Low prevalence of biliary tract cancer with defective mismatch repair genes in a Japanese hospital-based population

Targeted Therapies in Advanced Cholangiocarcinoma

Primary tumor resection and liver transplantation are the only curative treatment options for the management of cholangiocarcinoma (CCA). However, for patients with advanced or metastatic disease, palliative systemic therapy remains the only treatment option. The development of targeted therapeutics has begun to shift the treatment paradigm in CCA. Targets of interest in CCA include mutated isocitrate dehydrogenase-1 (mIDH-1), human epidermal growth factor receptor 2 (HER2) overexpression/amplification, and fibroblast growth factor receptor 2 (FGFR2) fusion, in addition to less frequently observed targets such as BRAF V600E, deficient mismatch repair/high microsatellite instability (dMMR/MSI-H), and high tumor mutation burden (TMB-H). These targets are observed in varying frequency among patients with intrahepatic CCA and extrahepatic CCA. Multiple novel therapies have been developed to exploit each of these targets, with some having received United States Food and Drug Administration approval for use in the second-line setting. In the current review, we discuss targets of interest in CCA and summarize current evidence evaluating available therapies directed at these targets.

Discordant microsatellite instability findings in two samples from a patient with biliary cancer that responded to pembrolizumab

Microsatellite instability (MSI) is a key marker to predict response to immune checkpoint inhibitors; however, only 1-2% of biliary cancers have this genomic feature. In a patient with hilar biliary cancer, MSI was examined in two cancer specimens (forceps biopsy from the biliary stricture and endoscopic ultrasound-guided fine-needle aspiration biopsy [EUS-FNAB] from the adjacent lymph node). We observed discordant results, as high frequency of MSI was found only in the forceps biopsy. Although the FNAB sample was 10 times larger than that of the forceps biopsy, the tumor concentration was much lower, which is a possible reason for the discordance. Besides, immunohistochemistry of four mismatch-repair (MMR) proteins showed proficient MMR expressions. The tumor became refractory to gemcitabine, cisplatin, and S-1 but responded well to pembrolizumab. Caution is needed for sample selection and for interpretation of the test's results, to avoid missing rare chance for effective molecular target agents.

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.

Pembrolizumab in combination with gemcitabine and cisplatin compared with gemcitabine and cisplatin alone for patients with advanced biliary tract cancer (KEYNOTE-966): a randomised, double-blind, placebo-controlled, phase 3 trial

BACKGROUND

Biliary tract cancers, which arise from the intrahepatic or extrahepatic bile ducts and the gallbladder, generally have a poor prognosis and are rising in incidence worldwide. The standard-of-care treatment for advanced biliary tract cancer is chemotherapy with gemcitabine and cisplatin. Because most biliary tract cancers have an immune-suppressed microenvironment, immune checkpoint inhibitor monotherapy is associated with a low objective response rate. We aimed to assess whether adding the immune checkpoint inhibitor pembrolizumab to gemcitabine and cisplatin would improve outcomes compared with gemcitabine and cisplatin alone in patients with advanced biliary tract cancer.

METHODS

KEYNOTE-966 was a randomised, double-blind, placebo-controlled, phase 3 trial done at 175 medical centres globally. Eligible participants were aged 18 years or older; had previously untreated, unresectable, locally advanced or metastatic biliary tract cancer; had disease measurable per Response Evaluation Criteria in Solid Tumours version 1.1; and had an Eastern Cooperative Oncology Group performance status of 0 or 1. Eligible participants were randomly assigned (1:1) to pembrolizumab 200 mg or placebo, both administered intravenously every 3 weeks (maximum 35 cycles), in combination with gemcitabine (1000 mg/m2 intravenously on days 1 and 8 every 3 weeks; no maximum duration) and cisplatin (25 mg/m2 intravenously on days 1 and 8 every 3 weeks; maximum 8 cycles). Randomisation was done using a central interactive voice-response system and stratified by geographical region, disease stage, and site of origin in block sizes of four. The primary endpoint of overall survival was evaluated in the intention-to-treat population. The secondary endpoint of safety was evaluated in the as-treated population. This study is registered at ClinicalTrials.gov, NCT04003636.

FINDINGS

Between Oct 4, 2019, and June 8, 2021, 1564 patients were screened for eligibility, 1069 of whom were randomly assigned to pembrolizumab plus gemcitabine and cisplatin (pembrolizumab group; n=533) or placebo plus gemcitabine and cisplatin (placebo group; n=536). Median study follow-up at final analysis was 25·6 months (IQR 21·7-30·4). Median overall survival was 12·7 months (95% CI 11·5-13·6) in the pembrolizumab group versus 10·9 months (9·9-11·6) in the placebo group (hazard ratio 0·83 [95% CI 0·72-0·95]; one-sided p=0·0034 [significance threshold, p=0·0200]). In the as-treated population, the maximum adverse event grade was 3 to 4 in 420 (79%) of 529 participants in the pembrolizumab group and 400 (75%) of 534 in the placebo group; 369 (70%) participants in the pembrolizumab group and 367 (69%) in the placebo group had treatment-related adverse events with a maximum grade of 3 to 4. 31 (6%) participants in the pembrolizumab group and 49 (9%) in the placebo group died due to adverse events, including eight (2%) in the pembrolizumab group and three (1%) in the placebo group who died due to treatment-related adverse events.

INTERPRETATION

Based on a statistically significant, clinically meaningful improvement in overall survival compared with gemcitabine and cisplatin without any new safety signals, pembrolizumab plus gemcitabine and cisplatin could be a new treatment option for patients with previously untreated metastatic or unresectable biliary tract cancer.

FUNDING

Merck Sharp & Dohme, a subsidiary of Merck & Co, Rahway, NJ, USA.

Clinical characteristics of pancreatic and biliary tract cancers in Lynch syndrome: A retrospective analysis from the Finnish National Lynch Syndrome Research Registry

Introduction

Patients with Lynch syndrome (LS) have an increased lifetime risk of pancreatic cancer (PC) and biliary tract cancer (BTC). These cancers have a notoriously pessimistic prognosis due to late diagnosis and limited therapeutic options. There are limited data based on small cohorts reviewing PC and BTC in LS patients.

Methods

In this retrospective study of the Lynch Syndrome Registry of Finland (LSRFi), records of genetically verified LS patients diagnosed with PC or BTC between 1982 and 2020 were analyzed.

Results

Thirty-nine patients were included: tumor(s) were in the pancreas in 26 patients, in the biliary tract in 10, and in the ampulla of Vater in three. A pathogenic germline variant was found in MLH1 in 33 of 39 patients. Twenty-six patients with 28 tumors located in the pancreas were identified: 23 pancreatic ductal adenocarcinomas (PDACs) and five neuroendocrine tumors (NETs). The median age at diagnosis of PC was 64 years (range of 38-81). In PC, the 5-year overall survival (OS) rate was 20%, and in PDAC, it was 13.6%. Ten patients with BTC were diagnosed: two intrahepatic, five perihilar, two distal extrahepatic cholangiocarcinomas, and one gallbladder carcinoma. Eight patients were male, and the median age at diagnosis was 54 years (range of 34-82). The 5-year OS rate for BTC was 30%. Metachronous tumors were diagnosed in 28 patients (70%). Colorectal cancer was the most common metachronous tumor, diagnosed in 20 patients (51%), and diagnosed prior to PC or BTC in all cases. Curative surgery was attempted on 17 of 39 patients. For 30 patients (91%), the cause of death was PC or BTC; two patients died from another LS-associated cancer, and one died from a stroke.

Conclusion

Although the survival of LS patients with PC or BTC is better than in sporadic cancers, it is still poor and may be reflected by the relatively higher surgical resectability accounted for by the earlier age of onset. More studies on analyses of the molecular and immune profile, screening, and management of LS-associated pancreaticobiliary cancers are warranted.

Current and emerging immunotherapeutic approaches for biliary tract cancers

BACKGROUND

Biliary tract cancers (BTCs) comprise a heterogeneous group of aggressive malignancies with unfavorable prognoses. The benefit of chemotherapy seems to have reached a bottleneck and, therefore, new effective therapeutic strategies for advanced BTCs are needed. Molecularly targeted therapies in selected patients are rapidly changing the situation. However, the low frequency of specific driver alterations in BTCs limits their wide application. Recently, immunotherapeutic approaches are also under active investigation in BTCs, but the role of immunotherapy in BTCs remains controversial.

DATA SOURCES

PubMed, Web of Science, and meeting resources were searched for relevant articles published from January 2017 to May 2022. The search aimed to identify current and emerging immunotherapeutic approaches for BTCs. Information on clinical trials was obtained from https://clinicaltrials.gov/ and http://www.chictr.org.cn/.

RESULTS

Immunotherapy in BTC patients is currently under investigation, and most of the investigations focused on the application of immune checkpoint inhibitors (ICIs). However, only a subgroup of BTCs with microsatellite-instability high (MSI-H)/DNA mismatch repair-deficient (dMMR) or tumor mutational burden-high (TMB-H) benefit from monotherapy of ICIs, and limited activity was observed in the second or subsequent settings. Nevertheless, promising results come from studies of ICIs in combination with other therapeutic approaches, including chemotherapy, in advanced BTCs, with a moderate toxicity profile. Recent studies demonstrated that compared to GEMCIS alone, durvalumab plus GEMCIS significantly improved patient survival (TOPAZ-1 trial) and that ICIs-combined chemoimmunotherapy is poised to become a new frontline therapy option, regardless of TMB and MMR/MSI status. Adoptive cell therapy and peptide- or dendritic-based cancer vaccines are other immunotherapeutic options that are being studied in BTCs. Numerous biomarkers have been investigated to define their predictive role in response to ICIs, but no predictive biomarker has been validated, except MSI-H/dMMR.

CONCLUSIONS

The role of immunotherapy in BTCs is currently under investigation and the results of ongoing studies are eagerly anticipated. Several studies have demonstrated the safety and efficacy of ICIs in combination with chemotherapy in treatment-naive patients, such as the phase III TOPAZ-1 trial, which will change the standard care of first-line chemotherapy for advanced BTCs. However, further research is needed to understand the best combination with immunotherapy and to discover more predictive biomarkers to guide clinical practice.

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.

Long-Term Survival of a Lynch Syndrome Patient With Eight Primary Tumors: A Case Report

With the modern technological developments in the diagnosis and treatment of cancer, the survival rate of cancer patients has increased. On the other hand, the incidence of multiple primary tumors is increasing annually. Lynch syndrome (LS), an autosomal dominant disorder with germline mutations in DNA mismatch repair genes, increases the risk of cancer in patients carrying those mutations. In this report, we present an extremely rare case of an 81-year-old male patient with eight primary malignancies and LS. The patient is still alive having survived for more than 41 years since the initial discovery of the first tumor. The eighth and most recently diagnosed primary cancer was a malignant peripheral nerve sheath tumor. Although there have been numerous reports of malignancies in LS, malignant peripheral nerve sheath tumors have not been reported previously with LS. Here, we report, to the best of our knowledge, the first case of a malignant peripheral nerve sheath tumor with LS.