Low frequency of mismatch repair deficiency in gallbladder cancer

PD-L1 expression in pancreaticobiliary adenosquamous carcinoma: a single-institution case series

Background

The programmed cell death protein 1 (PD-1)/programmed cell death ligand 1 (PD-L1) pathway is a potent negative regulator of T-cell-mediated immune response that is upregulated in many neoplasms. Pancreaticobiliary adenosquamous carcinoma (PB-ASC) is an aggressive cancer that carries a poorer prognosis compared with pure pancreaticobiliary adenocarcinoma (PB-AC). To date, there is little published information regarding PD-L1 expression in PB-ASC. The aim of the study was to examine the relationship between PD-L1 expression and tumor-infiltrating lymphocytes in PB-ASC and PB-AC.

Methods

We evaluated 15 PB-ASCs (10 pancreatic, 5 gallbladder) and 34 control PB-ACs (22 pancreatic ductal, and 12 gallbladder) for tumor expression of PD-L1 using anti-PD-L1 (E1L3N) antibody. All tumors were classified into three immune phenotypes: immune inflamed (II), immune excluded (IE), and immune desert (ID) according to the distribution of tumor-infiltrating lymphocytes in tumor tissues.

Results

The frequency of PD-L1 expression was significantly higher in PB-ASC (10/15; 66.7%) than in PB-AC (3/34; 8.8%). In PB-ASC, PD-L1 expression occurred exclusively in the squamous component in six cases, exclusively in the glandular component in one case, and in both the squamous and the glandular components in three cases. PD-L1 expression in PB-ASC was irrespective of the tumor immune status, whereas its expression in PB-AC was observed only in tumors with the II or IE phenotype. The ID phenotype was relatively rare (4/15; 26.7%) in PB-ASC compared with PB-AC (22/34; 65%; P=0.02).

Conclusions

PB-ASCs are notably enriched in inflammatory response and showed significantly higher PD-L1 expression than PB-AC (P<0.001), suggesting a potential therapeutic role for immune checkpoint inhibitors in managing patients with PB-ASC.

Molecular pathology for cholangiocarcinoma: a review of actionable genetic targets and their relevance to adjuvant & neoadjuvant therapy, staging, follow-up, and determination of minimal residual disease

Cholangiocarcinoma (CCA) represents a group of epithelial cell tumors classified based on their anatomic location along the biliary tree. This rare malignancy is often diagnosed at an advanced stage and deemed unresectable. Even for those patients who are surgical candidates, recurrence rates are high and survival rates low. The mainstay of therapy for advanced CCA remains cisplatin plus gemcitabine, with a median overall survival (mOS) under 12 months, although the TOPAZ-1 trial showed a survival benefit with the addition of programmed cell death ligand 1 (PD-L1) blockade. In recent years, molecular profiling has revealed a wealth of potentially targetable genetic alterations, including fibroblast growth factor receptor (FGFR) fusions, isocitrate dehydrogenase 1 (IDH1) mutations, human epidermal growth factor receptor 2 (HER2) amplification and overexpression, and microsatellite instability (MSI). These discoveries have prompted numerous clinical trials employing drugs against these specific genetic changes. The foundation laid by early clinical studies and the landscape of ongoing trials are both summarized here. While the role of adjuvant therapy has yet to be defined in this disease, we emphasize the importance of employing targeted therapies in trials in the adjuvant and neoadjuvant spaces and discuss ways to overcome challenges due to low incidence of targetable mutations. Personalized medicine for this disease promises significant clinical benefit to patients, but further investigation is needed.

Mismatch Repair Deficiency in Biliary Tract Cancer: Prognostic Implications and Correlation with Histology

INTRODUCTION

Mismatch repair (MMR) deficiency represents a biomarker and therapeutic target in various neoplasms, but its role in biliary tract cancers (BTCs) remains misunderstood.

METHODS

MMR status was retrospectively assessed using immunohistochemistry in 163-BTCs patients. We identified MMR proficiency (pMMR)/deficiency (dMMR) according to the loss of MMR proteins (MLH1, PMS2, MSH2, MSH6). The primary objective of the study was to assess the incidence of dMMR in BTCs; the secondary purpose was to explore its association with prognosis and clinical features.

RESULTS

dMMR was recorded in 9 patients, and it was strongly associated with mucinous histology (p < 0.01). Regarding the prognostic effect, in 122-radically resected patients, disease-free survival (DFS) resulted significantly shorter in dMMR patients compared to pMMR patients (10.7 vs. 31.3 months, p = 0.025) and so did nodal status (48.2 vs. 15.3 months in N0 vs. N+) (p < 0.01). Moreover, dMMR confirmed its prognostic role in terms of DFS at multivariate analysis (p = 0.03), together with nodal status (p = 0.01), and resection margin (p = 0.03). In 103 M+ patients (encompassing 41 metastatic de novo and 62 recurred after surgery patients) there were not differences between dMMR and pMMR regarding survival analyses.

CONCLUSIONS

dMMR status is strongly correlated with mucinous histology and represents an independent prognostic factor in terms of disease relapse in patients with resected BTC.

IMPLICATIONS FOR PRACTICE

MMR may play an independent role in promoting an aggressive behaviour in patients with radically resected BTC. These results could be useful in improving the selection of patients after resection and, above all, should justify the evaluation of MMR status as a therapeutic target in BTC, especially in patients with atypical histology.

Lacking Immunotherapy Biomarkers for Biliary Tract Cancer: A Comprehensive Systematic Literature Review and Meta-Analysis

BACKGROUND

Immunotherapy has recently been incorporated into the spectrum of biliary tract cancer (BTC) treatment. The identification of predictive response biomarkers is essential in order to identify those patients who may benefit most from this novel treatment option. Here, we propose a systematic literature review and a meta-analysis of PD-1, PD-L1, and other immune-related biomarker expression levels in patients with BTC.

METHODS

Prisma guidelines were followed for this systematic review and meta-analysis. Eligible studies were searched on PubMed. Studies published between 2017 and 2022, reporting data on PD-1/PD-L1 expression and other immune-related biomarkers in patients with BTC, were considered eligible.

RESULTS

A total of 61 eligible studies were identified. Despite the great heterogeneity between 39 studies reporting data on PD-L1 expression, we found a mean PD-L1 expression percentage (by choosing the lowest cut-off per study) of 25.6% (95% CI 21.0 to 30.3) in BTCs. The mean expression percentages of PD-L1 were 27.3%, 21.3%, and 27.4% in intrahepatic cholangiocarcinomas (iCCAs-15 studies), perihilar-distal CCAs (p/dCCAs-7 studies), and gallbladder cancer (GBC-5 studies), respectively. Furthermore, 4.6% (95% CI 2.38 to 6.97) and 2.5% (95% CI 1.75 to 3.34) of BTCs could be classified as TMB-H and MSI/MMRd tumors, respectively.

CONCLUSION

From our analysis, PD-L1 expression was found to occur approximately in 26% of BTC patients, with minimal differences based on anatomical location. TMB-H and MSI molecular phenotypes occurred less frequently. We still lack a reliable biomarker, especially in patients with mismatch-proficient tumors, and we must need to make an effort to conceive new prospective biomarker discovery studies.

Gallbladder cancer

Gallbladder cancer (GBC) is the most common cancer of the biliary tract, characterized by a very poor prognosis when diagnosed at advanced stages owing to its aggressive behaviour and limited therapeutic options. Early detection at a curable stage remains challenging because patients rarely exhibit symptoms; indeed, most GBCs are discovered incidentally following cholecystectomy for symptomatic gallbladder stones. Long-standing chronic inflammation is an important driver of GBC, regardless of the lithiasic or non-lithiasic origin. Advances in omics technologies have provided a deeper understanding of GBC pathogenesis, uncovering mechanisms associated with inflammation-driven tumour initiation and progression. Surgical resection is the only treatment with curative intent for GBC but very few cases are suitable for resection and most adjuvant therapy has a very low response rate. Several unmet clinical needs require to be addressed to improve GBC management, including discovery and validation of reliable biomarkers for screening, therapy selection and prognosis. Standardization of preneoplastic and neoplastic lesion nomenclature, as well as surgical specimen processing and sampling, now provides reproducible and comparable research data that provide a basis for identifying and implementing early detection strategies and improving drug discovery. Advances in the understanding of next-generation sequencing, multidisciplinary care for GBC, neoadjuvant and adjuvant strategies, and novel systemic therapies including chemotherapy and immunotherapies are gradually changing the treatment paradigm and prognosis of this recalcitrant cancer.

Current Immune Checkpoint Inhibitor Genetic Biomarker Exploration in Gastrointestinal Tumors

Simple Summary

Immune checkpoint inhibitors (ICIs) are now incorporated into the management of GI tumors. The heterogenous nature of these tumors, however, reveals a lack of ICI consistency in effectiveness. Certain biomarkers have emerged as being potentially predictive for ICI effectiveness. Our review focuses on these biomarkers while discussing the current limitations with these markers.

Abstract

Immune checkpoint inhibitors have revolutionized cancer management. Some patients with gastrointestinal (GI) tract malignancy have experienced remarkable results. Here, in our review, we discuss predictive/prognostic GI tumor biomarkers that appear to correlate with benefits with this strategy. Remarkable progress has been made in certain subsets of patients including the potential for solid tumor patients to avoid local therapies such as radiation and/or surgery (organ preservation), which come with acute and chronic risks that have historically been the only curable strategies for these GI tumors. These results provide new and exciting strategies for solid tumor management. Unfortunately, immune checkpoint inhibitors can correlate with biomarkers, but benefits occur in a small subset of patients with GI malignancies. Most frequently, immune checkpoint inhibitors fail to induce response in GI malignancies due to the “cold” tumor microenvironment that protects cancer. Translational strategies are needed to develop effective combination strategies and novel biomarkers to overcome the intrinsic resistance.

Novel immune scoring dynamic nomograms based on B7-H3, B7-H4, and HHLA2: Potential prediction in survival and immunotherapeutic efficacy for gallbladder cancer

Background

Gallbladder cancer (GBC) is a mortal malignancy with limited therapeutic strategies. We aimed to develop novel immune scoring systems focusing on B7-H3, B7-H4, and HHLA2. We further investigated their potential clinical effects in predicting survival and immunotherapeutic efficacy for GBC.

Methods

This was a retrospective cohort study in a single center that explored the expression characteristics of B7-H3, B7-H4, and HHLA2. The immune scoring nomograms for prognostic were developed via logistic regression analyses. Their performance was evaluated using the Harrell concordance index (C-index) and decision curves analysis (DCA), and validated with calibration curves.

Results

B7-H3, B7-H4, and HHLA2 manifested with a relatively high rate of co-expression patterns in GBC tissues. They were associated with worse clinicopathological stage, suppression of immune microenvironment, and unfavorable prognosis in postoperative survival. B7 stratification established based on B7-H3, B7-H4, and HHLA2 was an independent prognostic predictor (p&lt;0.05 in both groups). Moreover, immune stratification was also successfully constructed based on B7 stratification and the density of CD8+ TILs (all p&lt;0.001). The prediction models were developed based on B7-/or immune stratification combined with the TNM/or Nevin staging system. These novel models have excellent discrimination ability in predicting survival and immunotherapeutic efficacy for GBC patients by DCA and clinical impact plots. Finally, dynamic nomograms were developed for the most promising clinical prediction models (B7-TNM model and Immune-TNM model) to facilitate prediction.

Conclusions

Immune scoring systems focusing on B7-H3, B7-H4, and HHLA2 may effectively stratify the prognosis of GBC. Prognostic nomograms based on novel immune scoring systems may potentially predict survival and immunotherapeutic efficacy in GBC. Further valid verification is necessary.

Durvalumab plus Gemcitabine and Cisplatin in Advanced Biliary Tract Cancer

BACKGROUND: Patients with advanced biliary tract cancer have a poor prognosis, and first-line standard of care (gemcitabine plus cisplatin) has remained unchanged for more than 10 years. The TOPAZ-1 trial evaluated durvalumab plus chemotherapy for patients with advanced biliary tract cancer. METHODS: In this double-blind, placebo-controlled, phase 3 study, we randomly assigned patients with previously untreated unresectable or metastatic biliary tract cancer or with recurrent disease 1:1 to receive durvalumab or placebo in combination with gemcitabine plus cisplatin for up to eight cycles, followed by durvalumab or placebo monotherapy until disease progression or unacceptable toxicity. The primary objective was to assess overall survival. Secondary end points included progression-free survival, objective response rate, and safety. RESULTS: Overall, 685 patients were randomly assigned to durvalumab (n=341) or placebo (n=344) with chemotherapy. As of data cutoff, 198 patients (58.1%) in the durvalumab group and 226 patients (65.7%) in the placebo group had died. The hazard ratio for overall survival was 0.80 (95% confidence interval [CI], 0.66 to 0.97; P=0.021). The estimated 24-month overall survival rate was 24.9% (95% CI, 17.9 to 32.5) for durvalumab and 10.4% (95% CI, 4.7 to 18.8) for placebo. The hazard ratio for progression-free survival was 0.75 (95% CI, 0.63 to 0.89; P=0.001). Objective response rates were 26.7% with durvalumab and 18.7% with placebo. The incidences of grade 3 or 4 adverse events were 75.7% and 77.8% with durvalumab and placebo, respectively. CONCLUSIONS: Durvalumab plus chemotherapy significantly improved overall survival versus placebo plus chemotherapy and showed improvements versus placebo plus chemotherapy in prespecified secondary end points including progression-free survival and objective response rate. The safety profiles of the two treatment groups were similar. (Funded by AstraZeneca; ClinicalTrials.gov number, NCT03875235.)

Microsatellite instability in patients with hepato-biliary-pancreatic malignancies in clinical practice (KHBO 1903)

BACKGROUND

This study aimed to determine the prevalence of microsatellite instability (MSI)-high status in hepato-biliary-pancreatic malignancies in clinical practice and the clinical characteristics of and therapeutic results of pembrolizumab on patients with MSI-high cancers.

METHODS

The subjects were 283 patients who had undergone MSI tests for unresectable, metastatic hepato-biliary-pancreatic malignancies at seven hospitals. The tests were polymerase chain reaction fragment analyses using the microsatellite markers consisting of BAT25, BAT26, NR21, NR24, and MONO27. Formalin-fixed, paraffin-embedded blocks, prepared according to the guidelines of the Japan Society of Pathology were used within 4 years after sampling. There were 13 patients with cancers high in MSI, including eight patients receiving pembrolizumab treatment. The clinical characteristics of these patients and therapeutic outcomes of their pembrolizumab treatment were investigated.

RESULTS

MSI-high was detected in 13 (4.6%) of the 283 patients with hepato-biliary-pancreatic malignancies. None of these 13 patients had been diagnosed with Lynch syndrome. Of the Eight patients receiving pembrolizumab, a complete response was observed in three patients, a partial response in one patient, and stable disease in three patients. The objective response rate was 50% and the disease control rate was 87.5%.

CONCLUSION

MSI-high was detected in 4.6% of patients with hepato-biliary-pancreatic malignancies. There was a 50% objective response rate to pembrolizumab treatment for MSI-high cancers. The evaluation of MSI status by the current method using appropriately prepared tissue samples was to be a reliable and accurate approach to both the determination of MSI status and estimation of the effectiveness of pembrolizumab.

Cáncer de vesícula biliar, una visión actual

Introducción. El diagnóstico de cáncer de vesícula biliar se realiza generalmente de forma incidental durante el estudio de las piezas quirúrgicas o cuando la enfermedad está avanzada y se expresa por su diseminación. Muy pocas veces se diagnostica de forma preoperatoria. Corresponde a la neoplasia más común de las vías biliares y su incidencia varía de acuerdo a la región geográfica. La región andina en Latinoamérica presenta una de las mayores incidencias a nivel mundial. Métodos. Se realizó una revisión narrativa de la literatura, para presentar una información actualizada en lo referente a los factores de riesgo (incluyendo las alteraciones genéticas y moleculares), al diagnóstico y al tratamiento de esta patología. Basados en los datos actuales, presentamos algunas recomendaciones dirigidas al diagnóstico temprano, que permita un manejo más adecuado de nuestros pacientes. Resultados. Se han implicado nuevos factores de riesgo relacionados con la etiología del cáncer de vesícula biliar, como la obesidad, factores genéticos y moleculares. A pesar de la disponibilidad de los métodos diagnósticos imagenológicos, no ha ocurrido una importante variación porcentual en cuanto al estadio al momento del diagnóstico. Conclusiones. El manejo quirúrgico del cáncer de vesícula biliar está indicado en los estadios más tempranos de la enfermedad y es importante evaluar las opciones terapéuticas en pacientes con enfermedad avanzada. Se considera de suma importancia el estudio anatomopatológico de la pieza quirúrgica y la revisión del informe por parte del cirujano

The Transmembrane Receptor TIRC7 Identifies a Distinct Subset of Immune Cells with Prognostic Implications in Cholangiocarcinoma

Cholangiocarcinoma (CCA) is a heterogeneous malignancy with a dismal prognosis. Therapeutic options are largely limited to surgery and conventional chemotherapy offers limited benefit. As immunotherapy has proven highly effective in various cancer types, we have undertaken a quantitative immunohistopathological assessment of immune cells expressing the immunoinhibitory T cell immune response cDNA 7 receptor (TIRC7), an emerging immunoinhibitory receptor, in a cohort of 135 CCA patients. TIRC7+ immune cells were present in both the tumor epithelia and stroma in the majority of CCA cases with the highest levels found in intrahepatic CCA. While intraepithelial density of TIRC7+ immune cells was decreased compared to matched non-neoplastic bile ducts, stromal quantity was higher in the tumor samples. Tumors exhibiting signet ring cell or adenosquamous morphology were exclusively associated with an intraepithelial TIRC7+ phenotype. Survival analysis showed intraepithelial TIRC7+ immune cell density to be a highly significant favorable prognosticator in intrahepatic but not proximal or distal CCA. Furthermore, intraepithelial TIRC7+ immune cell density correlated with the number of intraepithelial CD8+ immune cells and with the total number of CD4+ immune cells. Our results suggest the presence and prognostic relevance of TIRC7+ immune cells in CCA and warrant further functional studies on its pharmacological modulation.

Gallbladder Cancer: Current Insights in Genetic Alterations and Their Possible Therapeutic Implications

Due to the fast progression in molecular technologies such as next-generation sequencing, knowledge of genetic alterations in gallbladder cancer (GBC) increases. This systematic review provides an overview of frequently occurring genetic alterations occurring in GBC and their possible therapeutic implications. A literature search was performed utilizing PubMed, EMBASE, Cochrane Library, and Web of Science. Only studies reporting genetic alterations in human GBC were included. In total, data were extracted from 62 articles, describing a total of 3893 GBC samples. Frequently detected genetic alterations (>5% in >5 samples across all studies) in GBC for which targeted therapies are available in other cancer types included mutations in ATM, ERBB2, and PIK3CA, and ERBB2 amplifications. High tumor mutational burden (TMB-H) and microsatellite instability (MSI-H) were infrequently observed in GBC (1.7% and 3.5%, respectively). For solid cancers with TMB-H or MSI-H pembrolizumab is FDA-approved and shows an objective response rates of 50% for TMB-H GBC and 41% for MSI-H biliary tract cancer. Only nine clinical trials evaluated targeted therapies in GBC directed at frequently altered genes (ERBB2, ARID1A, ATM, and KRAS). This underlines the challenges to perform such clinical trials in this rare, heterogeneous cancer type and emphasizes the need for multicenter clinical trials.

Immune Microenvironment in Gallbladder Adenocarcinomas

Programmed death-1 (PD1) expression has not been reported in gallbladder adenocarcinoma. In this study we examined PD1 expression in gallbladder cancer to explore the correlation between PD1 expression and the clinicopathologic parameters. We found that 98% (46/47) cases expressed programmed death-ligand 1 (PD-L1) with 85% cases being PD-L1 3+. PD1+ tumor-infiltrating lymphocytes (TILs) were present in 78.7% cases (37/47). The tumor size was significantly smaller and the stromal CD3+ TILs were significantly higher in tumors with PD1+ TILs than those with PD1- TILs. In the tumors with size of <3 cm, stromal CD3+ TILs >115/HPF or stromal CD8+ TILs >45/HPF were associated with much better survival than those with stromal CD3+ TILs ≤115/HPF or stromal CD8+ TILs ≤45/HPF. In tumors with the size of 3 cm or larger, PD1+ TILs or stromal CD8+ TILs >45/HPF carried a significantly poorer survival than PD1- tumors or stromal CD8+ TILs <=45/HPF. No correlation was identified between PD1 expression and lymphovascular invasion, distant metastasis, pathologic tumor stage or prognostic stage. Multivariate survival analysis showed that tumor TNM stage and age were independent prognostic factors in gallbladder adenocarcinomas. We conclude that gallbladder adenocarcinomas may have high PD-L1 expression and PD1+ TILs. Smaller tumor size and greater amount of stromal CD3+ T cells were found in tumors with PD1+ TILs. In small tumors (<3 cm), high stromal CD3+ TILs or high stromal CD8+ TILs were associated with better survival. However, in large tumors (≥3 cm), PD1+ TILs or high stromal CD8+ TILs carried a poorer survival. Our study implied that immune-based therapy including PD1/PD-L1 checkpoint blockade might be useful in gallbladder adenocarcinomas.

Highly sensitive duplex MSI test and BAT40 germline polymorphism

Tumors exhibiting DNA mismatch repair (MMR) deficiency and microsatellite instability (MSI) are responsive to immune checkpoint blockade. MSI is frequently diagnosed using five quasimonomorphic mononucleotide (pentaplex) markers; however, the assays have several technical limitations, including the lack of sensitivity of some of the markers. Although markers with increased sensitivity, such as CAT25 and BAT40, have been introduced, the majority of multiplex MSI tests have only been studied in Western populations and require further evaluation in an Asian cohort. This study tested the efficacy of BAT26, CAT25, and BAT40 mononucleotide MSI markers via triplex PCR on 300 samples from patients with advanced cancers from a Korean clinical population. The results were directly compared with those of a pentaplex MSI test and tumor mutation burden (TMB) status, and an additional 60 MSI-H cancers were used for further validation. Four (1.3%) out of 300 advanced tumors were MSI-high (MSI-H). In the pentaplex PCR assay, two colorectal cancers (0.7%) exhibited instability only with the BAT25 mononucleotide marker and were interpreted as MSI-low (MSI-L). In the triplex PCR assay, BAT40 was unstable in 64 cases (21%) and the results did not overlap with those of MSI-L from pentaplex. Given the high frequency of isolated BAT40 instability, we performed the same triplex PCR with DNA obtained from normal controls and found BAT40 polymorphisms in 37 cases (90%). Interestingly, the median TMB of the cases with BAT40 polymorphism was significantly higher (7.0 mt/Mb) than that of BAT40 wild-type cases (5.5 mt/Mb) (p = 0.003). The triplex PCR results from 60 additional MSI-H cancers correlated perfectly (100%) with those of pentaplex PCR, and the results were consistent for two (BAT26 and CAT25) markers. BAT40 germline polymorphism is common in the Korean population and is associated with higher TMB values. The simple duplex (BAT26 and CAT25) MSI test provided the same sensitivity and specificity as pentaplex PCR tests.

Programmed Death Ligand-1 (PD-L1) Is an Independent Negative Prognosticator in Western-World Gallbladder Cancer

Inhibition of the programmed cell death protein-1/ligand-1 (PD-1/PD-L1) axis has opened a new era in the treatment of solid cancers. However, there is no data on the expression and relevance of PD-L1 in Western gallbladder cancer (GBC). We assessed PD-L1 immunohistochemically in 131 GBC patients as Tumor Proportion Score (TPS), Immune Cell Score (IC) and Combined Positivity Score (CPS). Tumor cells expressed PD-L1 in a subset of 14.7% GBC patients at a TPS cut-off of 1%. Higher PD-L1 levels above 10% and 25% TPS were reached in 4.7% and 3.1% of GBC cases, respectively. At a 10% cut-off, TPS was associated with distinct histomorphological subtypes and correlated with poor tumor differentiation. Survival analysis revealed a TPS above 10% to be a highly significant and independent negative prognosticator in GBC. PD-L1 expression was associated with increased CD4+, CD8+ and PD-1+ immune cell densities. In 14.8% of the cases, scattered immune cells expressed T-cell immunoreceptor with Ig and ITIM domains (TIGIT), which was correlated to tumoral expression of its ligand CD155. We here show that a high PD-L1 expression confers a negative prognostic value in Western-world GBC and highlight the TIGIT/CD155 immune checkpoint as a potential new target for GBC immunotherapy.

Current Progress and Future Perspectives of Immune Checkpoint Inhibitors in Biliary Tract Cancer

Biliary tract cancer (BTC) is an uncommon and aggressive neoplasm, with most patients presenting in an advanced stage. Systemic chemotherapy is the limited treatment available but is unsatisfactory, while targeted therapy is still awaiting validation from clinical trials. Given the potential effect of immune checkpoint inhibitors (ICIs) in the treatment of BTC, this review aims to summarize the evidence-based benefits and predictive biomarkers for using inhibitors of cytotoxic T-lymphocyte-associated protein-4 (CTLA-4) ligand, or programmed cell death protein-1 and its ligand (PD-1 and PD-L1) as monotherapy or combined with other anti-tumor therapies, while also pointing out certain pitfalls with the use of ICIs which need to be addressed.

How Should We Test for Lynch Syndrome? A Review of Current Guidelines and Future Strategies

International guidelines for the diagnosis of Lynch syndrome (LS) recommend molecular screening of colorectal cancers (CRCs) to identify patients for germline mismatch repair (MMR) gene testing. As our understanding of the LS phenotype and diagnostic technologies have advanced, there is a need to review these guidelines and new screening opportunities. We discuss the barriers to implementation of current guidelines, as well as guideline limitations, and highlight new technologies and knowledge that may address these. We also discuss alternative screening strategies to increase the rate of LS diagnoses. In particular, the focus of current guidance on CRCs means that approximately half of Lynch-spectrum tumours occurring in unknown male LS carriers, and only one-third in female LS carriers, will trigger testing for LS. There is increasing pressure to expand guidelines to include molecular screening of endometrial cancers, the most frequent cancer in female LS carriers. Furthermore, we collate the evidence to support MMR deficiency testing of other Lynch-spectrum tumours to screen for LS. However, a reliance on tumour tissue limits preoperative testing and, therefore, diagnosis prior to malignancy. The recent successes of functional assays to detect microsatellite instability or MMR deficiency in non-neoplastic tissues suggest that future diagnostic pipelines could become independent of tumour tissue.

Efficacy and Safety of Pembrolizumab for Gemcitabine/Cisplatin-Refractory Biliary Tract Cancer: A Multicenter Retrospective Study

Pembrolizumab, an anti-programmed cell death (PD)-1 monoclonal antibody, is an anticancer agent showing substantial benefit in lung cancer and melanoma treatment. Biliary tract cancer (BTC) has been shown to respond to pembrolizumab; however, no credible data of such treatment outcomes exist. Therefore, we assessed the clinical outcomes and safety of pembrolizumab in patients with gemcitabine/cisplatin-refractory BTC. In this multicenter study, we retrospectively analyzed 51 patients with programmed cell death 1-ligand 1 (PD-L1)-positive gemcitabine/cisplatin-refractory BTC treated with pembrolizumab in four tertiary hospitals in Korea. PD-L1 positivity was defined as the expression of PD-L1 in ≥1% of tumor cells based on immunohistochemical staining (22C3, SP263, and E1L3N assays). The median age of the patients was 66 (range, 43–83) years and 29 (56.9%) were male. Extrahepatic cholangiocarcinoma was the most common cancer type (n = 30, 58.8%). Partial response and stable disease were achieved in 5 (9.8%) and 13 (25.5%) patients, respectively. Median progression-free survival and overall survival were 2.1 (95% CI, 1.7–2.4) and 6.9 (95% CI, 5.4–8.3) months, respectively. Overall, 30 (58.8%) patients experienced treatment-related adverse events (AEs). Only four (7.8%) patients experienced grades 3 and 4 AEs. In PD-L1-positive gemcitabine/cisplatin-refractory BTC, pembrolizumab presented durable efficacy, with a 9.8% response rate and manageable toxicity.

Genomic Landscape and Targeted Treatment of Gallbladder Cancer: Results of a First Ongoing Prospective Study

Background  Prognosis of gallbladder cancer (GBC) has not changed in the past 20 years. Comprehensive genomic profiling (CGP) carries potential to determine the actionability for multiple targets, including ERBB2 , ERBB3 , MET , ROSI , FGFR , and PIK3 . This study evaluates the role of CGP and targeted therapies. Methods  This is a multicenter, prospective, single-arm study. All consecutive patients of unresectable and/or metastatic GBC of age ≥18 years were enrolled. Hybrid capture-based CGP was performed by Foundation Medicine CDx. All patients received first-line chemotherapy with gemcitabine-cisplatin regimen. Patients with ERBB2/3 amplification received trastuzumab with capecitabine or nab-paclitaxel, and patients with MET amplification were treated with crizotinib. For ERBB2/3 mutations, lapatinib plus capecitabine regimen was used. Results  Fifty patients were studied with a median age of 56 years (range 26-83) and a male-to-female ratio of 1:1.6. ERBB2 and ERBB3 amplification was seen in 9 (18%) and 2 (4%) patients, respectively. Four patients with ERBB2 amplification received trastuzumab and/or lapatinib, showed partial response, and maintained response beyond 12 weeks. One patient had mixed response, whereas two patients progressed on trastuzumab and lapatinib. Three patients with ERBB3 mutations showed response to lapatinib-capecitabine. One patient with MET amplification responded to crizotinib for 4 weeks. PIK3 mutations were present in 14% of cases and were independent of ERBB aberrations. Conclusion  GBC is enriched in 28% of patients with ERBB2 and ERBB3 amplifications and/or mutations. Responses are seen with lapatinib in concurrent ERBB2 mutation and amplification. ERBB3 mutation showed response to lapatinib. MET and PIK3 are new findings in GBC, which may be targeted.