Advanced, recurrent, and persistent cervical cancer management: in the era of immunotherapy.

Cervical cancer constitutes a significant health burden for women worldwide despite being preventable by vaccination and screening. Advanced stages of the disease are associated with a poor prognosis, and treatment approaches have seen little change over several decades, resulting in an overall survival rate of no more than 17 months. Additionally, there are limited options for second-line treatment. The urgent need for innovative and effective therapies to improve the outlook for this group of patients, along with an enhanced understanding of the interactions between the disease and the host's immune system, has propelled immunotherapy into a rapidly advancing field with notable achievements. Among various immunotherapeutic approaches, immune checkpoint inhibitors emerge as the most advanced treatment option. Clinical trials assessing these inhibitors as single agents or in combination with chemotherapy show promising results. As immunotherapy begins to redefine standards of care for metastatic, recurrent, or persistent cervical cancer, this review addresses recent advances and current recommendations for its management in both first and second-line treatment. The goal is to provide insights into the evolving landscape of cervical cancer treatment, specifically focusing on immunotherapeutic interventions.

The Emerging Role of Immune Checkpoint Blockade for the Treatment of Lung Cancer Brain Metastases.

Lung cancer has the highest incidence of brain metastases (BM) among solid organ cancers. Traditionally whole brain radiation therapy has been utilized for non-small-cell lung cancer (NSCLC) BM treatment, although stereotactic radiosurgery has emerged as the superior treatment modality for most patients. Highly penetrant central nervous system (CNS) tyrosine kinase inhibitors have also shown significant CNS activity in patients harboring select oncogenic drivers. There is emerging evidence that patients without oncogene-driven tumors derive benefit from the use of immune checkpoint inhibitors (ICIs). The CNS activity of ICIs have not been well studied given exclusion of patients with active BM from landmark trials, due to concerns of inadequate CNS penetration and activity. However, studies have challenged the idea of an immune-privileged CNS, given the presence of functional lymphatic drainage within the CNS and destruction of the blood brain barrier by BM. An emerging understanding of the interactions between tumor and CNS immune cells in the BM tumor microenvironment also support a role for immunotherapy in BM treatment. In addition, posthoc analyses of major trials have shown improved intracranial response and survival benefit of regimens with ICIs over chemotherapy (CT) alone for patients with BM. Two prospective phase 2 trials evaluating pembrolizumab monotherapy and atezolizumab plus CT in patients with untreated NSCLC BM also demonstrated significant intracranial responses. This review describes the interplay between CNS immune cells and tumor cells, discusses current evidence for ICI CNS activity from retrospective and prospective studies, and speculates on future directions of investigation.

Targeted Therapy Innovations for Melanoma.

Melanoma, a malignant tumor of melanocytes, poses a significant clinical challenge due to its aggressive nature and high potential for metastasis. The advent of targeted therapy has revolutionized the treatment landscape of melanoma, particularly for tumors harboring specific genetic alterations such as BRAF V600E mutations. Despite the initial success of targeted agents, resistance inevitably arises, underscoring the need for novel therapeutic strategies. This review explores the latest advances in targeted therapy for melanoma, focusing on new molecular targets, combination therapies, and strategies to overcome resistance.

Clinical characteristics and prognosis of pancreatitis associated with immune checkpoint inhibitors.

BACKGROUND AND OBJECTIVE: Immune checkpoint inhibitors (ICIs) have shown remarkable efficacy against various cancers in clinical practice. However, ICIs can cause immune checkpoint inhibitor-associated pancreatic injury, often leading to drug withdrawal, and then patients must go to specialized treatment. The patients, their primary tumors are sensitive to ICIs therapy, may experience treatment delays due to such adverse reactions. Therefore, there is a need for systematic clinical researches on immune-related pancreatic toxicity to provide a clinical basis for its prevention and treatment. METHODS: This study involved the collection of data from patients treated with ICIs and addressed pancreatic injury with preemptive treatment before continuing ICIs therapy. Then, we also statistically analyzed the incidence of pancreatic injury in patients with different courses and combined treatment, and the success rate of rechallenge treatment. RESULTS: The study included 62 patients, with 33.9% (21/62) experiencing varying degrees of pancreatic injury. Patients with pancreatic injury, 10 cases evolved into pancreatitis, representing 47.6% (10/21) in the pancreatic injury subgroup and 16.1% (10/62) of the total patient cohort. Preemptive treatment was administered to 47.6% (10/21) of patients with pancreatitis, the effective rate was 100%. Among these patients, 70% (7/10) underwent successful rechallenge with ICIs. The occurrence of pancreatic injury was positively correlated with the treatment duration (P < 0.05) but showed no significant correlation with combination therapies (P > 0.05). CONCLUSION: The likelihood of pancreatic injury increased with longer treatment durations with ICIs; no significant association was found between the incidence of ICIs-related pancreatic damage and combination therapies. Preemptive treatment for immune-related pancreatitis is feasible, allowing some patients to successfully undergo rechallenge with ICIs therapy.

The evolving role of immune checkpoint inhibitors in cervical and endometrial cancer.

The introduction of immune checkpoint inhibitors (ICIs) has revolutionized the treatment landscape for numerous tumor types, including cervical and endometrial cancers. Multiple ICIs against programmed cell death-1 (PD-1), programmed death-ligand 1 (PD-L1), and cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) have demonstrated encouraging outcomes in controlled clinical studies for advanced cervical and endometrial cancers. For advanced cervical cancer, approved ICIs as second-line treatment include cemiplimab, nivolumab, and pembrolizumab as single agents. In the first-line treatment setting, options include pembrolizumab alone or in combination with bevacizumab, as well as atezolizumab combined with a backbone platinum-based chemotherapy plus bevacizumab. Additionally, for locally advanced cervical cancer, pembrolizumab is recommended alongside concurrent chemoradiotherapy. For endometrial cancer, pembrolizumab monotherapy, pembrolizumab in combination with lenvatinib, and dostarlimab are currently approved as second-line treatment options. Moreover, either dostarlimab or pembrolizumab can be added to first-line platinum-based chemotherapy for mismatch repair deficient malignancies. Although the inclusion of these agents in clinical practice has led to improved overall response rates and survival outcomes, many patients still lack benefits, possibly due to multiple intrinsic and adaptive resistance mechanisms to immunotherapy. This review aims to highlight the rationale for utilizing ICIs and their current role, while also delineating the proposed mechanisms of resistance to ICIs in cervical and endometrial cancer.

Immune checkpoint expression as prognostic biomarker candidates in non-small cell lung carcinoma patients.

BACKGROUND: Cancer immunotherapy has had an important role in oncologic therapeutics for patients with non-small cell lung cancer (NSCLC) using checkpoint inhibitors. We will explore the possible prognosis biomarker candidates such as: soluble OX40 (sOX40), OX40L (sOX40L), Glucocorticoid-induced tumor necrosis factor receptor family-related receptor (GITR), and their ligand (GITRL), 4-1BB or tumor necrosis factor receptor superfamily 9 (TNFRS9) and inducible T cell co-stimulator (ICOS) in peripheral blood of NSCLC patients. METHODS: Fifty-eight patients were diagnosed with advanced NSCLC between January 2019 and March 2020. RESULTS: High sOX40 and low s4-1BB levels in smokers compared non-smoker NSCLC patients. Lower sOX40L levels were found in the male than female (p < 0.05). High sOX40 and sGITRL in stage III compared to the stage IV (p < 0.05). With follow-up at 21.4 months, 44.1% and 91.1% were alive in the sGITRhigh and sGITRlow groups, respectively (p = 0.02), and 73.3% and 27.7% were alive in the sGITRLhigh and sGITRLlow groups, respectively (p = 0.02). At 22 months, 38.7% and 92.3% were alive in the sOX40Lhigh and sOX40Llow groups, respectively (p = 0.01). CONCLUSION: sGITR, sGITRL, and sOX40L levels were potential prognostic biomarkers and could have an important role as new targets of immunotherapy in NSCLC patients. sGITR, sGITRL, sOX40L, and sOX40 levels were associated with smoking, sex, stage, and age in NSCLC.

Effects of antibiotics on the anti-tumor efficacy of immune checkpoint inhibitor therapy.

PURPOSE: Immunotherapy using immune checkpoint inhibitors (ICIs) has shown several benefits over traditional therapies. However, the eligible population remains small. Antibiotic (ATB) use might reduce immunotherapy efficacy by disrupting the gut microbiota. However, in China, ATB effect on ICI therapy efficacy remains unelucidated. We aimed to assess the effects of ATBs on the anti-tumor efficacy of ICIs to provide a reference for clinical use. METHODS: We included 134 patients with advanced tumors undergoing ICI therapy at Shanghai Jiading District Central Hospital from January 1, 2021, to October 1, 2023. They were divided into Non-ATB and ATB groups based on ATB use within 30 days before and after ICI administration. Moreover, we compared progression-free (PFS) and overall (OS) survival between the groups. RESULTS: Median PFS and OS were lower in the ATB than in the Non-ATB group (PFS: 4.0 vs. 5.5 months; OS: 5.4 vs. 6.5 months). Univariate analysis revealed that ATB use significantly affected PFS (hazard ratio [HR] = 2.318, 95% confidence interval [CI] = 1.281-4.194, P = 0.005) and OS (HR = 2.115, 95% CI = 1.161-3.850, P = 0.014). Moreover, multivariate analysis revealed poor PFS (HR = 2.573, 95% CI = 1.373-4.826, P = 0.003) and OS (HR = 2.452, 95% CI = 1.298-4.632, P = 0.006) in patients who received ATBs during ICI therapy. CONCLUSIONS: ATB use is negatively correlated with ICI therapy efficacy, leading to reduced PFS and OS in patients undergoing such treatment. Owing to the significant impact of ATBs on the human gut microbiome, regulation of the gut microbiome may emerge as a novel therapeutic target that can enhance the clinical activity of ICIs.

Sicca syndrome/Sjögren's disease associated with cancer immunotherapy: a narrative review on clinical presentation, biomarkers, and management.

INTRODUCTION: Almost one-quarter of immune checkpoint inhibitor (ICI) recipients experience sicca syndrome, while Sjögren's disease (SjD) is estimated at 0.3-2.5%, possibly underreported. AREAS COVERED: This narrative review (Medline/Embase until January/31/2024) addresses the pathophysiology, incidence, demographic/clinical features, biomarkers, labial salivary gland biopsy (LSGB), fulfillment of the idiopathic SjD (iSjD) classificatory criteria, differential diagnosis, and management of sicca syndrome/SjD associated with ICIs. EXPERT OPINION: SjD associated with ICIs is underdiagnosed, since studies that performed the mandatory SjD investigation identified that 40-60% of patients with sicca syndrome associated with ICIs meet the iSjD classificatory criteria. LSGB played a fundamental role in recognizing these cases, as most of them had negative anti-Ro/SS-A antibody. Despite the finding of focal lymphocytic sialoadenitis in LSGB samples mimicking iSjD, immunohistochemical analysis provided novel evidence of a distinct pattern for sicca syndrome/SjD associated with ICIs compared to iSjD. The former has scarcity of B lymphocytes, which are a hallmark of iSjD. Additionally, patients with sicca syndrome/SjD associated with ICIs have demographical/clinical/serological and treatment response dissimilarities compared to iSjD. Dryness symptoms are more acute in the former than in iSjD, with predominance of xerostomia over xerophthalmia, and partial/complete response to glucocorticoids. Dryness symptoms in ICI-treated patients warrant prompt SjD investigation.

Takotsubo syndrome as an outcome of the use of checkpoint inhibitor therapy in patients with COVID-19.

Takotsubo Syndrome (TS) is a heart disease caused by extreme exposure of the body to physical or psychological stress. In the context of COVID-19, the virus can be a significant source of stress, with particular attention being paid to the cytokine storm as a cause of damage to the body. New research shows that the production of specific cytokines is linked to the activation of immune checkpoint proteins such as PD-1, PD-L1, and CTLA-4 on T cells. Although initially beneficial in combating infections, it can suppress defense and aid in disease progression. Therefore, checkpoint inhibitor therapy has been highlighted beyond oncological therapies, given its effectiveness in strengthening the immune system. However, this treatment can lead to excessive immune responses, inflammation, and stress on the heart, which can cause Takotsubo Syndrome in patients. Several studies investigate the direct link between this therapy and cardiac injuries in these patients, which can trigger TS. From this perspective, we must delve deeper into this treatment and consider its effects on the prognosis against SARS-CoV-2 infection.

Predictors of response to immunotherapy in colorectal cancer.

Colorectal cancer (CRC) is a major cause of cancer-related deaths globally. While treatment advancements have improved survival rates, primarily through targeted therapies based on KRAS, NRAS, and BRAF mutations, personalized treatment strategies for CRC remain limited. Immunotherapy, mainly immune checkpoint blockade, has shown efficacy in various cancers but is effective in only a small subset of patients with CRC with deficient mismatch repair (dMMR) proteins or high microsatellite instability (MSI). Recent research has challenged the notion that CRC is immunologically inert, revealing subsets with high immunogenicity and diverse lymphocytic infiltration. Identifying precise biomarkers beyond dMMR and MSI is crucial to expanding immunotherapy benefits. Hence, exploration has extended to various biomarker sources, such as the tumor microenvironment, genomic markers, and gut microbiota. Recent studies have introduced a novel classification system, consensus molecular subtypes, that aids in identifying patients with CRC with an immunogenic profile. These findings underscore the necessity of moving beyond single biomarkers and toward a comprehensive understanding of the immunological landscape in CRC, facilitating the development of more effective, personalized therapies.

Oral and cutaneous immune-related adverse events in cancer patients: Prevalence and overall survival.

OBJECTIVES: To assess the prevalence of cutaneous and oral immune-related adverse events (irAEs) in cancer patients, risk factors for its development, and overall survival (OS). MATERIALS AND METHODS: This retrospective observational study which included 748 medical records of cancer patients who received immune checkpoint inhibitors (ICIs). Demographic and clinicopathological characteristics were collected and analyzed. RESULTS: Most patients were male (59.4%), with stage IV cancer (65%) and received pembrolizumab (46.7%). Four hundred fourteen (55.34%) patients developed cutaneous lesions, 84 (11.2%) developed oral mucosal lesions, and 70 (9.3%) developed xerostomia. The median time for irAEs development was 11 weeks for cutaneous and oral mucosal lesions, and 21.5 weeks for xerostomia. Patients who received PD-1 + CTLA-4 had a higher risk for developing cutaneous irAEs (p = 0.001), while those who underwent ICI and concurrent chemotherapy had a higher risk (p = 0.008) for developing oral mucosal lesions. Patients who presented oral and cutaneous irAEs had better OS than those who did not present (p = 0.0001). CONCLUSION: Cutaneous effects affected more than half of the patients, while oral effects and xerostomia were found in around 11% and 9% of patients, respectively. Concurrent chemotherapy and PD-1 + CTLA-4 were more associated with oral and cutaneous irAEs, respectively. Patients who developed such irAEs had better overall survival.

Acute kidney injury associated with anti-PD-1 and anti-PD-L1 drugs: a meta-analysis of randomized clinical trials.

BACKGROUND: Immune Checkpoint Inhibitors (ICI) have been widely used in treating different types of cancer. They increase survival in many oncologic patients and enable cancer-specific therapy. Acute Kidney Injury (AKI) is one of the adverse effects associated with using ICI, where knowledge of the prevalence and renal histological findings are still reasons for discussion. OBJECTIVE: Therefore, this meta-analysis evaluates the association between ICI use and AKI. METHODS: The search was performed in PubMed, Lilacs, and Cochrane platforms. Studies published up to December 1, 2022, were included. RESULTS: A total of 16 studies met the established PICOT criteria and were included in this review. Comparing the ICI plus chemotherapy against chemotherapy alone, the relative risk (RR) for AKI's development with ICI use was 2.89 (95%CI 1.37-6.10). In the analyses by class and drug type, programmed cell death 1 monoclonal antibody (anti-PD-1) showed an increased risk of 2.11 (95%CI 1.26-3.52), and pembrolizumab demonstrated a risk of AKI (RR= 2.77, 95%CI 1.46-5.26). Likewise, regarding the severity of AKI, AKI grade 3 or higher was more common in the ICI plus chemotherapy compared to the chemotherapy group: 3.66 (95%CI 1.19-11.30), while the subgroup analyses pooled studies comparing ICI alone versus chemotherapy alone in the control group did not demonstrate an association with AKI. CONCLUSIONS: These findings suggest that ICI use is associated with an increased risk of AKI and that anti-PD-1 use is associated with a higher incidence of renal adverse events than programmed cell death ligand 1 monoclonal antibody (anti-PD-L1). Studies with adequate power and well-defined criteria for acute interstitial nephritis, nowadays taken as a synonym for AKI related to ICI, are necessary.

The Role of αvß3 Integrin in Cancer Therapy Resistance.

A relevant challenge for the treatment of patients with neoplasia is the development of resistance to chemo-, immune-, and radiotherapies. Although the causes of therapy resistance are poorly understood, evidence suggests it relies on compensatory mechanisms that cells develop to replace specific intracellular signaling that should be inactive after pharmacological inhibition. One such mechanism involves integrins, membrane receptors that connect cells to the extracellular matrix and have a crucial role in cell migration. The blockage of one specific type of integrin is frequently compensated by the overexpression of another integrin dimer, generally supporting cell adhesion and migration. In particular, integrin αvß3 is a key receptor involved in tumor resistance to treatments with tyrosine kinase inhibitors, immune checkpoint inhibitors, and radiotherapy; however, the specific inhibition of the αvß3 integrin is not enough to avoid tumor relapse. Here, we review the role of integrin αvß3 in tumor resistance to therapy and the mechanisms that have been proposed thus far. Despite our focus on the αvß3 integrin, it is important to note that other integrins have also been implicated in drug resistance and that the collaborative action between these receptors should not be neglected.

Immune checkpoint inhibitors-associated thrombosis in patients with head and neck cancer: a study of the Spanish society of medical oncology (SEOM) thrombosis and cancer group.

PURPOSE: Both venous and arterial thrombotic events (VTE/AT) can be associated with Immune Checkpoint Inhibitors (ICI). However, there is a paucity of information apropos patients in routine clinical practice. METHODS: /Patients. This retrospective, multicenter study was promoted by the Thrombosis and Cancer Section of the Spanish Society of Medical Oncology (SEOM). Individuals with head and neck cancer who initiated ICI between 01/01/2015 and 31/12/2021 were recruited. Minimum follow-up was 6 months (except in cases of demise). The primary objective was to calculate the incidence of ICI-associated VTE/AT, with secondary objectives including the analysis of their impact on survival and the identification of variables predictive of VTE/AT. RESULTS: A total of 143 patients with head and neck cancer were enrolled. The incidence of VTE/AT during follow-up (median 8.6 months) was 2.8%. Survival analysis showed no significant differences (p = 0.644) between the group that developed VTE/AT (median 7.13 months, 95% CI 0-22.9) and the group that did not (median 9.86 months, 95% CI 6.3-13.4). The presence of liver metastases was predictive of VTE/AT (p < 0.05). CONCLUSIONS: Thromboembolic disease associated with immunotherapy in patients with head and neck neoplasia does not significantly impact survival. The presence of liver metastases can predict these events.

Safety and efficacy of restarting immune checkpoint inhibitors in non-small cell lung cancer patients following immune-related adverse events: a systematic review and meta-analysis.

OBJECTIVE: This meta-analysis aims to evaluate the safety and efficacy of restarting immune checkpoint inhibitors (ICIs) in patients with non-small cell lung cancer (NSCLC) after experiencing immune-related adverse events (irAEs). METHODS: A comprehensive search of PubMed, Web of Science, Embase, and the Cochrane Library was conducted to identify studies investigating the safety and efficacy of restarting ICIs in NSCLC patients after irAEs. Outcome measures, including objective response rate (ORR), progression-free survival (PFS), and overall survival (OS) after ICI restarting, were extracted. Meta-analysis was performed using the R meta-package. RESULTS: Four studies involving a total of 326 subjects were included, comprising 137 patients who restarted ICI treatment after irAEs and 189 patients who did not restart ICI treatment. The results revealed that ICI restarting was associated with an increased ORR (OR = 2.36, 95% CI 1.49-3.84), prolonged PFS (HR = 0.60, 95% CI 0.42-0.86), and prolonged OS (HR = 0.65, 95% CI 0.43-0.99) compared to non-restarting. The incidence of irAEs after ICI restarting was 45% (95% CI 0.27-0.63). CONCLUSION: Restarting ICI treatment after discontinuation due to previous irAEs appears to be a reasonable option for NSCLC patients. However, a comprehensive assessment of the potential benefits and risks to individual patients is crucial, and close monitoring of irAEs is warranted.

Development and validation of a nomogram to predicting the efficacy of PD-1/PD-L1 inhibitors in patients with nasopharyngeal carcinoma.

PURPOSE: With the treatment of nasopharyngeal carcinoma (NPC) by PD-1/PD-L1 inhibitors used widely in clinic, it becomes very necessary to anticipate whether patients would benefit from it. We aimed to develop a nomogram to evaluate the efficacy of anti-PD-1/PD-L1 in NPC patients. METHODS: Totally 160 NPC patients were enrolled in the study. Patients were measured before the first PD-1/PD-L1 inhibitors treatment and after 8-12 weeks of immunotherapy by radiological examinations to estimate the effect. The least absolute shrinkage and selection operator (LASSO) logistic regression was used to screen hematological markers and establish a predictive model. The nomogram was internally validated by bootstrap resampling and externally validated. Performance of the model was evaluated using concordance index, calibration curve, decision curve analysis and receiver operation characteristic curve. RESULTS: Patients involved were randomly split into training cohort ang validation cohort. Based on Lasso logistic regression, systemic immune-inflammation index (SII) and ALT to AST ratio (LSR) were selected to establish a predictive model. The C-index of training cohort and validating cohort was 0.745 and 0.760. The calibration curves and decision curves showed the precise predictive ability of this nomogram. The benefit of the model showed in decision curve was better than TNM stage. The area under the curve (AUC) value of training cohort and validation cohort was 0.745 and 0.878, respectively. CONCLUSION: The predictive model helped evaluating efficacy with high accuracy in NPC patients treated with PD-1/PD-L1 inhibitors.

Investigating the Role of SNAI1 and ZEB1 Expression in Prostate Cancer Progression and Immune Modulation of the Tumor Microenvironment.

Prostate cancer (PCa) is an immunologically cold tumor and the molecular processes that underlie this behavior are poorly understood. In this study, we investigated a primary cohort of intermediate-risk PCa (n = 51) using two NanoString profiling panels designed to study cancer progression and immune response. We identified differentially expressed genes (DEGs) and pathways associated with biochemical recurrence (BCR) and clinical risk. Confirmatory analysis was performed using the TCGA-PRAD cohort. Noteworthy DEGs included collagens such as COL1A1, COL1A2, and COL3A1. Changes in the distribution of collagens may influence the immune activity in the tumor microenvironment (TME). In addition, immune-related DEGs such as THY1, IRF5, and HLA-DRA were also identified. Enrichment analysis highlighted pathways such as those associated with angiogenesis, TGF-beta, UV response, and EMT. Among the 39 significant DEGs, 11 (28%) were identified as EMT target genes for ZEB1 using the Harmonizome database. Elevated ZEB1 expression correlated with reduced BCR risk. Immune landscape analysis revealed that ZEB1 was associated with increased immunosuppressive cell types in the TME, such as naïve B cells and M2 macrophages. Increased expression of both ZEB1 and SNAI1 was associated with elevated immune checkpoint expression. In the future, modulation of EMT could be beneficial for overcoming immunotherapy resistance in a cold tumor, such as PCa.

PD-L1 expression and microsatellite instability (MSI) in cancer of unknown primary site.

BACKGROUND: Cancer of unknown primary site (CUP) is a heterogeneous group of tumors for which the origin remains unknown. Clinical outcomes might be influenced by regulatory processes in its microenvironment. Microsatellite instability (MSI) is a predictive biomarker for cancer immunotherapy and its status, as well as co-occurrence with PD-L1 expression, is poorly evaluated. We aim to evaluate the expression of PD-L1 and the status of MSI in CUP and their possible associations with clinical-pathological features. METHODS: The combined positive score (CPS) PD-L1 expression was evaluated by immunohistochemistry. MSI status was assessed using a hexa-plex marker panel by polymerase chain reaction followed by fragment analysis. RESULTS: Among the 166 cases, MSI analysis was conclusive in 120, with two cases being MSI positive (1.6%). PD-L1 expression was positive in 18.3% of 109 feasible cases. PD-L1 expression was significantly associated with non-visceral metastasis and a dominance of nodal metastasis. The median overall survival (mOS) was 3.7 (95% CI 1.6-5.8) months and patients who expressed PD-L1 achieved a better mOS compared to those who did not express PD-L1 (18.7 versus 3.0 months, p-value: < .001). ECOG-PS equal to or more than two and PD-L1 expression were independent prognostic factors in multivariate analysis (2.37 and 0.42, respectively). CONCLUSION: PD-L1 is expressed in a subset (1/5) of patients with CUP and associated with improved overall survival, while MSI is a rare event. There is a need to explore better the tumor microenvironment as well as the role of immunotherapy to change such a bad clinical outcome.