The oncogenic role of NF1 in gallbladder cancer through regulation of YAP1 stability by direct interaction with YAP1

BACKGROUND

Gallbladder cancer (GBC) is the most prevalent and invasive biliary tract malignancy. As a GTPase-activating protein, Neurofibromin 1 (NF1) is a tumor suppressor that negatively regulates the RAS signaling pathway, and its abnormality leads to neurofibromatosis type 1 (NF-1) disease. However, the role of NF1 playing in GBC and the underlying molecular mechanism has not been defined yet.

METHODS

A combination of NOZ and EH-GB1 cell lines as well as nude mice, were utilized in this study. mRNA expression and protein levels of NF1 and YAP1 were evaluated by quantitative real-time PCR (qRT-PCR), western blot (WB), and immunohistochemistry (IHC). In vitro and in vivo assays were performed to explore the biological effects of NF1 in NOZ and EH-GB1 cells via siRNA or lv-shRNA mediated knockdown. Direct interaction between NF1 and YAP1 was detected by confocal microscopy and co-immunoprecipitation (Co-IP), and further confirmed by GST pull-down assay and isothermal titration calorimetry assay (ITC). The stability of proteins was measured by western blot (WB) in the presence of cycloheximide.

RESULTS

This study showed that a higher level of NF1 and YAP1 was found in GBC samples than in normal tissues and associated with worse prognoses. The NF1 knockdown impaired the proliferation and migration of NOZ in vivo and in vitro by downregulating YAP1 expression. Moreover, NF1 co-localized with YAP1 in NOZ and EH-GB1 cells, and the WW domains of YAP1 specifically recognized the PPQY motif of NF1. The structural modeling also indicated the hydrophobic interactions between YAP1 and NF1. On the other hand, YAP1 knockdown also impaired the proliferation of NOZ in vitro, phenocopying the effects of NF1 knockdown. Overexpression of YAP1 can partially rescue the impaired proliferation in NF1 stably knockdown cells. In mechanism, NF1 interacted with YAP1 and increased the stability of YAP1 by preventing ubiquitination.

CONCLUSIONS

Our findings discovered a novel oncogenic function of NF1 by directly interacting with YAP1 protein and stabilizing YAP1 to protect it from proteasome degradation in NOZ cells. NF1 may serve as a potential therapeutic target in GBC.

YKL-40 derived from infiltrating macrophages cooperates with GDF15 to establish an immune suppressive microenvironment in gallbladder cancer

Despite of the high lethality of gallbladder cancer (GBC), little is known regarding molecular regulation of the tumor immunosuppressive microenvironment. Here, we determined tumor expression levels of YKL-40 and the molecular mechanisms by which YKL-40 regulates escape of anti-tumor immune surveillance. We found that elevated expression levels of YKL-40 in plasma and tissue were correlated with tumor size, stage IV and lymph node metastasis. Single cell transcriptome analysis revealed that YKL-40 was predominantly derived from M2-like subtype of infiltrating macrophages. Blockade of M2-like macrophage differentiation of THP-1 cells with YKL-40 shRNA resulted in reprogramming to M1-like macrophages and restricting tumor development. YKL-40 induced tumor cell expression and secretion of growth differentiation factor 15 (GDF15), thus coordinating to promote PD-L1 expression mediated by PI3K, AKT and/or Erk activation. Interestingly, extracellular GDF15 inhibited intracellular expression of GDF15 that suppressed PD-L1 expression. Thus, YKL-40 disrupted the balance of pro- and anti-PD-L1 regulation to enhance expression of PD-L1 and inhibition of T cell cytotoxicity, leading to tumor immune evasion. The data suggest that YKL-40 and GDF15 could serve as diagnostic biomarkers and immunotherapeutic targets for GBC.

The epidemiological trends of biliary tract cancers in the United States of America

BACKGROUND

Biliary tract cancers (BTCs) are a series of heterogeneous malignancies that are broadly grouped based on the anatomical site where they arise into subtypes including intrahepatic cholangiocarcinoma (ICC), extrahepatic cholangiocarcinoma (ECC), gallbladder cancer (GBC), and ampulla of Vater cancer (AVC).

METHODS AND RESULTS

The present study provides an overview of the epidemiology of the various BTCs based on data from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) database from 2000 to 2018. Distinct differences in both incidence and mortality rates were observed for these BTCs as a function of age, sex, ethnicity, and calendar year. In 2018, BTCs emerged as the fifth most prevalent form of alimentary tract cancer in the USA. While the incidence and mortality of ICC appear to be increasing, the incidence rates of GBC, ECC, and AVC have remained stable, as have the corresponding mortality rates. The most common and deadliest BTCs in 2018 were ICC and GBC among males and females, respectively. The ethnic groups exhibiting the highest incidence rates of these different BTCs were American Indians and Alaska Natives for GBC, and Asian and Pacific Islanders for ICC, ECC, and AVC. The incidence of all of these forms of BTC rose with age. There were some variations in BTCs in terms of staging, locoregional surgical treatments, adjuvant therapies, and prognostic outcomes from 2000 to 2018.

CONCLUSIONS

The epidemiological characteristics, staging, locoregional surgical treatments, adjuvant therapies, and prognostic outcomes were distinct for each of these BTCs.

Survival analysis and prognostic factors of the carcinoma of gallbladder

BACKGROUND

The present study aims to evaluate the survival status of patients with gallbladder cancer (GBC) and explore the prognostic factors for the improvement and preventions.

METHODS

The study consists of 176 patients with clinically diagnosed gallbladder cancer; the study was conducted between 2019 and 2021 registered at Kamala Nehru Memorial Cancer Hospital, Prayagraj, India. The survival rates were analyzed by the Kaplan-Meier method; survival rate difference was analyzed by log-rank test, prognosis factors; and hazard ratio for mortality outcomes was estimated using Cox regression method.

RESULTS

The overall median survival time of patients was 5 months with the 1-year, 2-year, and 3-year survival rates of 24.4%, 8.5%, and 4.5%, respectively. The 3-year survival for patients with jaundice was 2.9%, liver infiltration (4.2%), gallstones (0.8%), and with advanced tumor grade (1.4%). Elderly GBC patients had lower survival rates (3.8%), while the 3-year overall survival for patients residing in urban areas dropped to zero. No patients in the tumor stage (T3/T4) and with distance metastasis stage survived in 3 years, while only 1.1% of patients with advanced nodal stage survived. On receiving surgery and radiation therapy, the 3-year survival rate increased to 19.5% and 35%, respectively. The results of multivariate analysis showed that urban region (HR = 1.568, p = 0.040), gallstone or not (1.571, p = 0.049), N stage (HR = 1.468, p = 0.029), and M stage (HR = 2.289, p < 0.0001) were independent risk factors for prognosis, while surgery or not (HR = 0.573, p = 0.030) was the protective factor for the prognosis of GBC.

CONCLUSION

The overall survival of GBC in the Gangetic belt is poor. The geographical region of patients, gallstones, and N and M stage was the risk factors for prognosis, while surgery or not was the protective factor for the prognosis of GBC.

Adjuvant treatment for the elderly patient with resected gallbladder cancer: a SEER-Medicare analysis

Background

In patients with resected gallbladder cancer (GBC), the role of adjuvant chemotherapy (aCT) remains ill-defined, especially in elderly patients. This study evaluates the value of aCT in elderly patients with GBC and assesses response according to tumor stage.

Methods

Patients of ≥65 years of age with resected GBC diagnosed from 2004-2015 were identified using a Surveillance, Epidemiology and End Results (SEER)/Medicare linked database. After propensity score matching, survival of patients treated with aCT was compared to survival of patients who did not receive aCT using Kaplan-Meier and Cox proportional hazards analysis.

Results

Of 2,179 patients with resected GBC, 876 (25%) received aCT. In the full cohort of 810 propensity-score matched patients, survival did not differ between patients treated with aCT (17.6 months ) and without aCT (19.5 months, P=0.7720). Subgroup analysis showed that survival was significantly better after aCT in T3/T4 disease (12.3 vs. 7.2 months, P=0.013). Interaction analysis showed that benefit of aCT was primarily seen in combined T3/T4, node-positive disease (HR 0.612 , P=0.006).

Conclusions

In this large cohort of elderly patients with resected GBC, aCT was not associated with increased survival. However, aCT may provide a survival benefit in T3/4, node-positive disease.

Analysis of the efficacy and prognostic factors of PD-1 inhibitors in advanced gallbladder cancer

Background

Gallbladder cancer (GBC) is highly malignant, its early diagnosis is difficult, and the 5-year survival rate is less than 5%. For patients with advanced GBC (GBCa), combined chemotherapy, radiotherapy, targeted therapy, and immunotherapy are needed to improve the overall survival (OS) rate of patients.

Methods

Data were collected from 53 patients with GBCa who had volunteered to receive programmed death protein-1 (PD-1)-based treatment at the First Affiliated Hospital of Nanjing Medical University from February 2018 to February 2021. Statistical analysis of the collected data, including Kaplan-Meier method, log-rank test, Cox proportional hazard regression model and other methods.

Results

The objective response rates (ORRs) and disease control rates (DCRs) of 53 participants 3 months after receiving immunotherapy were 30.2% and 79.2%, respectively. The ORRs and DCRs of the combined treatment group were higher than those of the camrelizumab group (CG) (P<0.05). The DCRs of the camrelizumab plus apatinib group (CAG) at 3 and 6 months were 90.9% and 45.5% (P=0.003), respectively, while the DCRs at 3 and 6 months of the camrelizumab plus chemotherapy group (CCG) were 85.7% and 71.4% (P=0.450), respectively. After treatment, there were statistically significant differences before and after CA199 for each group (P<0.05). The median progression-free survival (mPFS) of the 53 participants was 7 months, and the median overall survival (mOS) was 12 months. The mPFS and mOS of the CAG and the CCG were greater than those in the CG (6 vs. 3 months, P<0.001, 12 vs. 8 months, P=0.019; 9 vs. 3 months, P<0.001, 13 vs. 8 months, P<0.001, respectively). A total of 16 cases had grade 1 or 2 adverse events, and 3 cases had grade 3 and higher adverse events.

Conclusions

For GBCa patients, PD-1 combined with targeted therapy or chemotherapy is more effective than immunotherapy alone. The targeted therapy group has more obvious early effects on the disease control rate, and combined chemotherapy can achieve sustained effects, providing new ideas for the future GBCa application of immune, targeted, and chemotherapy sequential therapy.

Modified FOLFIRINOX for unresectable locally advanced or metastatic gallbladder cancer, a comparison with GEMOX regimen

Background

The first-line chemotherapy regimen for advanced gallbladder cancer (GBC) is gemcitabine plus platinum (GP), despite its efficacy is limited. The current investigation is a retrospective study to compare the safety and efficacy between the modified FOLFIRINOX (mFOLFIRINOX) and gemcitabine plus oxaliplatin (GEMOX) as the first-line chemotherapy for unresectable locally advanced or metastatic GBC.

Methods

The data of patients with unresectable locally advanced or metastatic GBC, who were treated with mFOLFIRINOX or GEMOX as the first-line therapy between April 2014 and April 2018 at Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, were retrieved. This retrospective study evaluated the clinical characteristics, survival outcomes and adverse events.

Results

A total of 44 patients (n=25 in mFOLFIRINOX, n=19 in GEMOX) were included. There were no significant differences between groups in baseline characteristics. The median progression free survival (mPFS) was 5.0 months in the mFOLFIRINOX group and 2.5 months in the GEMOX group [P=0.021; hazard ratio (HR), 0.499; 95% CI, 0.266 to 0.937]. The median overall survival (mOS) was 9.5 months in the mFOLFIRINOX group and 7.0 months in the GEMOX group (P=0.019; HR, 0.471; 95% CI, 0.239 to 0.929). Disease control rate (DCR) was 76.0% in the mFOLFIRINOX group and 47.4% in the GEMOX group (P=0.051). The rate of grade 3-4 adverse events was 48% in the mFOLFIRINOX group and 36.8% in the GEMOX group (P=0.459). The incidence of grade 3-4 neutropenia and diarrhea were more common in the mFOLFIRINOX group, while the incidence of grade 3-4 thrombocytopenia and peripheral neuropathy were more common in the GEMOX group.

Conclusions

mFOLFIRINOX might improve the poor prognosis of unresectable locally advanced or metastatic GBC, and the results need to be further verified by prospective clinical studies.

Single-cell RNA-seq reveals transcriptional landscape and intratumor heterogenicity in gallbladder cancer liver metastasis microenvironment

Background

Gallbladder cancer (GBC) is a highly aggressive biliary epithelial malignancy. The median survival time of GBC patients was less than 1 year. Tumor invasion and metastasis are the major cause of high mortality of GBC patients. However, the molecular mechanisms involved in GBC metastases are still unclear.

Methods

We performed 10X genomics single-cell RNA sequencing (scRNA-seq) on GBC liver metastasis tissue to evaluate the characteristics of the GBC liver metastasis microenvironment.

Results

In this study, 8 cell types, a total of 7,788 cells, including T cells, B cells, malignant cells, fibroblasts, endothelial cells, macrophages, dendritic cells (DCs), and mast cells were identified. Malignant cells displayed a high degree of intratumor heterogenicity, while neutrophils were found to promote GBC cell proliferation, migration, and invasion. Furthermore, cytotoxic cluster of differentiation (CD8⁺) T cells became exhausted and CD4⁺ regulatory T cells (Tregs) exhibited immunosuppressive characteristics. Macrophages played an important role in the tumor microenvironment (TME). We identified three distinct macrophage subsets and emergent M2 polarization. We also found that cancer-associated fibroblasts exhibited heterogeneity and may be associated with GBC metastasis.

Conclusions

Although preliminary in nature, our study provides a landscape view at the single-cell level. These results offer a unique perspective into understanding the liver metastasis of GBC.

Gallbladder cancer: epidemiology and genetic risk associations

Gallbladder cancer (GBC) is a form of hepatobiliary malignancy that develops from the mucosal lining of the gallbladder. The early development of gallbladder cancer is usually asymptomatic and gallbladder cancer has a high propensity to metastatic dissemination, thus most patients are diagnosed at intermediate to advanced stages for which there is no curative treatment. Consequently, gallbladder cancer is highly lethal. Though the overall global incidence of gallbladder cancer is low, there is marked geographic variation and ethnic communities in Asia as well as Native American populations in both North and South America are affected disproportionately. This article provides a comprehensive overview of the current epidemiology and risk and protective factors associated with gallbladder cancer development. In addition, the current knowledge on environmental and genetic risk associations for gallbladder cancer and the need for additional large-scale genome wide association studies (GWAS) are discussed.

A new nomogram from the SEER database for predicting the prognosis of gallbladder cancer patients after surgery

Background

To study the prognostic significance in gallbladder cancer (GBC) patients of the four N stage methods of log odds of positive lymph nodes (LODDS), lymph node ratio (LNR), and N stage in the 7th and 8^th editions of the American Joint Committee on Cancer (AJCC), and to establish a prognostic model of GBC based on LODDS.

Methods

Data of 1,321 patients with GBC who underwent surgical resection of lymph nodes from 2010 to 2014 were collected from the Surveillance, Epidemiology, and End Results (SEER) database. We then randomly divided these data into a training set (n=925) and a validation set (n=396). C-index, Akaike information criterion (AIC), and area under the curve (AUC) were calculated to evaluate the accuracy of LODDS, LNR, and N stage in the 7^th and 8^th editions of the AJCC. Cox multivariate analysis was performed to determine whether LODDS was an independent prognostic factor, and a nomogram model was established. C-index was used to evaluate the accuracy of the nomogram. A receiver operating characteristic (ROC) curve was drawn and the area under the AUC was calculated to evaluate the accuracy of the nomogram in predicting patients' 1-, 3-, and 5-year overall survival (OS).

Results

Univariate analysis showed that the four methods were all correlated with OS. Through C-index, AIC and AUC, We found that LODDS had the best accuracy of the four methods. C-index and AUC analysis revealed that the nomogram based on LODDS had excellent prognostic ability. All the results were verified in the validation set.

Conclusions

LODDS is an independent prognostic factor for GBC patients, and it is the best N stage in the SEER database. This new nomogram-containing LODDS system is a great model to predict the prognosis of GBC patients.

Somatic genetic aberrations in gallbladder cancer: comparison between Chinese and US patients

Background

Gallbladder cancer (GBC) is often diagnosed at an advanced stage with limited therapeutic options and poor prognosis. The five-year survival rate of this cancer when diagnosed at an advanced stage is below 5%, and the median survival time is less than a year with standard gemcitabine-based chemotherapy. Survival benefit with second-line treatment is unknown. Thus, there is an urgent need for novel treatment strategies and targeted therapy based on next generation sequencing (NGS) may be of value.

Methods

Comprehensive genomic profiling (CGP) was performed with NGS panel on paraffin-embedded tumors from a cohort of 108 Chinese and 107 US GBC patients. Clinical data were collected using an IRB approved protocol from a single-center in US and from China.

Results

In Chinese and US GBC cohorts, an average of 6.4 vs. 3.8 genomic alterations (GAs) were identified per patient. The most frequent alterations were TP53 (69.4%), CDKN2A/B (26%), ERBB2 (18.5%), PIK3CA (17%) and CCNE1 (13%) in Chinese cohort, TP53 (57.9%), CDKN2A/B (25%), SMAD4 (17%), ARID1A (14%), PIK3CA (14%) and ERBB2 (13.1%) in US patients. NFE2L2 mutations were present in 6.5% of Chinese patients and not observed in the US cohort. Interestingly, ERBB2 genetic aberrations were significantly associated with better pathological tumor differentiation and tended to co-occurrence with CDKN2A/B mutations in both the Chinese and US GBC cases. Out of the top 9 dysregulated genetic pathways in cancer, Chinese patients harbored more frequent mutations in ERBB genes (30.6% vs. 19.0%, P=0.04). High frequency of PI3K/mTOR pathway variations was observed in both Chinese (37%) and US cohort (33%) (P=0.5). Additionally, both Chinese and US GBC patients exhibited a relatively high tumor mutational burden (TMB) (17.6% and 17.0%, respectively). In the Chinese cohort, a significant association was seen between direct repair gene alterations and TMB ≥10 muts/Mb (P=0.004).

Conclusions

In our study, over 83% Chinese and 68% US GBC patients had actionable alterations that could potentially guide and influence personalized treatment options. The identification of high TMB, ERBB2, CDKN2A/B, PI3K/mTOR pathway and DNA repair mutations indicated that both Chinese and US GBC patients may benefit from targeted or immune checkpoint inhibitors.

Development and validation of a nomogram for survival benefit of lymphadenectomy in resected gallbladder cancer

Background

Due to absence of large, prospective, randomized, clinical trial data, the potential survival benefit of lymphadenectomy with different number of regional lymph nodes (LNs) remains controversial. We aim to create a predicting model to help estimate individualized potential survival benefit of lymphadenectomy with more regional LNs for patients with resected gallbladder cancer (GBC).

Methods

Patients with resected GBC were selected from the Surveillance, Epidemiology, and End Results database who were diagnosed between 2004 and 2014. Covariates included age, race, sex, grade, histological stage, tumor sizes and receipt of non-primary surgery. Two types of multivariate survival regression models were constructed and compared. The best model performance was tested by the external validation data from our hospital.

Results

A total of 1,669 patients met the inclusion criteria for this study. The lognormal survival model showed the best performance and was tested by the external validation data, including 193 patients with resected GBC from our hospital. Nomograms, which based on the accelerated failure time parametric survival model, were built to estimate individualized survival. C-index, was up to 0.754 and 0.710 in internal validation for more and less regional LNs removed, respectively. Both of internal and external calibration curves showed good agreement between predicted and observed outcomes in the 1-, 3-, and 5-year overall survival (OS).

Conclusions

A predicting model can be used as a decision model to predict which patients may obtain benefit from lymphadenectomy with more regional LNs.

Biliary tract cancer prognostic and predictive genomics

Biliary tract cancer (BTC) is comprised of intrahepatic cholangiocarcinoma (ICC), extrahepatic cholangiocarcinoma (EHC) and gallbladder cancer (GBC). These tumors arise in the biliary epithelium, share histological characteristics and are associated with grim prognosis even when diagnosed at early stages. Moreover, its relatively low incidence in developed countries has precluded the development of clinical trials addressing specific differences among BTC subgroups in terms of their biology, treatment response and clinical outcomes. In this scenario, the development of effective treatment strategies for patients has been rather modest. To date, the combination of cisplatin plus gemcitabine remains as the standard first line therapy in advanced disease and after progression to this regimen there are limited treatment options. Next generation sequencing (NGS) studies have assessed the distribution of driver genes and potentially actionable genomic alterations among ICC, EHC and GBC. Here, we outline genomic differences among these subsets and describe key milestones in order to develop novel targeted drugs against BTCs. Although the early results of several studies are promising, international collaboration is critical to conduct adequately-powered trials, enrolling patients from high-incidence countries.

Concurrent chemoradiation for resected gall bladder cancers and cholangiocarcinomas

Background

Gallbladder cancer (GBC) and cholangiocarcinoma (CCA) are rare entities with relatively poor prognoses. We compared treatment outcomes of definitive resection with or without neoadjuvant therapy in GBC and CCA patients.

Methods

All non-metastatic GBC and CCA patients at a single institution who underwent definitive resection from 1992-2016 were analyzed. We compared overall survival (OS), locoregional failure (LRF) and distant failure (DF) in patients who received neoadjuvant therapy (chemotherapy and/or radiation) versus those who did not receive neoadjuvant treatment. OS was analyzed using the Kaplan-Meier method and log rank tests. Cox proportional hazard models were used to analyze time to recurrence.

Results

Out of 128 patients, 90 had GBC and 38 had CCA, 25 patients (27%) among GBC and 8 patients (21%) with CCA were T3, T4 or node positive. Overall, 52 (40%) GBC and 25 (20%) CCA patients received neoadjuvant treatment, chemotherapy alone 60 patients (47%) or radiation with or without chemotherapy 17 patients (13%). Chemotherapy was single agent in 44 patients (34%) and multi-agent in 25 (20%). The median OS for GBC patients was 3.1 years with 2.6 years for no neoadjuvant group and 3.1 years for neoadjuvant group (P=0.6786). Median OS was 2.6 years for CCA patients, 3.6 years for no neoadjuvant therapy versus 2.0 years for neoadjuvant group (P=0.1613). There was a trend towards increased DF in patients with CCA and GBC receiving neoadjuvant therapy: HR 2.74, 95% CI, 0.73-10.3, P=0.14 and 0.92, 95% CI, 0.44-1.93, P=0.82 respectively. The hazard ratio for time to LRF in CCA patients receiving neoadjuvant treatment was 3.17, 95% CI, 0.62-16.31, P=0.16 whereas HR was 0.15, 95% CI, 0.10-1.76, P=0.23 for GBC patients. Among GBC patients, the pattern of first failure was locoregional in 8 (10%) having 3 LRF in neoadjuvant group (2 with chemotherapy, 1 with CRT, 0 with RT alone) as compared to 5 in adjuvant group. Among 28 (35%) patients with DF first, 15 patients received neoadjuvant therapy versus 13 patients in non-neoadjuvant group. In CCA patients, LRF occurred first in 6 patients receiving neoadjuvant treatment (3 with chemotherapy, 1 with CRT, 2 with RT alone) as compared to 2 patients who were treated with non-neoadjuvant CRT. DF was the first site of failure in 9 patients treated with neoadjuvant CRT (8 with chemotherapy, 0 with CRT and 1 with RT alone) as compared to 4 patients without neoadjuvant treatment.

Conclusions

In this retrospective data set, a trend towards better survival was seen in adjuvantly treated CCA patients, but not in GBC patients. Recurrence patterns also appear different among the two, which might be attributed to treatment modality used, patient selection or unmeasured factors.

Keywords

Gallbladder cancer (GBC); cholangiocarcinoma (CCA); neoadjuvant; resection; chemoradiation; chemotherapy.

Organ-specific concept and controversy for premalignant lesions and carcinogenesis of gallbladder cancer

An analysis of premalignant lesions, risk factors and models of carcinogenesis of gallbladder cancer (GBC) involves the concept of organ specificity. In GBC, the dysplasia-carcinoma sequence and metaplasia-dysplasia-carcinoma sequence are considered to be more important models of carcinogenesis than the adenoma-carcinoma sequence. Cholecystectomy is recommended for gallbladder polyps ≥1.0 cm, and all pre-invasive adenomas and papillary neoplasms ≥1.0 cm are defined as intracholecystic papillary-tubular neoplasms (ICPTNs). Although adenomyomatosis (ADM) and xanthogranulomatous cholecystitis (XGC) are controversial lesions, a knowledge of their clinicopathological features would help clinicians to manage gallbladder lesions associated with ADM or XCG.

Surgery for gallbladder cancer in the US: a need for greater lymph node clearance

BACKGROUND

Gallbladder cancer (GBC) is a rare malignancy with a dismal prognosis. Often identified incidentally after laparoscopic cholecystectomy for presumably benign biliary disease, reoperation with partial hepatic resection and periportal lymph node dissection (LND) is frequently performed. The impact of lymph node (LN) clearance for GBC remains unclear.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was queried for patients diagnosed with GBC between 1988 and 2009. Survival was calculated using Kaplan-Meier method and compared using log-rank test. Multivariate analysis was performed to identify predictors of survival.

RESULTS

A total of 11,815 patients diagnosed with GBC were identified. Cancer-directed surgery was performed in 8,436 (71.3%) patients. Optimal LN clearance (defined as ≥4 LNs) is associated with young age, advanced T-stage, no radiation therapy, and radical surgery (all <0.001). Greater LND improves survival for all stages (P<0.001). After adjusting for confounding factors, multivariable analysis of patients with node-negative disease demonstrated that early stage, greater LND, and radical surgery were strong independent predictors of survival.

CONCLUSIONS

Extensive lymphadenectomy correlates with longer survival even in node negative patients. Extensive LND should be performed in patients with GBC as many patients in the USA are undertreated.

Association of cancer stem cell markers genetic variants with gallbladder cancer susceptibility, prognosis, and survival

Genes important to stem cell progression have been involved in the genetics and clinical outcome of cancers. We investigated germ line variants in cancer stem cell (CSC) genes to predict susceptibility and efficacy of chemoradiotherapy treatment in gallbladder cancer (GBC) patients. In this study, we assessed the effect of SNPs in CSC genes (surface markers CD44, ALCAM, EpCAM, CD133) and (molecular markers NANOG, SOX-2, LIN-28A, ALDH1A1, OCT-4) with GBC susceptibility and prognosis. Total 610 GBC patients and 250 controls were genotyped by using PCR-RFLP, ARMS-PCR, and TaqMan allelic discrimination assays. Chemotoxicity graded 2-4 in 200 patients and tumor response was recorded in 140 patients undergoing neoadjuvant chemotherapy (NACT). Differences in genotype and haplotype frequency distributions were calculated by binary logistic regression. Gene-gene interaction model was analyzed by generalized multifactor dimensionality reduction (GMDR). Overall survival was assessed by Kaplan-Meier survival curve and multivariate Cox-proportional methods. ALCAM Ars1157Crs10511244 (P = 0.0035) haplotype was significantly associated with GBC susceptibility. In GMDR analysis, ALCAM rs1157G>A, EpCAM rs1126497T>C emerged as best significant interaction model with GBC susceptibility and ALDH1A1 rs13959T>G with increased risk of grade 3-4 hematological toxicity. SOX-2 rs11915160A>C, OCT-4 rs3130932T>G, and NANOG rs11055786T>C were found best gene-gene interaction model for predicting response to NACT. In both Cox-proportional and recursive partitioning ALCAM rs1157GA+AA genotype showed higher mortality and hazard ratio. ALCAM gene polymorphisms associated with GBC susceptibility and survival while OCT-4, SOX-2, and NANOG variants showed an interactive role with treatment response.

PSCA gene variants (rs2294008 and rs2978974) confer increased susceptibility of gallbladder carcinoma in females

BACKGROUND AND AIM

PSCA is a tissue specific tumor suppressor or oncogene which has been found to be associated with several human tumors including gallbladder cancer. It is considered to be involved in the cell-proliferation inhibition and/or cell-death induction activity. Therefore, we aimed to investigate the role of PSCA gene polymorphisms in gallbladder cancer risk in North Indian population.

METHODOLOGY

A total of 405 gallbladder cancer patients and 247 healthy controls were included in the case-control study for risk prediction. We examined the association of two functional SNPs, rs2294008 and rs2978974 in PSCA gene by genotyping using Taqman allelic discrimination assays. Statistical analysis was done using SPSS software, version 17. Linkage disequilibrium and haplotype analysis was done with the help of SNPstats software. FDR test was used to correct for multiple comparisons.

RESULTS

No significant associations of rs2294008 and rs2978974 genetic variants of the PSCA gene were found with GBC risk at allele, genotype or haplotype levels. Stratifying the subjects on the basis of gallstone also did not show any significant result. However, on gender stratification, we found a significant association of Trs2294008-Grs2978974 haplotype with higher risk of GBC in females (FDR Pcorr=0.021, OR=1.6). In contrary, Trs2294008-A rs2978974 haplotype conferred significant lower risk in males (FDR Pcorr=0.013; OR=0.25).

CONCLUSIONS

These findings suggest that PSCA genetic variants may have a significant effect on GBC susceptibility in a gender specific manner.