathway, that of microsatellite instability (MSI), is found in a limited group of GC patients. Additional research is necessary to establish its possible relation to defects of the mismatch repair (MMR) system and its proposed prognostic significance. Further elucidation of the molecular events specific to GC will help to identify novel molecular targets for the diagnosis and clinical management of the patients.

Biliary tract malignancy and chronic inflammation from the perspective of pancreaticobiliary maljunction

This is a brief review of pancreaticobiliary maljunction. The basic treatment for this condition includes either cholecystectomy or extrahepatic bile duct resection. When the condition is accompanied by malignancies, a radical operation should be the first treatment option. Knowledge on molecular pathogenesis is gradually increasing. However, studies should be expanded to include larger patient cohorts, and other types of molecules should be carefully investigated and analyzed.

Carcinoma in situ of the cystic duct

Cholelithiasis and cholesterolosis associated with carcinoma in situ of the cystic duct epithelium was observed in a male patient. Ultrastructurally, small acini-like lined a thickened, reduplicated basal lamina encompassing a pleiomorphic population of cells, including typical cholecystocytes, a poorly differentiated type, and cells containing modified mucous vesicles with heterogeneous fatty deposits. Even though the etiology of this apparent neoplastic epithelium and of its thickened basal lamina is unclear, it is hypothesized to be the result of an altered control of cell adhesion mechanisms, resulting from a repeated renewal of the typical epithelium abraded by the passage of the stones and the biliary sludge, associated with inflammatory stimuli that accompany cholecystolithiasis. Based on recent studies, it is suggested that investigations of molecular markers in extrahepatobiliary tract lesions and retrospective studies of these archival tissues could clarify the association of these neoplastic changes with other hepato-biliary lesions.

Prediction of prognosis in gallbladder carcinoma by mucin and p53 immunohistochemistry

Mucin core proteins are known to be present in various organs and are specifically expressed with carcinogenesis and closely associated with the prognoses of various malignant tumors in the digestive tract such as colorectal cancer. The present study evaluated correlations between mucin and p53 expression and prognosis of gallbladder cancer using surgically resected tissue specimens from 26 patients with gallbladder carcinoma surgically treated at our hospital. Immunohistochemical staining was performed using MUC 1, MUC2, and p53 monoclonal antibody. The level of antigen expression in the lesion was classified into four stages: none(-), slight(+), moderate (++), and severe (+ + +). According to the UICC classification, histopathological grading, levels of T, N, and M factors, and tumor stages were compared with regard to the correlations with mucin and p53 expression. All cases were classified into two groups according to the results of mucin immunohistochemistry: group A (MUC1, > or = ++; and MUC2, < or = +) and group B (MUC1, < ++; or MUC2, > +). Postoperative survival periods were compared between the two groups and p53-positive and -negative groups. Neither histological grading nor T factor correlated with mucin or p53 expression, respectively. Moreover, neither N factor nor M factor correlated with mucin or p53 expression. Furthermore, stage grouping did not correlate with mucin or p53 expression. However, when the correlation between the postoperative survival period and mucin expression was evaluated, the mean postoperative surgical period was significantly shorter in Group A than in Group B (1.02 years in Group A vs 2.92 years in Group B; P = 0.016). There was no relationship between postoperative survival period and p53 positivity. Mucin expression was independent of various tumor growth factors and clearly reflected the prognosis of gallbladder cancer. Because the relative malignancy of gallbladder cancer could be evaluated by examining the level of glycoprotein expression in tumor tissue, mucin could be a more important marker than p53 for predicting prognosis in gallbladder carcinoma using surgically resected tissue specimens.

Severe dysplasia of the gallbladder associated with occult pancreatobiliary reflux

Pancreatobiliary reflux usually occurs in patients with pancreaticobiliary maljunction and can be associated with the occurrence of gallbladder carcinoma. We present the case of a patient with pancreatobiliary reflux despite having a normal pancreatobiliary junction (occult pancreatobiliary reflux; OPBR), in whom the resected gallbladder presented severe dysplasia. The patient, a 61-year-old woman, showed thickness of the gallbladder wall, detected by ultrasonography and computed temography (CT). Her biliary amylase level in the common bile duct was 103,000 IU/l, and in the gallbladder it was 153,500 IU/l, although endoscopic retrograde cholangiopancreatography revealed a normal pancreaticobiliary junction. Immunohistochemical staining showed many p53-positive nuclei in the dysplastic lesion, and about 50% of the dysplastic cells exhibited diffuse nuclear staining for Ki-67. In the present patient, early diagnosis of occult pancreatobiliary reflux led to early detection of a precancerous lesion of the gallbladder mucosa.

Gallbladder cancer: lessons from a rare tumour

Gallbladder cancer is a relatively rare form of malignancy about which our knowledge is scant. However, a unique combination of predisposing factors - including genetic predisposition, geographic distribution, female gender bias, chronic inflammation and congenital developmental abnormalities - makes this type of cancer unique and offers potential for understanding cancer pathogenesis in general. An understanding of how these risk factors contribute to the molecular basis of the disease is essential for understanding the origins of this unusual cancer.

Immunohistochemical study of microvessel density, CD44 (standard form), p53 protein and c-erbB2 in gallbladder carcinoma

BACKGROUND

The purpose of the present study was to investigate microvessel density (MVD), and the expression of CD44 adhesion molecule, p53 protein and c-erbB2 in gallbladder carcinoma, and their relation to histological grade and tumor invasiveness.

METHODS

Immunohistochemical staining with antibodies against factor VIIIRAg, CD44 standard form (CD44s), p53 protein and c-erbB2 was performed on paraffin sections from 33 cases of gallbladder carcinoma.

RESULTS

Significant increase of MVD with increasing depth of invasion (P < 0.02) was observed. No association of MVD with histological differentiation, CD44s, p53 and c-erbB2 protein expression was found. The expression of p53 protein was significantly higher in deeply invasive tumors (P = 0.028) and in moderately and poorly differentiated carcinomas (P < 0.05). The CD44s expression was higher in well-differentiated carcinomas (P < 0.05). c-erbB2 expression was found in 30.4% of tumors studied, but did not relate to any other parameters.

CONCLUSION

Microvessel density and p53 protein expression increase progressively with increasing tumor invasiveness in gallbladder carcinomas. Microvessel density, p53 protein, CD44s, and perhaps c-erbB2 expression may be implicated in gallbladder carcinoma evolution.

In Situ and Invasive Adenocarcinomas of the Gallbladder Extending Into or Arising From Rokitansky-Aschoff Sinuses

We report 49 cases of gallbladder carcinomas that extended into or originated from Rokitansky-Aschoff sinuses (RAS), all of which were resected by laparoscopic cholecystectomy. Twenty-one tumors were in situ carcinomas that extended along RAS; six in situ carcinomas arose in adenomyomatous hyperplasia and 22 were invasive adenocarcinomas with extension into RAS. Thirty-seven patients were women and 12 men. Forty patients had cholelithiasis. The age of the patients ranged from 55 to 84 years (mean 67 years). All in situ carcinomas were incidental microscopic findings in gallbladders removed for cholelithiasis and/or cholecystitis. No patient with in situ carcinoma died as a result of the tumor, including two with in situ carcinoma that originated in adenomyomatous hyperplasia and showed microinvasion. In contrast, of 15 patients with invasive well to moderately differentiated adenocarcinoma extending into RAS and invading the muscle layer or subserosal connective tissue, 8 died 2 to 4 years after surgery. Seven patients survived 1 to 8 years after cholecystectomy. Useful clues to separate RAS with in situ carcinoma from tubular neoplastic invasive glands were the following: connection of the epithelial invaginations to the surface epithelium, recognition of normal biliary epithelium admixed with neoplastic epithelium, presence of inspissated bile in long dilated spaces, and lack of invasion to the smooth muscle bundles. In situ carcinoma spreading along RAS consisted of long tubular often dilated structures extending through the intermuscular connective tissue, whereas neoplastic glands were usually small or of medium size that invaded smooth muscle bundles or intermuscular connective tissue. Perineural invasion was seen only in invasive glands located in the subserosal connective tissue. Two cases of in situ carcinoma that arose in adenomyomatous hyperplasia and three invasive adenocarcinomas that were composed predominantly of tall columnar mucin containing cells similar to gastric foveolar cells with varying degrees of atypia and cells with biliary phenotype bear some resemblance to intraductal papillary mucinous carcinoma of the pancreas or to mucinous cystic pancreatic neoplasm. Metaplastic pyloric glands often seen in the muscle layer and subserosal connective tissue maintain their lobular pattern and should not be confused with invasive glands. Our findings indicate that distinction of in situ carcinoma spreading into RAS from tubular neoplastic glands of invasive adenocarcinomas is crucial to determine prognosis in this group of patients with gallbladder carcinoma.

Gallbladder carcinoma: the role of p53 protein overexpression and Ki-67 antigen expression as prognostic markers

BACKGROUND

The overexpression of p53 protein and the expression of Ki-67 antigen may affect the survival of patients with gallbladder carcinoma. This association has been tested in a series of 41 patients with relatively early carcinoma of the gallbladder.

METHODS

Forty-one surgical specimens from patients with a postoperative histological diagnosis of gallbladder carcinoma were studied. All patients were operated by simple cholecystectomy only because the tumours were not advanced and/or their general condition was poor. Patients submitted to radical operations were excluded. p53 expression was calculated from nuclear staining according to the intensity and extent of positive cells, as graded on a scale from 1 to 3; a combined score of >3 was considered as overexpression. Ki-67 expression was calculated by the MIB-I index: the percentage of positively stained tumour cell nuclei out of the total tumour cells counted (n = 1000); >20% of stained cells was considered positive.

RESULTS

Twenty-nine gallbladder carcinomas (71%) overexpressed p53 protein in the cell nuclei. No significant differences were found in relation to cell differentiation on the level of tumour infiltration through the gallbladder wall. Five-year survival of patients with gallbladder carcinoma overexpressing p53 was 17.2%, while survival of patients without p53 overexpression was 30% (not significant). Twenty-four cases (58.5%) were considered positive for the MIB-I index. There were no differences between the grade of cell differentiation and wall infiltration. Five-year survival of the patients with a MIB-I positive index was 9.2% as opposed to 27.7% for those with a negative index (not significant).

CONCLUSIONS

p53 protein nuclear overexpression and Ki-67 protein expression in gallbladder carcinoma were not related to histological differentiation, level of gallbladder wall invasion or patient survival.