Molecular Targets and Emerging Therapies for Advanced Gallbladder Cancer

Expression Pattern of Estrogen Receptor Alpha and Progesterone Receptor in Gallbladder Carcinoma and Their Association with Clinicopathological Parameters and Overall Survival

BACKGROUND

Gallbladder cancer (GBC) is a highly aggressive malignant tumor with a poor prognosis. Despite being first described two centuries ago, there are no targeted therapies available beyond conventional cytotoxic therapy. Epidemiological studies have shown that the incidence of gallbladder cancer is higher in females than males. This suggests that the gallbladder may be a female sex hormone-responsive organ, and these hormones might be involved in the pathogenesis of gallbladder cancer. Therefore, we aimed to analyze the expression of ERα and PR in GBC and correlate their expression with clinicopathological variables and overall survival.

PATIENTS AND METHODS

A total of 235 histopathologically diagnosed GBC cases were included in this hospital-based cross-sectional study. Clinicopathological data were collected, and the expression of ERα and PR was evaluated by immunohistochemistry.

RESULTS

The mean age of this study population was 55.47 ± 8.45 with range 28-87 years. Females were predominated over male with a male-to-female ratio of 1:3.5. Positive nuclear expression of the ERα and PR was found in 13 (5.5%) and eight (3.4%) cases, respectively. Apart from nuclear staining, cytoplasmic expression of ERα and PR was found in three (1.2%) and 31 (13.2%) cases, respectively. Higher percentage of positive nuclear expression of ER was found in < 50 years age (p value = 0.04), parity > 4 (p value = 0.02), advanced pT stage (T3) (p value = 0.01), lymphovascular invasion (p value = 0.02), and liver invasion (p value = 0.04) which were statistically significant. Higher percentage of PR expression was also observed in < 50 years age (p value = 0.01), and tumor associated with gallstone (p value = 0.04). There was no significant correlation between cytoplasmic expression of ER, PR, and clinicopathological variables. In multivariate analysis, there was no significant correlation between ER or PR positive expression and overall survival.

CONCLUSION

Although nuclear expression of ERα was significantly associated with progressive disease factors but the positive expression was found in very small percentage of GBC cases. So anti-hormone therapy might be an option in patient with ER α positive gallbladder carcinoma.

Diagnostic Utility of Next-Generation Sequencing in Circulating Free DNA and a Comparison With Matched Tissue in Gallbladder Carcinoma

Mutation detection for therapy monitoring in cell-free DNA (cfDNA) is used clinically for some malignancies. Gallbladder carcinoma (GBC) presents a diagnostic challenge and has limited late-stage treatment options. To our knowledge, this novel study examines, for the first time, genomic alterations in cfDNA from GBC to assess diagnostic accuracy and therapeutic options. The concordance of somatic genomic changes in cfDNA and DNA from paired tumor tissue was analyzed. Paired serum and tissue samples from 40 histologically proven GBC, 20 cholecystitis, and 4 normal (noninflamed gallbladder) controls were included. Targeted next-generation sequencing with a 22-gene panel (Colon and Lung Cancer Research Panel v2, Thermo Scientific) in cfDNA and tumor tissue with high depth and uniform coverage on ION Personal Genome Machine (ION, PGM) was performed. A spectrum of 223 mutations in cfDNA and 225 mutations in formalin-fixed paraffin-embedded tissue DNA were identified in 22 genes. Mutations ranged from 1 to 17 per case. In cfDNA frequent alterations were in TP53 (85.0%), EGFR (52.5%), MET (35%) CTNNB1, SMAD4, BRAF (32.5%), PTEN (30%), FGFR3 and PIK3CA (27.5%), NOTCH1 (25.0%), and FBXW7 and ERBB4 (22.5%). At least one clinically actionable mutation was identified in all cfDNA samples. Paired samples shared 149 of 225 genetic abnormalities (66.2%). Individual gene mutation concordance ranged from 44.44% to 82.0% and was highest for EGFR (82.0%), BRAF and NOTCH1 (80.0%), TP53 (73.08%), MET (72.22%), and ERBB4 (71.42%) with a significant level of correlation (Spearman r = 0.91, P ≤ .0001). The sensitivity and specificity of the TP53 gene at the gene level was the highest (94.44% and 100.0%, respectively). Overall survival was higher for ERBB4 and ERBB2 mutant tumors. The adenocarcinoma subtype revealed specific genetic changes in ERBB4, SMAD4, ERBB2, PTEN, KRAS, and NRAS. NGS-based cfDNA mutation profiling can be used to diagnose GBC before surgery to guide treatment decisions. Targeted therapy identified in GBC included SMAD4, ERBB2, ERBB4, EGFR, KRAS, BRAF, PIK3CA, MET, and NRAS.

Update on Chemoresistance Mechanisms to First-Line Chemotherapy for Gallbladder Cancer and Potential Reversal Strategies

OBJECTIVE

Gallbladder cancer (GBC) mortality remains high and chemoresistance is increasing. This review consolidates what is known about the mechanisms of chemoresistance to inform and accelerate the development of novel GBC-specific chemotherapies.

METHODS

Studies related to GBC-related chemoresistance were systematically screened in PubMed using the advanced search function. Search terms included GBC, chemotherapy, and signaling pathway.

RESULTS

Analysis of existing studies showed that GBC has poor sensitivity to cisplatin, gemcitabine (GEM), and 5-fluorouracil. DNA damage repair-related proteins, including CHK1, V-SCR, and H2AX, are involved in tumor adaptation to drugs. GBC-specific chemoresistance is often accompanied by changes in the apoptosis and autophagy-related molecules, BCL-2, CRT, and GBCDRlnc1. CD44 + and CD133 + GBC cells are less resistant to GEM, indicating that tumor stem cells are also involved in chemoresistance. In addition, glucose metabolism, fat synthesis, and glutathione metabolism can influence the development of drug resistance. Finally, chemosensitizers such as lovastatin, tamoxifen, chloroquine, and verapamil are able improve the therapeutic effect of cisplatin or GEM in GBC.

CONCLUSIONS

This review summarizes recent experimental and clinical studies of the molecular mechanisms of chemoresistance, including autophagy, DNA damage, tumor stem cells, mitochondrial function, and metabolism, in GBC. Information on potential chemosensitizers is also discussed. The proposed strategies to reverse chemoresistance should inform the clinical use of chemosensitizers and gene-based targeted therapy for this disease.

Single-cell RNA sequencing highlights the functional role of human endogenous retroviruses in gallbladder cancer

Background

Gallbladder cancer (GBC), the most common malignancy of the biliary tract, shows late diagnosis and low survival rate and requires continued search for new diagnostic biomarkers and therapeutic targets. Human endogenous retroviruses (HERVs) are specifically prone to be reactivated in diverse cancers and are implicated in cancer progression and immunotherapy.

Methods

Single-cell RNA sequencing was performed on tumor tissues and paired adjacent tissues from 4 GBC patients. Dual-luciferase reporter assay was applied to measure enhancer activity of HERV sequences.

Findings

We dissected the cellular diversity and described the HERV transcriptomic landscape for GBC. We found that HERVs were transcribed in a cell type-specific manner and different HERV families were associated with diverse biological effects. HERVs could function as enhancers, presumably causing altered expression of neighboring genes. The transcription level of HERVH was gradually elevated with the malignant transformation of epithelial cells, suggesting HERVH may be a potential early diagnostic biomarker of GBC. HHLA2, a newly emerging immune checkpoint, was derived by HERVH, exhibited an expressional correlation with HERVH, and was identified as a promising target for immunotherapy.

Interpretation

Exploring the transcriptional landscape and potential functional impact of HERVs highlights the important role of HERVs in GBC and provides a fresh perspective on managing GBC.

Funding

This study was supported by the National Natural Science Foundation of China (31970176, 81972256) and the research grants from the Innovation Capacity Building Project of Jiangsu province (BM2020019).

Progress in gallbladder cancer with lymph node metastasis

Gallbladder cancer (GBC) is a malignant tumor that originates from the mucosal lining of the gallbladder. It is distinctly regional and is common in certain geographic regions of developing countries. GBC has a high degree of insidiousness as well as a high propensity for metastatic spread, resulting in the majority of patients being diagnosed at an advanced stage. Lymph node metastasis (LNM) is fairly common in GBC patients and is an independent risk factor for a poor prognosis. This article is focused on the lymph node pathways and metastatic directions of GBC. Furthermore, it summarizes the different lymph node groupings, disease stages and treatments. In the future, it is of great significance to develop individualized treatment and predict the outcomes of GBC patients with different lymph node conditions.

Trends in Primary Gallbladder Cancer Incidence and Incidence-based Mortality in the United States, 1973 to 2015

OBJECTIVES

Primary gallbladder cancer (GBC) is the most common biliary tract cancer with poor survival despite aggressive treatment. This study aimed to investigate the trends of GBC incidence and incidence-based mortality (IBM) over the last 4 decades.

MATERIALS AND METHODS

GBC cases diagnosed between 1973 and 2015 were retrieved from the Surveillance, Epidemiology, and End Results (SEER) database. Incidence rates, IBM rates, and annual percent changes (APCs) were calculated and stratified according to population and tumor characteristics.

RESULTS

The cohort consisted of 10,792 predominantly white (81%) and female (71%) GBC patients. The overall GBC incidence decreased by 1.65% (95% confidence interval [CI]: 1.45% to 1.84%) per year since 1973, but has plateaued since 2002. IBM decreased by 1.69% (95% CI: 1.22% to 2.16%) per year from 1980 to 2015; the rate of decrease in IBM rates was lower during 1997 to 2015 (APC: -1.19%, 95% CI: -1.68% to -0.71%) compared with 1980 to 1997 (APC: -3.13%, 95% CI: -3.68% to -2.58%).

CONCLUSIONS

The incidence and IBM rates of GBC have been decreasing over the last 40 years, but the decrease plateaued over the last 2 decades. The effects of treatment modalities, including laparoscopic cholecystectomy, adjuvant chemotherapy, and radiation on the incidence and IBM of GBC need to be further investigated.

MiR-4733-5p promotes gallbladder carcinoma progression via directly targeting kruppel like factor 7

Gallbladder carcinoma (GBC) is highly aggressive with poor prognosis. Accumulating reports show that miRNAs play critical roles in tumor progression. Previous studies have identified several miRNAs that promoted or inhibited GBC cell proliferation and/or metastasis. Here, we used the Gene Expression Omnibus (GEO) dataset to identify dysregulated miRNAs in GBC, followed by validating the upregulation of the miR-4733-5p and downregulation of kruppel-like factor 7 (KLF7) in GBC biopsies by quantitative real-time PCR (RT-qPCR), in situ hybridization (ISH) staining, and immunohistochemistry (IHC) assays. GBC cell proliferation and invasion capacities mediated by miR-4733-5p were evaluated by a series of function assays in vitro, including CCK-8, colony formation assay, wound healing assay and transwell assay. Xenograft tumor model found that miR-4733-5p promoted GBC tumor growth in vivo. This study clarified that miR-4733-5p was upregulated in GBC and promoted GBC cell proliferation via directly binding to 3' untranslated region (UTR) of KLF, which was downregulated and prohibited the proliferation and migration of GBC cells.

Treatment of Resectable Gallbladder Cancer

Gallbladder cancer (GBC) is the most common biliary tract cancer worldwide and its incidence has significant geographic variation. A unique combination of predisposing factors includes genetic predisposition, geographic distribution, female gender, chronic inflammation, and congenital developmental abnormalities. Today, incidental GBC is the most common presentation of resectable gallbladder cancer, and surgery (minimally invasive or open) remains the only curative treatment available. Encouragingly, there is an important emerging role for systemic treatment for patients who have R1 resection or present with stage III-IV. In this article, we describe the pathogenesis, surgical and systemic treatment, and prognosis.

Precursor Lesions of Gallbladder Carcinoma: Disease Concept, Pathology, and Genetics

Understanding the pathogenesis and carcinogenesis of gallbladder adenocarcinoma is important. The fifth edition of the World Health Organization’s tumor classification of the digestive system indicates three types of preinvasive neoplasm of the gallbladder: pyloric gland adenoma (PGA), biliary intraepithelial neoplasia (BilIN), and intracholecystic papillary neoplasm (ICPN). New terminologies have also been introduced, such as intracholecystic papillary-tubular neoplasm, gastric pyloric, simple mucinous type, and intracholecystic tubular non-mucinous neoplasm (ICTN). Pancreatobiliary maljunction (PBM) poses a markedly high risk for bile duct carcinoma, which was analyzed and investigated mainly by Asian researchers in the past; however, recent studies have clarified a similar significance of biliary carcinogenesis in Western countries as well. In this study, we reviewed and summarized information on three gallbladder neoplastic precursors, PGA, BilIN, and ICPN, and gallbladder lesions in patients with PBM.