PD-L1 evaluation in the gastrointestinal tract: from biological rationale to its clinical application

Medullary carcinomas of the nonampullary small intestine: association with coeliac disease, mismatch repair deficiency, PD-L1 expression, and favourable prognosis

AIM

Gastrointestinal medullary carcinoma is a rare histologic subtype of adenocarcinoma. As nonampullary small bowel medullary carcinomas (SB-MCs) are poorly characterized, we aimed to analyse their clinicopathologic and immunohistochemical features and to compare them with nonmedullary small bowel adenocarcinomas (NM-SBAs).

METHODS AND RESULTS

Surgically resected SBAs collected through the Small Bowel Cancer Italian Consortium were classified as SB-MCs (carcinomas with ≥50% of tumour fulfilling the typical histologic criteria of MC) or NM-SBAs. Immunohistochemistry for cytokeratin (CK)7, CK20, CDX2, programmed death-ligand 1 (PD-L1) and mismatch repair proteins was performed in both SB-MCs and NM-SBAs. SB-MCs were also tested for CK8/18, synaptophysin, SMARCB1, SMARCA2, SMARCA4, and ARID1A and for Epstein-Barr virus (EBV)-encoded RNAs by in-situ hybridization. MLH1 promoter methylation status was evaluated in MLH1-deficient cases. Eleven SB-MCs and 149 NM-SBAs were identified. One (9%) SB-MC was EBV-positive, while 10 (91%) harboured mismatch repair deficiency (dMMR). MLH1 promoter hypermethylation was found in all eight dMMR SB-MCs tested. Switch/sucrose nonfermentable deficiency was seen in two (18%) SB-MCs, both with isolated loss of ARID1A. Compared with NM-SBAs, SB-MCs exhibited an association with coeliac disease (P < 0.001), higher rates of dMMR (P < 0.001), and PD-L1 positivity by both tumour proportion score and combined positive score (P < 0.001 for both), and a lower rate of CK20 expression (P = 0.024). Survival analysis revealed a better prognosis of SB-MC patients compared to NM-SBA cases (P = 0.02).

CONCLUSION

SB-MCs represent a distinct histologic subtype, with peculiar features compared to NM-SBAs, including association with coeliac disease, dMMR, PD-L1 expression, and better prognosis.

Myeloid subsets impede the efficacy of anti-PD1 therapy in patients with advanced gastric cancer (WJOG10417GTR study)

BACKGROUND

Gastric cancer (GC) is one of the most common and deadly malignant diseases worldwide. Despite revolutionary advances, the therapeutic efficacy of anti-PD1/PDL1 monoclonal antibodies in advanced GC is still low due to the emergence of innate and acquired resistance to treatment. Myeloid cells represent the majority of human immune cells. Therefore, their increase, decrease, and abnormality could have a significant impact on the patient's immune system and the progression of cancer, and reprogramming, inhibiting, and eliminating the tumor-supportive types may improve the immunological situation and efficacy of immunotherapy. However, the significance of myeloid cells in anti-PD1/PDL1 therapy remains unclear in GC. In the WJOG10417GTR study on GC, we sought to identify myeloid determinants that could predict anti-PD1 therapeutic efficacy and also serve as potential therapeutic targets.

METHODS

We collected tumor tissues and peripheral blood from 96 patients with advanced GC before and 1 month after anti-PD1 nivolumab monotherapy, and the isolated whole leucocytes were analyzed by flow cytometry for various immune cell populations, including many myeloid subsets. Then, the relationship between the cellular levels and progression-free survival (PFS) or overall survival (OS) was statistically analyzed.

RESULTS

We found that high levels of several myeloid subsets expressing molecules that have been targeted in drug discovery but not yet approved for clinical use were significantly associated with shorter PFS/OS as compared with low levels: PDL1+ and CTLA4+ myeloid subsets within tumors at baseline, PDL1+, B7H3+ and CD115+ myeloid subsets in peripheral blood at baseline, and LAG3+, CD155+ and CD115+ myeloid subsets in peripheral blood at post-treatment.

CONCLUSIONS

This study revealed that these myeloid subsets are significant risk factors in nivolumab therapy for advanced GC. Targeting them may be useful as diagnostic biomarkers to predict potential anti-PD1 therapeutic efficacy, and also as therapeutic targets for accelerating the development of new drugs to improve clinical outcomes in immunotherapy for GC.

PD-L1 thresholds predict efficacy of immune checkpoint inhibition in first-line treatment of advanced gastroesophageal adenocarcinoma. A systematic review and meta-analysis of seven phase III randomized trials

BACKGROUND

High expression of programmed death-ligand 1 (PD-L1) has been recognized as a marker of improved efficacy of immunotherapy in gastroesophageal adenocarcinoma (GEA); however, the optimal PD-L1 cut-off is still debated. The aim of the present review was to analyze available phase III trials and to identify the appropriate PD-L1 expression cut-off for GEA.

METHODS

Phase III trials investigating the efficacy of anti-programmed cell death protein 1 (PD-1) therapies in addition to standard chemotherapy versus standard chemotherapy in the first-line setting were selected. Progression-free survival (PFS), overall survival (OS) and objective response rate (ORR) were the analyzed outcome measures. Pooled treatment effects were assessed in the unselected population and in subpopulations with different levels of PD-L1 expression.

RESULTS

PD-1 blockade efficacy was found to consistently increase in a linear manner with higher combined positive score (CPS) of PD-L1 expression: pooled hazard ratio (HR) for OS and PFS and pooled odds ratio (OR) for ORR of 0.80, 0.75 and 1.51, respectively, in the unselected population versus 0.67, 0.63 and 1.90, respectively, in the CPS ≥10 population (all P values < 0.0001). In the PD-L1-negative population (CPS <1) a significant benefit of anti-PD-1 agents could not be demonstrated in terms of OS and PFS (P = 0.28 and 0.12, respectively), but it was seen in terms of ORR (P = 0.03). PD-1 blockade was effective in the CPS <10 population (P value for pooled OS HR, PFS HR and response OR are all 0.01), while in the CPS <5 population the effect was of borderline significance for OS (P = 0.07) and significant for PFS and ORR (P = 0.02 and 0.03, respectively).

CONCLUSION

The present meta-analysis confirmed that the benefit of PD-1 blockade in GEA patients is related to PD-L1 CPS, with increased benefit observed for higher CPS cut-offs and no OS benefit in the CPS <1 subset. Overall, data indicate that PD-L1 CPS ≥5 could represent an acceptable cut-off to optimize the risk/benefit ratio of such agents. Our data suggest a potential clinical benefit of immunotherapy in selected patients within the CPS 1-4 population which needs further investigation.

Claudin-18.2 Immunohistochemical Evaluation in Gastric and Gastroesophageal Junction Adenocarcinomas to Direct Targeted Therapy: A Practical Approach

Claudin-18.2 (CLDN18.2) expression evaluated by immunohistochemistry is a new biomarker for gastric and gastroesophageal junction adenocarcinomas that will soon have market authorization for implementation into routine clinical practice. Despite successful testing in the setting of clinical trials, no specific practical testing guidelines have been proposed. Several preanalytical and analytical variables may interfere with adequate CLDN18.2 staining interpretation; thus, this article provides practical guidance on CLDN18.2 testing and scoring in gastric and gastroesophageal junction adenocarcinomas to identify patients who may respond to targeted therapy with monoclonal antibodies directed against CLDN18.2. Based on available data, moderate to strong (2+/3+) membrane staining in ≥75% of adenocarcinoma cells is the proposed cutoff for clinical use of monoclonal antibody anti-CLDN18.2 (zolbetuximab).

ESM1 facilitates the EGFR/HER3-triggered epithelial-to-mesenchymal transition and progression of gastric cancer via modulating interplay between Akt and angiopoietin-2 signaling

Gastric cancer (GC) poses global challenges due to its difficult early diagnosis and drug resistance, necessitating the identification of early detection markers and understanding of oncogenic pathways for effective GC therapy. Endothelial cell-specific molecule 1 (ESM1), a secreted glycoprotein, is elevated in various cancers, but its role in GC remains controversial. In our study, ESM1 was elevated in GC tissues, and its concentration was correlated with progression and poorer patient prognosis in independent cohorts. Functionally, ESM1 expression promoted proliferation, anoikis resistance, and motility of GC cells, as well as tumor growth in PDOs and in GC xenograft models. Mechanistically, ESM1 expression triggered the epithelial-to-mesenchymal transition (EMT) of GC cells by enhancing epidermal growth factor receptor (EGFR)/human EGFR 3 (HER3) association and activating the EGFR/HER3-Akt pathway. Additionally, angiopoietin-2 (ANGPT2) was found to be highly correlated with ESM1 and interplayed with Akt to induce the EMT and cancer progression. Use of a signal peptide deletion mutant (ESM1-19del) showed that the secreted form of ESM1 is crucial for its protumorigenic effects by activating the EGFR/HER3-Akt/ANGPT2 pathway to promote the EMT. Patients with high levels of both ESM1 and ANGPT2 had the poorest prognoses. Furthermore, therapeutic peptides successfully inhibited ESM1's induction of the aforementioned signals and motility of GC cells. ESM1's oncogenic role in GC involves activating the EGFR/HER3-Akt/ANGPT2 pathway, presenting a potential therapeutic target for GC.

Organoid models: the future companions of personalized drug development

High failure rates of the current drug development process are driving exemplary changes toward methodologies centered on human diseasein-vitromodeling. Organoids are self-organized tissue sub-units resembling their organ of origin and are widely acknowledged for their unique potential in recapitulating human physio-pathological mechanisms. They are transformative for human health by becoming the platform of choice to probe disease mechanisms and advance new therapies. Furthermore, the compounds' validation as therapeutics represents another point of the drug development pipeline where organoids may provide key understandings and help pharma organizations replace or reduce animal research. In this review, we focus on gastrointestinal organoid models, which are currently the most advanced organoid models in drug development. We focus on experimental validations of their value, and we propose avenues to enhance their use in drug discovery and development, as well as precision medicine and diagnostics.

PD-L1 Expression in Colorectal Carcinoma Correlates with the Immune Microenvironment

INTRODUCTION/BACKGROUND

Colorectal carcinoma (CRC) is a common malignancy, with its diverse clinical, pathological, and molecular features. The immune microenvironment of a tumor comprises of interplay between various cells and molecules, and has a significant role in deciding the tumor behavior and overall prognosis. PD-L1 (programmed cell death ligand-1) has been implicated in the regulation of the tumor immune microenvironment (TIME). There is limited data regarding the correlation of PD-L1 expression with immune cell profile in CRCs, especially in the Indian setting. The study aimed to assess the PD-L1 expression in CRC tumor cells and its association with TIME, mismatch repair (MMR), and various other clinicopathological parameters.

METHODS

This is a hospital-based, cross-sectional observational study. PD-L1 expression was assessed at the protein level by immunohistochemistry and mRNA level by qRT-PCR. Immune cell markers (CD4, CD8, CD20, FOXP3, and CD163) were interpreted using the ImageJ Fiji platform.

RESULTS

Of the 104 cases, 21% were PD-L1 positive and were more common in right-sided CRCs. PD-L1 positive cases showed significantly higher concentrations of all T-cell subsets (CD4+ , CD8+ , and FOXP3+), CD20+ B-cells, and CD163+ macrophages were noted. No statistical significance was seen between PD-L1 expression with clinical profile, pathological subtype, grade or stage, mismatch repair status (proficient vs deficient), and survival.

CONCLUSIONS

The present study showed a relatively lower frequency of PD-L1 in CRC from the Eastern Indian cohort. The immune cell concentration in the present study was calculated using image analysis-based objectivised methods. Significant correlation of PD-L1 expression in tumor cells with the tumor-infiltrating immune cells indicated its crucial role in the pathobiology of CRC especially by regulating the TIME. Considering the therapeutic implication of PD-L1 in various malignancies, it may be one of the crucial therapeutic targets in a proportion of cases.

Plant-derived Durvalumab variants show efficient PD-1/PD-L1 blockade and therapeutically favourable FcR binding

Immune checkpoint blocking therapy targeting the PD-1/PD-L1 inhibitory signalling pathway has produced encouraging results in the treatment of a variety of cancers. Durvalumab (Imfinzi®) targeting PD-L1 is currently used for immunotherapy of several tumour malignancies. The Fc region of this IgG1 antibody has been engineered to reduce FcγR interactions with the aim of enhancing blockade of PD-1/PD-L1 interactions without the depletion of PD-L1-expressing immune cells. Here, we used Nicotiana benthamiana to produce four variants of Durvalumab (DL): wild-type IgG1 and its 'Fc-effector-silent' variant (LALAPG) carrying further modifications to increase antibody half-life (YTE); IgG4S228P and its variant (PVA) with Fc mutations to decrease binding to FcγRI. In addition, DL variants were produced with two distinct glycosylation profiles: afucosylated and decorated with α1,6-core fucose. Plant-derived DL variants were compared to the therapeutic antibody regarding their ability to (i) bind to PD-L1, (ii) block PD-1/PD-L1 inhibitory signalling and (iii) engage with the neonatal Fc receptor (FcRn) and various Fcγ receptors. It was found that plant-derived DL variants bind to recombinant PD-L1 and to PD-L1 expressed in gastrointestinal cancer cells and are able to effectively block its interaction with PD-1 on T cells, thereby enhancing their activation. Furthermore, we show a positive impact of Fc amino acid mutations and core fucosylation on DL's therapeutic potential. Compared to Imfinzi®, DL-IgG1 (LALAPG) and DL-IgG4 (PVA)S228P show lower affinity to CD32B inhibitory receptor which can be therapeutically favourable. Importantly, DL-IgG1 (LALAPG) also shows enhanced binding to FcRn, a key determinant of serum half-life of IgGs.

Gastric Cancer, Immunotherapy, and Nutrition: The Role of Microbiota

Immune checkpoint inhibitors (ICI) have revolutionized the treatment of gastric cancer (GC), which still represents the third leading cause of cancer-related death in Western countries. However, ICI treatment outcomes vary between individuals and need to be optimized. Recent studies have shown that gut microbiota could represent a key influencer of immunotherapy responses. At the same time, the nutritional status and diet of GC patients are also predictive of immunotherapy treatment response and survival outcomes. The objective of this narrative review is to gather recent findings about the complex relationships between the oral, gastric, and gut bacterial communities, dietary factors/nutritional parameters, and immunotherapy responses. Perigastric/gut microbiota compositions/functions and their metabolites could be predictive of response to immunotherapy in GC patients and even overall survival. At the same time, the strong influence of diet on the composition of the microbiota could have consequences on immunotherapy responses through the impact of muscle mass in GC patients during immunotherapy. Future studies are needed to define more precisely the dietary factors, such as adequate daily intake of prebiotics, that could counteract the dysbiosis of the GC microbiota and the impaired nutritional status, improving the clinical outcomes of GC patients during immunotherapy.

Predictive and prognostic biomarkers in gastrointestinal tract tumours

Tumours of the gastrointestinal tract represent nearly a quarter of all newly diagnosed tumours diagnosed in 2019. Various treatment modalities for gastrointestinal cancers exist, some of which may be guided by biomarkers. Biomarkers act as gauges of either normal or pathogenic processes or responses to an exposure or intervention. They come in many forms. This review explores established and potential molecular/immunohistochemical (IHC) predictive and prognostic biomarkers of the gastrointestinal tract.

Claudin-18.2 testing and its impact in the therapeutic management of patients with gastric and gastroesophageal adenocarcinomas: A literature review with expert opinion

Claudin-18.2 (CLDN18.2) is a member of the tight junction protein family and is a highly selective biomarker with frequent abnormal expression during the occurrence and development of various primary malignant tumors, including gastric cancer (GC) and esophago-gastric junction adenocarcinomas (EGJA). For these reasons, CLDN18.2 has been investigated as a therapeutic target for GC/EGJA malignancies. Recently, zolbetuximab has been proposed as a new standard of care for patients with CLDN18.2-positive, HER2-negative, locally advanced and metastatic GC/EGJA. The use of CLDN18 IHC assays to select patients who might benefit from anti-CLDN18.2 therapy is currently entering clinical practice. In this setting, pathologists play a central role in therapeutic decision-making. Accurate biomarker assessment is essential to ensure the best therapeutic option for patients. In the present review, we provide a comprehensive overview of available evidence on CLDN18.2 testing and its impact on the therapeutic management of patients with GC/EGJA, as well as some practical suggestions for CLDN18.2 staining interpretation and potential pitfalls in the real-world setting.

Genomic characterization and immunotherapy for microsatellite instability-high in cholangiocarcinoma

BACKGROUND

Microsatellite instability-high (MSI-H) is a unique genomic status in many cancers. However, its role in the genomic features and immunotherapy in cholangiocarcinoma (CCA) is unclear. This study aimed to systematically investigate the genomic characterization and immunotherapy efficacy of MSI-H patients with CCA.

METHODS

We enrolled 887 patients with CCA in this study. Tumor samples were collected for next-generation sequencing. Differences in genomic alterations between the MSI-H and microsatellite stability (MSS) groups were analyzed. We also investigated the survival of PD-1 inhibitor-based immunotherapy between two groups of 139 patients with advanced CCA.

RESULTS

Differential genetic alterations between the MSI-H and MSS groups included mutations in ARID1A, ACVR2A, TGFBR2, KMT2D, RNF43, and PBRM1 which were enriched in MSI-H groups. Patients with an MSI-H status have a significantly higher tumor mutation burden (TMB) (median 41.7 vs. 3.1 muts/Mb, P < 0.001) and more positive programmed death ligand 1 (PD-L1) expression (37.5% vs. 11.9%, P < 0.001) than those with an MSS status. Among patients receiving PD-1 inhibitor-based therapy, those with MSI-H had a longer median overall survival (OS, hazard ratio (HR) = 0.17, P = 0.001) and progression-free survival (PFS, HR = 0.14, P < 0.001) than patients with MSS. Integrating MSI-H and PD-L1 expression status (combined positive score ≥ 5) could distinguish the efficacy of immunotherapy.

CONCLUSIONS

MSI-H status was associated with a higher TMB value and more positive PD-L1 expression in CCA tumors. Moreover, in patients with advanced CCA who received PD-1 inhibitor-based immunotherapy, MSI-H and positive PD-L1 expression were associated with improved both OS and PFS.

TRIAL REGISTRATION

This study was registered on ClinicalTrials.gov on 07/01/2017 (NCT03892577).

Potential Predictive Immune and Metabolic Biomarkers of Tumor Microenvironment Regarding Pathological and Clinical Response in Esophageal Cancer After Neoadjuvant Chemoradiotherapy: A Systematic Review

INTRODUCTION

The tumor microenvironment (TME) plays a crucial role in therapy response and modulation of immunologic surveillance. Adjuvant immunotherapy has recently been introduced in post-surgery treatment of locally advanced esophageal cancer (EC) with residual pathological disease after neoadjuvant chemoradiotherapy (nCRT). F-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) remains a valuable imaging tool to assess therapy response and to visualize metabolic TME; however, there is still a paucity in understanding the interaction between the TME and nCRT response. This systematic review investigated the potential of TME biomarkers and 18F-FDG-PET/CT features to predict pathological and clinical response (CR) after nCRT in EC.

METHODS

A literature search of the Medline and Embase electronic databases identified 4190 studies. Studies regarding immune and metabolic TME biomarkers and 18F-FDG-PET/CT features were included for predicting pathological response (PR) and/or CR after nCRT. Separate analyses were performed for 18F-FDG-PET/CT markers and these TME biomarkers.

RESULTS

The final analysis included 21 studies-10 about immune and metabolic markers alone and 11 with additional 18F-FDG-PET/CT features. High CD8 infiltration before and after nCRT, and CD3 and CD4 infiltration after nCRT, generally correlated with better PR. A high expression of tumoral or stromal programmed death-ligand 1 (PD-L1) after nCRT was generally associated with poor PR. Moreover, total lesion glycolysis (TLG) and metabolic tumor volume (MTV) of the primary tumor were potentially predictive for clinical and PR.

CONCLUSION

CD8, CD4, CD3, and PD-L1 are promising immune markers in predicting PR, whereas TLG and MTV are potential 18F-FDG-PET/CT features to predict clinical and PR after nCRT in EC.

A Clinical Viewpoint on the Use of Targeted Therapy in Advanced Gastric Cancer

The development of therapies for advanced gastric cancer (GC) has made significant progress over the past few years. The identification of new molecules and molecular targets is expanding our understanding of the disease's intricate nature. The end of the classical oncology era, which relied on well-studied chemotherapeutic agents, is giving rise to novel and unexplored challenges, which will cause a significant transformation of the current oncological knowledge in the next few years. The integration of established clinically effective regimens in additional studies will be crucial in managing these innovative aspects of GC. This study aims to present an in-depth and comprehensive review of the clinical advancements in targeted therapy and immunotherapy for advanced GC.

Evaluating mismatch repair deficiency in colorectal cancer biopsy specimens

Mismatch repair (MMR) testing on all new cases of colorectal cancer (CRC) has customarily been preferably performed on surgical specimens, as more tissue is available; however, new clinical trials for the use of immune checkpoint inhibitors in the neoadjuvant setting require MMR testing on biopsy samples. This study aims at identifying advantages, disadvantages and any potential pitfalls in MMR evaluation on biopsy tissue and how to cope with them. The study is prospective-retrospective, recruiting 141 biopsies (86 proficient (p)MMR and 55 deficient (d)MMR) and 97 paired surgical specimens (48 pMMR; 49 dMMR). In biopsy specimens, a high number of indeterminate stains was observed, in particular for MLH1 (31 cases, 56.4%). The main reasons were a punctate nuclear expression of MLH1, relatively weak MLH1 nuclear expression compared to internal controls, or both (making MLH1 loss difficult to interpret), which was solved by reducing primary incubation times for MLH1. A mean of  ≥ 5 biopsies had adequate immunostains, compared to ≤ 3 biopsies in inadequate cases. Conversely, surgical specimens rarely suffered from indeterminate reactions, while weaker staining intensity (p < 0.007) for MLH1 and PMS2 and increased patchiness grade (p < 0.0001) were seen. Central artefacts were almost exclusive to surgical specimens. MMR status classification was possible in 92/97 matched biopsy/resection specimen cases, and all of these were concordant (47 pMMR and 45 dMMR). Evaluation of MMR status on CRC biopsy samples is feasible, if pitfalls in interpretation are known, making laboratory-specific appropriate staining protocols fundamental for high-quality diagnoses.

PD-L1 Expression in Cutaneous Angiosarcomas: A Systematic Review with Meta-Analysis

Cutaneous angiosarcoma (CAS) is the most common type of angiosarcoma that predominantly affects older Caucasians. The outcomes of immunotherapy in CAS are currently under investigation in relation to the expression of programmed death ligand 1 (PD-L1) and other biomarkers. We performed a systematic review and metanalysis of data from the current literature reporting on PD-L1 immunohistochemistry expression. A systematic search of publications in the electronic databases PubMed, Web of Science, and Scopus was conducted using the following terms: "PD-L1" and "angiosarcomas". A total of ten studies reporting on 279 cases were identified and included in the meta-analysis. The pooled prevalence of PD-L1 expression in CAS was 54% (95% CI 36-71%), with high heterogeneity (I² = 84.81%, p < 0.001). In sub-group analysis, the proportion of PD-L1 expression in CAS was significantly (p = 0.049) lower in Asian studies (ES = 35%, 95% CI 28-42%, I² = 0.0%, p = 0.46) than in European studies (ES = 71%, 95% CI 51-89%, I² = 48.91%, p = 0.12).

A practical approach for PD-L1 evaluation in gastroesophageal cancer

PD-L1 is an established predictive immunohistochemical biomarker of response to immune checkpoint inhibitors. At present, PD-L1 is routinely assessed on biopsy samples of advanced gastroesophageal cancer patients before initiating first-line treatment. However, PD-L1 is still a suboptimal biomarker, due to changing cut-off values and scoring systems, interobserver and interlaboratory variability.

This practical illustrated review discusses the range of staining patterns of PD-L1 and the potential pitfalls and challenges that can be encountered when evaluating PD-L1, focusing on gastric and gastroesophageal adenocarcinoma (G/GEA) and esophageal squamous cell carcinoma (ESCC).

Extensive molecular profiling of squamous cell anal carcinoma in a phase 2 trial population: Translational analyses of the "CARACAS" study

BACKGROUND

Molecular characteristics of squamous cell anal carcinoma (SCAC) are poorly explored. Immune checkpoint inhibitors showed limited activity in phase I/II trials, but predictive and prognostic biomarkers are lacking.

PATIENTS AND METHODS

In the phase II randomised trial CARACAS (NCT03944252), avelumab alone (Arm A) or with cetuximab (Arm B) was tested in pre-treated advanced SCAC , with overall response rate being the primary end-point. On pre-treatment tumour tissue samples, we assessed Human papillomavirus status, programmed-death ligand 1 (PD-L1) expression, mismatch repair proteins expression, tumour mutational burden (TMB) and comprehensive genomic profiling by FoundationOne CDx. Tumour-infiltrating lymphocytes were characterised on haematoxylin-eosine-stained samples. Primary objective was to describe response to immunotherapy in the CARACAS trial population according to molecular and histological characteristics. Secondary objectives were to assess progression-free survival (PFS) and overall survival (OS) according to molecular biomarkers.

RESULTS

High PD-L1 (>40 with combined positive score) was significantly more frequent in patients with disease control (p = 0.0109). High TMB (>10 mutations per megabase) was related to better OS (hazard ratio (HR) = 0.09; 95%confidence interval (CI) 0.01-0.68; p = 0.019) and PFS (HR = 0.44; 95%CI = 0.15-1.27; p = 0.129). High expression of PD-L1 conferred longer OS (HR = 0.46; 95%CI = 0.19-1.08; p = 0.075) and PFS (HR = 0.42; 95%CI = 0.20-0.92; p = 0.03). Neither OS (HR = 1.30; 95%CI = 0.72-2.36; p = 0.39) or PFS (HR = 1.31; 95%CI = 0.74-2.31; p = 0.357) was affected by high (>1.2) Tumour-infiltrating lymphocytes count. High TMB and PD-L1identified patients were with significantly better OS (HR = 0.33; 95%CI = 0.13-0.81; p = 0.015) and PFS (HR = 0.48; 95%CI = 0.23-1.00; p = 0.015).

CONCLUSIONS

To our knowledge, TranslaCARACAS is the first study to document prognostic role of TMB and PD-L1 in advanced SCAC patients treated with immune checkpoint inhibitors.

Tumors of the Digestive System: Comprehensive Review of Ancillary Testing and Biomarkers in the Era of Precision Medicine

Immunotherapy has remained at the vanguard of promising cancer therapeutic regimens due to its exceptionally high specificity for tumor cells and potential for significantly improved treatment-associated quality of life compared to other therapeutic approaches such as surgery and chemoradiation. This is especially true in the digestive system, where high rates of mutation give rise to a host of targetable tumor-specific antigens. Many patients, however, do not exhibit measurable improvements under immunotherapy due to intrinsic or acquired resistance, making predictive biomarkers necessary to determine which patients will benefit from this line of treatment. Many of these biomarkers are assessed empirically by pathologists according to nuanced scoring criteria and algorithms. This review serves to inform clinicians and pathologists of extant and promising upcoming biomarkers predictive of immunotherapeutic efficacy among digestive system malignancies and the ancillary testing required for interpretation by pathologists according to tumor site of origin.

Current Treatment of Potentially Resectable Pancreatic Ductal Adenocarcinoma: A Medical Oncologist's Perspective

Pancreatic cancer has traditionally been associated with a dismal prognosis, even in early stages of the disease. In recent years, the introduction of newer generation chemotherapy regimens in the adjuvant setting has improved the survival of patients treated with upfront resection. However, there are multiple theoretical advantages to deliver early systemic therapy in patients with localized pancreatic cancer. So far, the evidence supports the use of neoadjuvant therapy for patients with borderline resectable pancreatic cancer. The benefit of this treatment sequence for patients with resectable disease remains elusive. In this review, we summarize the data on adjuvant therapy for pancreatic cancer and describe which evidence backs the use of neoadjuvant therapy. Additionally, we address important issues faced in clinical practice when treating patients with localized pancreatic cancer.