The Italian Rare Biliary tract Cancer initiative (IRaBiCa): A multicentric observational study of Gruppo Oncologico dell'Italia Meridionale (GOIM) in collaboration with Gruppo Italiano Colangiocarcinoma (GICO).

INTRODUCTION: About 90% of cholangiocarcinomas are adenocarcinomas with glandular or tubular structures lined by epithelial cells, with no bile production and with a variable degree of differentiation, arising in the background of desmoplastic stroma. The remaining 10% is represented by rarer histological variants of which there is little knowledge regarding the biological behavior, molecular characterization, and sensitivity to the various possible therapies, including molecular-based treatments. Such rare tumors are described only in case reports or small retrospective series because of their exclusion from clinical trials. This national initiative, here presented, aims to address the following knowledge gap: a) how much does histological diversity translate into clinical manifestation variety? b) are those chemotherapy regimens, recommended for conventional biliary tract cancers, potentially active in rare variants?Therefore, epidemiological, pathological, and clinical characterization of series of rare biliary histotypes/variants, for which therapeutic and follow-up data are available, will be collected. METHODS: An Italian task force on rare tumors of the biliary tract (IRaBiCa) has been created, whose initiative is a multicenter retrospective study involving 34 Italian cancer centers.Clinical data from approximately 100 patients will be collected and analyzed. Continuous variables will be presented as median ± standard deviation, while categorical variables will be expressed in terms of frequency. Kaplan-Maier analyses will be used to compare disease free, progression free and overall survival, according to the different histotypes. CONCLUSIONS: We expect to gather novel data on rare histotypes of biliary tract cancer that will be useful to support their molecular and immunological characterization.

Clinical relevance of exosome-derived microRNAs in Ovarian Cancer: Looking for new tumor biological fingerprints.

Specific tumor-derived extracellular vesicles, called exosomes, are considered as potential key players in cross-talk between immune system and tumor microenvironment in several solid tumors. Different studies highlighted the clinical relevance of exosomes in ovarian cancer (OC) for their role in early diagnosis, prognosis, chemoresistance, targeted therapy. The exosomes are nanosize vesicles carrying lipids, proteins, and nucleic acids. In particular, exosomes shuttle a wide spectrum of microRNAs (miRNAs) able to induce phenotypic reprogramming of target cells, contributing to tumor progression. In this review, we will discuss the promising role of miRNAs shuttled by exosomes, called exosomal miRNAs (exo-miRNAs), as potential biomarkers for early detection, tumour progression and metastasis, prognosis, and response to therapy in OC women, in order to search for new potential biological fingerprints able to better characterize the evolution of this malignancy and provide a clinically relevant non-invasive approach useful for adopting, in future, personalized therapeutic strategies.

Theranostic biomarkers and PARP-inhibitors effectiveness in patients with non-BRCA associated homologous recombination deficient tumors: Still looking through a dirty glass window?

Breast cancer susceptibility gene 1 (BRCA1) and breast cancer susceptibility gene 2 (BRCA2) deleterious variants were the first and, still today, the main biomarkers of poly(ADP)ribose polymerase (PARP)-inhibitors (PARPis) benefit. The recent, increased, numbers of individuals referred for counseling and multigene panel testing, and the remarkable expansion of approved PARPis, not restricted to BRCA1/BRCA2-Pathogenic Variants (PVs), produced a strong clinical need for non-BRCA biomarkers. Significant limitations of the current testing and assays exist. The different approaches that identify the causes of Homologous Recombination Deficiency (HRD), such as the germline and somatic Homologous Recombination Repair (HRR) gene PVs, the testing showing its consequences, such as the genomic scars, or the novel functional assays such as the RAD51 foci testing, are not interchangeable, and should not be considered as substitutes for each other in clinical practice for guiding use of PARPi in non-BRCA, HRD-associated tumors. Today, the deeper knowledge on the significant relationship among all proteins involved in the HRR, not limited to BRCA, expands the possibility of a successful non-BRCA, HRD-PARPi synthetic lethality and, at the same time, reinforces the need for enhanced definition of HRD biomarkers predicting the magnitude of PARPi benefit.

Potential agnostic role of BRCA alterations in patients with several solid tumors: One for all, all for one?

Germline BRCA1/2 alterations in the Homologous Recombination (HR) pathway are considered as main susceptibility biomarkers to Hereditary Breast and Ovarian Cancers (HBOC). The modern molecular biology technologies allowed to characterize germline and somatic BRCA1/2 alterations in several malignancies, broadening the landscape of BRCA1/2-alterated tumors. In the last years, BRCA genetic testing, beyond the preventive value, also assumed a predictive and prognostic significance for patient management. The approval of molecules with agnostic indication is leading to a new clinical model, defined "mutational". Among these drugs, the Poly (ADP)-Ribose Polymerase inhibitors (PARPi) for BRCA1/2-deficient tumors were widely studied leading to increasing therapeutic implications. In this Review we provided an overview of the main clinical studies describing the association between BRCA-mutated tumors and PARPi response, focusing on the controversial evidence about the potential agnostic indication based on BRCA1/2 alterations in several solid tumors.

Low plasma PD-L1 levels, early tumor onset and absence of peritoneal carcinomatosis improve prognosis of women with advanced high-grade serous ovarian cancer.

BACKGROUND: The most common subtype of ovarian cancer (OC) showing immunogenic potential is represented by the high-grade serous ovarian cancer (HGSOC), which is characterized by the presence of tumor-infiltrating immune cells able to modulate immune response. Because several studies showed a close correlation between OC patient's clinical outcome and expression of programmed cell death protein-1 or its ligand (PD-1/PD-L1), the aim of our study was to investigate if plasma levels of immunomodulatory proteins may predict prognosis of advanced HGSOC women. PATIENTS AND METHODS: Through specific ELISA tests, we analyzed plasma concentrations of PD-L1, PD-1, butyrophilin sub-family 3A/CD277 receptor (BTN3A1), pan-BTN3As, butyrophilin sub-family 2 member A1 (BTN2A1), and B- and T-lymphocyte attenuator (BTLA) in one hundred patients affected by advanced HGSOC, before surgery and therapy. The Kaplan-Meier method was used to generate the survival curves, while univariate and multivariate analysis were performed using Cox proportional hazard regression models. RESULTS: For each analyzed circulating biomarker, advanced HGSOC women were discriminated based on long (≥ 30 months) versus short progression-free survival (PFS < 30 months). The concentration cut-offs, obtained by receiver operating characteristic (ROC) analysis, allowed to observe that poor clinical outcome and median PFS ranging between 6 and 16 months were associated with higher baseline levels of PD-L1 (> 0.42 ng/mL), PD-1 (> 2.48 ng/mL), BTN3A1 (> 4.75 ng/mL), pan-BTN3As (> 13.06 ng/mL), BTN2A1 (> 5.59 ng/mL) and BTLA (> 2.78 ng/mL). Furthermore, a lower median PFS was associated with peritoneal carcinomatosis, age at diagnosis > 60 years or Body Mass Index (BMI) > 25. A multivariate analysis also suggested that plasma concentrations of PD-L1 ≤ 0.42 ng/mL (HR: 2.23; 95% CI: 1.34 to 3.73; p = 0.002), age at diagnosis ≤ 60 years (HR: 1.70; 95% CI: 1.07 to 2.70; p = 0.024) and absence of peritoneal carcinomatosis (HR: 1.87; 95% CI: 1.23 to 2.85; p = 0.003) were significant prognostic marker for a longer PFS in advanced HGSOC patients. CONCLUSIONS: The identification of high-risk HGSOC women could be improved through determination of the plasma PD-L1, PD-1, BTN3A1, pan-BTN3As, BTN2A1 and BTLA levels.

The Evolving Scenario in the Assessment of Radiological Response for Hepatocellular Carcinoma in the Era of Immunotherapy: Strengths and Weaknesses of Surrogate Endpoints.

Hepatocellular carcinoma (HCC) is a challenging malignancy characterised by clinical and biological heterogeneity, independent of the stage. Despite the application of surveillance programs, a substantial proportion of patients are diagnosed at advanced stages when curative treatments are no longer available. The landscape of systemic therapies has been rapidly growing over the last decade, and the advent of immune-checkpoint inhibitors (ICIs) has changed the paradigm of systemic treatments. The coexistence of the tumour with underlying cirrhosis exposes patients with HCC to competing events related to tumour progression and/or hepatic decompensation. Therefore, it is relevant to adopt proper clinical endpoints to assess the extent of treatment benefit. While overall survival (OS) is the most accepted endpoint for phase III randomised controlled trials (RCTs) and drug approval, it is affected by many limitations. To overcome these limits, several clinical and radiological outcomes have been used. For instance, progression-free survival (PFS) is a useful endpoint to evaluate the benefit of sequential treatments, since it is not influenced by post-progression treatments, unlike OS. Moreover, radiological endpoints such as time to progression (TTP) and objective response rate (ORR) are frequently adopted. Nevertheless, the surrogacy between these endpoints and OS in the setting of unresectable HCC (uHCC) remains uncertain. Since most of the surrogate endpoints are radiology-based (e.g., PFS, TTP, ORR), the use of standardised tools is crucial for the evaluation of radiological response. The optimal way to assess the radiological response has been widely debated, and many criteria have been proposed over the years. Furthermore, none of the criteria have been validated for immunotherapy in advanced HCC. The coexistence of the underlying chronic liver disease and the access to several lines of treatments highlight the urgent need to capture early clinical benefit and the need for standardised radiological criteria to assess cancer response when using ICIs in mono- or combination therapies. Here, we review the most commonly used clinical and radiological endpoints for trial design, as well as their surrogacy with OS. We also review the criteria for radiological response to treatments for HCC, analysing the major issues and the potential future perspectives.

Can circulating PD-1, PD-L1, BTN3A1, pan-BTN3As, BTN2A1 and BTLA levels enhance prognostic power of CA125 in patients with advanced high-grade serous ovarian cancer?

The most common subtype of ovarian cancer (OC) is the high-grade serous ovarian carcinoma (HGSOC), accounting for 70%-80% of all OC deaths. Although HGSOC is a potentially immunogenic tumor, clinical studies assessing the effectiveness of inhibitors of programmed death protein and its ligand (PD-1/PD-L1) in OC patients so far showed only response rates <15%. However, recent studies revealed an interesting prognostic role of plasma PD-1/PD-L1 and other circulating immunoregulatory molecules, such as the B- and T-lymphocyte attenuator (BTLA), butyrophilin sub-family 3A/CD277 receptors (BTN3A), and butyrophilin sub-family 2 member A1 (BTN2A1), in several solid tumors. Since evidence showed the prognostic relevance of pretreatment serum CA125 levels in OC, the aim of our study was to investigate if soluble forms of inhibitory immune checkpoints can enhance prognostic power of CA125 in advanced HGSOC women. Using specific ELISA tests, we examined the circulating PD-1, PD-L1, pan-BTN3As, BTN3A1, BTN2A1, and BTLA levels in 100 advanced HGSOC patients before treatment, correlating them with baseline serum CA125, age at diagnosis, body mass index (BMI), and peritoneal carcinomatosis. A multivariate analysis revealed that plasma BTN3A1 ≤4.75 ng/ml (HR, 1.94; 95% CI, 1.23-3.07; p=0.004), age at diagnosis ≤60 years (HR, 1.65; 95% CI, 1.05-2.59; p=0.03) and absence of peritoneal carcinomatosis (HR, 2.65; 95% CI, 1.66-4.22; p<0.0001) were independent prognostic factors for a longer progression-free survival (PFS) (≥30 months) in advanced HGSOC women. However, further two-factor multivariate analyses highlighted that baseline serum CA125 levels >401 U/ml and each soluble protein above respective concentration cutoff were covariates associated with shorter PFS (<30 months) and unfavorable clinical outcome, suggesting that contemporary measurement of both biomarkers than CA125 only could strengthen prognostic power of serum CA125 in predicting PFS of advanced HGSOC women. Plasma PD-L1, PD-1, BTN3A1, pan-sBTN3As, BTN2A1, or BTLA levels could be helpful biomarkers to increase prognostic value of CA125.

Prognostic and Predictive Role of Tumor-Infiltrating Lymphocytes (TILs) in Ovarian Cancer.

In the last decade, tumor-infiltrating lymphocytes (TILs) have been recognized as clinically relevant prognostic markers for improved survival, providing the immunological basis for the development of new therapeutic strategies and showing a significant prognostic and predictive role in several malignancies, including ovarian cancer (OC). In fact, many OCs show TILs whose typology and degree of infiltration have been shown to be strongly correlated with prognosis and survival. The OC histological subtype with the higher presence of TILs is the high-grade serous carcinoma (HGSC) followed by the endometrioid subtype, whereas mucinous and clear cell OCs seem to contain a lower percentage of TILs. The abundant presence of TILs in OC suggests an immunogenic potential for this tumor. Despite the high immunogenic potential, OC has been described as a highly immunosuppressive tumor with a high expression of PD1 by TILs. Although further studies are needed to better define their role in prognostic stratification and the therapeutic implication, intraepithelial TILs represent a relevant prognostic factor to take into account in OC. In this review, we will discuss the promising role of TILs as markers which are able to reflect the anticancer immune response, describing their potential capability to predict prognosis and therapy response in OC.

MUTYH-associated tumor syndrome: The other face of MAP.

MUTYH gene is involved in the base excision repair (BER) mechanism and its pathogenic alterations are associated with colorectal polyposis and cancer. MUTYH-associated polyposis (MAP) is a condition which is inherited in an autosomal recessive manner. MAP patients, beyond colorectal cancer (CRC), may develop other types of tumors, including duodenal, breast, ovarian, pancreatic, bladder and skin cancers. Carriers of biallelic MUTYH likely pathogenic/pathogenic variants exhibit a high lifetime risk of CRC, though cancer risk evidence becomes less clear when monoallelic carriers and extraintestinal tumors are considered. However, several studies recently reported an increased genetic susceptibility to cancer also for carriers of germline monoallelic MUTYH mutations. Moreover, experimental evidence highlighted the MUTYH involvement in many other biological functions. In future, MUTYH mutation carriers might benefit from new target therapies involving the use of PD-1 or KRAS inhibitors. Therefore, "MUTYH-associated tumor syndrome" might be the most appropriate term, due to the multiplicity of tumors observed in MAP patients and different biological contexts in which MUTYH acts as a "playmaker". In this Review, we will investigate the impact of germline mono- and biallelic MUTYH mutations on cancer risk, providing a proposal for clinical surveillance of mutation carriers.

Impact of Different Selection Approaches for Identifying Lynch Syndrome-Related Colorectal Cancer Patients: Unity Is Strength.

Lynch syndrome (LS) is an inherited genetic condition associated with increased predisposition to colorectal cancer (CRC) and other tumors and is caused by germline mutations in Mismatch Repair (MMR) or EPCAM genes. The identification of LS carriers is currently based on germline testing of subjects with MMR-deficient (dMMR) tumors or fulfilling clinical criteria, but the most efficient strategies to select patients who should be offered genetic testing are yet not well defined. In order to assess the most suitable selection mode to identify LS-related CRC patients, we retrospectively collected and analyzed all clinical and molecular information of 854 CRC patients, recruited from 2013 to 2021 at the University Hospital Policlinico "P. Giaccone" of Palermo (Italy), 100 of which were selected based on revised Bethesda guidelines, Amsterdam criteria II, or tissue MMR deficiency, and genetically tested for germline variants in LS-susceptibility genes. Our study showed that 32 out of 100 CRC patients harbored germline likely pathogenic/pathogenic variants in MMR genes. The analysis of tissue microsatellite instability (MSI) status according to the revised Bethesda guidelines has been to be the best selection approach. However, using different selection approaches as complementary strategies is useful to identify LS carriers, reducing underdiagnosis of this syndrome.

Can the tumor-agnostic evaluation of MSI/MMR status be the common denominator for the immunotherapy treatment of patients with several solid tumors?

Alterations in short-repetitive DNA sequences, known as microsatellite instability (MSI), can reflect deficiencies in Mismatch Repair (MMR) system which represents a major player in DNA integrity maintenance. The incidence of MSI-H/dMMR has been shown to be variable depending on the tumor type. Several studies confirmed that dMMR/MSI status, although less frequent than PD-L1 expression, may better predict response to immune-checkpoint inhibitors (ICIs) in patients with solid tumors. In October 2016, the FDA granted pembrolizumab as breakthrough therapy for the treatment of non-CRC, MSI-H/dMMR tumors, providing, for the first time, a tumor-agnostic indication. In the next future, the tissue-agnostic evaluation of MSI-H/dMMR could become the common denominator for the immunotherapy treatment of patients with different advanced solid tumors, in order to select patient subgroups which may benefit from this therapy. In this Review we provided an overview of the main clinical studies describing the association between MSI-H/dMMR tumors and immunotherapy response.

Not all KIT 557/558 codons mutations have the same prognostic influence on recurrence-free survival: breaking the exon 11 mutations in gastrointestinal stromal tumors (GISTs).

Background: Although the gastrointestinal stromal tumor (GIST) genotype is not currently included in risk-stratification systems, a growing body of evidence shows that the pathogenic variant (PV) type and codon location hold a strong prognostic influence on recurrence-free survival (RFS). This information has particular relevance in the adjuvant setting, where an accurate prognostication could help to better identify high-risk tumors and guide clinical decision-making. Materials and Methods: Between January 2005 and December 2020, 96 patients with completely resected GISTs harboring a KIT proto-oncogene receptor tyrosine kinase (KIT) exon 11 PV were included in the study. We analyzed the type and codon location of the PV according to clinicopathological characteristics and clinical outcome; the metastatic sites in relapsed patients were also investigated. Results: Tumors harboring a KIT exon 11 deletion or deletion/insertion involving the 557 and/or 558 codons, showed a more aggressive clinical behavior compared with tumors carrying deletion/deletion/insertion in other codons, or tumors with duplication/insertion/single-nucleotide variant (SNV) (7-year RFS: 50% versus 73.1% versus 88.2%, respectively; p < 0.001). Notably, among 18 relapsed patients with 557 and/or 558 deletion or deletion/insertion, 14 patients (77.8%) harbored deletions simultaneously involving 557 and 558 codons, while only 4 patients (22.2%) harbored deletions involving only 1 of the 557/558 codons. Thus, when 557 or 558 deletions occurred separately, the tumor showed a prognostic behavior similar to the GIST carrying deletions outside the 557/558 position. Remarkably, patients with GISTs stratified as intermediate risk, but carrying the 557/558 deletion, showed a similar outcome to the high-risk patients with tumors harboring deletions in codons other than 557/558, or duplication/insertion/SNV. Conclusion: Our data support the inclusion of the PV type and codon location in routine risk prediction models, and suggest that intermediate-risk patients whose GISTs harbor 557/558 deletions may also need to be treated with adjuvant imatinib like the high-risk patients.

POLE, POLD1, and NTHL1: the last but not the least hereditary cancer-predisposing genes.

POLE, POLD1, and NTHL1 are involved in DNA replication and have recently been recognized as hereditary cancer-predisposing genes, because their alterations are associated with colorectal cancer and other tumors. POLE/POLD1-associated syndrome shows an autosomal dominant inheritance, whereas NTHL1-associated syndrome follows an autosomal recessive pattern. Although the prevalence of germline monoallelic POLE/POLD1 and biallelic NTHL1 pathogenic variants is low, they determine different phenotypes with a broad tumor spectrum overlapping that of other hereditary conditions like Lynch Syndrome or Familial Adenomatous Polyposis. Endometrial and breast cancers, and probably ovarian and brain tumors are also associated with POLE/POLD1 alterations, while breast cancer and other unusual tumors are correlated with NTHL1 pathogenic variants. POLE-mutated colorectal and endometrial cancers are associated with better prognosis and may show favorable responses to immunotherapy. Since POLE/POLD1-mutated tumors show a high tumor mutational burden producing an increase in neoantigens, the identification of POLE/POLD1 alterations could help select patients suitable for immunotherapy treatment. In this review, we will investigate the role of POLE, POLD1, and NTHL1 genetic variants in cancer predisposition, discussing the potential future therapeutic applications and assessing the utility of performing a routine genetic testing for these genes, in order to implement prevention and surveillance strategies in mutation carriers.

Prevalence and Spectrum of Germline BRCA1 and BRCA2 Variants of Uncertain Significance in Breast/Ovarian Cancer: Mysterious Signals From the Genome.

About 10-20% of breast/ovarian (BC/OC) cancer patients undergoing germline BRCA1/2 genetic testing have been shown to harbor Variants of Uncertain Significance (VUSs). Since little is known about the prevalence of germline BRCA1/2 VUS in Southern Italy, our study aimed at describing the spectrum of these variants detected in BC/OC patients in order to improve the identification of potentially high-risk BRCA variants helpful in patient clinical management. Eight hundred and seventy-four BC or OC patients, enrolled from October 2016 to December 2020 at the "Sicilian Regional Center for the Prevention, Diagnosis and Treatment of Rare and Heredo-Familial Tumors" of University Hospital Policlinico "P. Giaccone" of Palermo, were genetically tested for germline BRCA1/2 variants through Next-Generation Sequencing analysis. The mutational screening showed that 639 (73.1%) out of 874 patients were BRCA-w.t., whereas 67 (7.7%) were carriers of germline BRCA1/2 VUSs, and 168 (19.2%) harbored germline BRCA1/2 pathogenic/likely pathogenic variants. Our analysis revealed the presence of 59 different VUSs detected in 67 patients, 46 of which were affected by BC and 21 by OC. Twenty-one (35.6%) out of 59 variants were located on BRCA1 gene, whereas 38 (64.4%) on BRCA2. We detected six alterations in BRCA1 and two in BRCA2 with unclear interpretation of clinical significance. Familial anamnesis of a patient harboring the BRCA1-c.3367G>T suggests for this variant a potential of pathogenicity, therefore it should be carefully investigated. Understanding clinical significance of germline BRCA1/2 VUS could improve, in future, the identification of potentially high-risk variants useful for clinical management of BC or OC patients and family members.

Challenges and advances for the treatment of renal cancer patients with brain metastases: From immunological background to upcoming clinical evidence on immune-checkpoint inhibitors.

The introduction of checkpoint inhibitors (ICIs) in renal cell carcinoma (RCC) treatment landscape, resulted in improvements in overall survival (OS) in metastatic patients. Brain metastases (BMs) are a specific metastatic site of interest representing a predictive factor of poor prognosis. Patients with BMs were usually excluded from prospective clinical trials in the past. Despite recent evidence suggest the efficacy and safety of ICIs, the BMs treatment remains a challenge; the immunotherapy responsiveness seems to be multifactorial and dependent on several factors, such as the genetic intratumor heterogeneity and the immunosuppressive role of the brain tumor microenvironment. This review, starting from the immunological background in RCC BMs, provide an overview of the upcoming evidence from clinical trials, address the issues related to the neuroradiological immunotherapy response evaluation and, with a look to the future, describes how the epigenetic modulation of immune evasion could represent a background for new therapeutic strategies.

Prognostic Role of Plasma PD-1, PD-L1, pan-BTN3As and BTN3A1 in Patients Affected by Metastatic Gastrointestinal Stromal Tumors: Can Immune Checkpoints Act as a Sentinel for Short-Term Survival?

Gastrointestinal stromal tumors (GISTs) represent 1% of all primary gastrointestinal tumors. Immune surveillance is often overcome by cancer cells due to the activation of immunoregulatory molecules such as programmed death protein (PD-1) and its ligand PD-L1, and butyrophilin sub-family 3A/CD277 receptors (BTN3A). Because several studies demonstrated that tumor PD-1 and PD-L1 expression may have a prominent prognostic function, this investigation aimed to discover if soluble forms of these molecules may be useful in predicting survival of metastatic GIST (mGIST) patients. Through specific ad hoc developed ELISA assays not yet available on the market, the circulating PD-1, PD-L1, BTN3A1, and pan-BTN3As levels were examined in 30 c-KIT exon 11-mutated mGIST patients, prior to imatinib therapy. Using specific thresholds derived by ROC analysis, we found that high baseline levels of sPD-1 (>8.1 ng/mL), sPD-L1 (>0.7 ng/mL), sBTN3A1 (>7.0 ng/mL), and pan-BTN3As (>5.0 ng/mL) were correlated with shorter progression-free survival (PFS) and poor prognosis. Contrariwise, subjects with lower plasma concentrations exhibited a median PFS about 20 months longer than to the earlier. Finally, an additional multivariate analysis revealed that circulating levels of sPD-L1 ≤ 0.7 ng/mL and pan-sBTN3As ≤ 5.0 ng/mL, and the absence of KIT exon 11 deletions or delins at codons 557 and/or 558 were associated with a longer PFS in mGIST patients. Our investigation, for the first time, revealed that evaluating the plasma concentration of some immune checkpoints may help prognosticate survival in mGIST patients, suggesting their potential use as prognostic biomarkers beyond the presence of KIT exon 11 Del or Delins at codons 557/558.

A "Lymphocyte MicroRNA Signature" as Predictive Biomarker of Immunotherapy Response and Plasma PD-1/PD-L1 Expression Levels in Patients with Metastatic Renal Cell Carcinoma: Pointing towards Epigenetic Reprogramming.

Introduction of checkpoint inhibitors resulted in durable responses and improvements in overall survival in advanced RCC patients, but the treatment efficacy is widely variable, and a considerable number of patients are resistant to PD-1/PD-L1 inhibition. This variability of clinical response makes necessary the discovery of predictive biomarkers for patient selection. Previous findings showed that the epigenetic modifications, including an extensive microRNA-mediated regulation of tumor suppressor genes, are key features of RCC. Based on this biological background, we hypothesized that a miRNA expression profile directly identified in the peripheral lymphocytes of the patients before and after the nivolumab administration could represent a step toward a real-time monitoring of the dynamic changes during cancer evolution and treatment. Interestingly, we found a specific subset of miRNAs, called "lymphocyte miRNA signature", specifically induced in long-responder patients (CR, PR, or SD to nivolumab >18 months). Focusing on the clinical translational potential of miRNAs in controlling the expression of immune checkpoints, we identified the association between the plasma levels of soluble PD-1/PD-L1 and expression of some lymphocyte miRNAs. These findings could help the development of novel dynamic predictive biomarkers urgently needed to predict the potential response to immunotherapy and to guide clinical decision-making in RCC patients.

Detection of Germline Mutations in a Cohort of 139 Patients with Bilateral Breast Cancer by Multi-Gene Panel Testing: Impact of Pathogenic Variants in Other Genes beyond BRCA1/2.

Patients with unilateral breast cancer (UBC) have an increased risk of developing bilateral breast cancer (BBC). The annual risk of contralateral BC is about 0.5%, but increases by up to 3% in BRCA1 or BRCA2 pathogenic variant (PV) carriers. Our study was aimed to evaluate whether all BBC patients should be offered multi-gene panel testing, regardless their cancer family history and age at diagnosis. We retrospectively collected all clinical information of 139 BBC patients genetically tested for germline PVs in different cancer susceptibility genes by NGS-based multi-gene panel testing. Our investigation revealed that 52 (37.4%) out of 139 BBC patients harbored germline PVs in high- and intermediate-penetrance breast cancer (BC) susceptibility genes including BRCA1, BRCA2, PTEN, PALB2, CHEK2, ATM, RAD51C. Nineteen out of 53 positively tested patients harbored a PV in a known BC susceptibility gene (no-BRCA). Interestingly, in the absence of an analysis performed via multi-gene panel, a significant proportion (14.4%) of PVs would have been lost. Therefore, offering a NGS-based multi-gene panel testing to all BBC patients may significantly increase the detection rates of germline PVs in other cancer susceptibility genes beyond BRCA1/2, avoiding underestimation of the number of individuals affected by a hereditary tumor syndrome.

BRCA1/2 pathogenic variants in triple-negative versus luminal-like breast cancers: genotype-phenotype correlation in a cohort of 531 patients.

BACKGROUND: Several available data suggest the association between specific molecular subtypes and BRCA1/2 mutational status. Previous investigations showed the association between BRCA1/2 pathogenic variants (PVs) in specific genomic regions and phenotypic variations of cancer relative risk, while the role of PV type and location in determining the breast cancer (BC) phenotypic features remains still unclear. The aim of this research was to describe the germline BRCA1/2 PVs in triple-negative breast cancer (TNBC) versus luminal-like BC and their potential leverage on BC phenotype. PATIENTS & METHODS: We retrospectively collected and analyzed all clinical information of 531 patients with BC genetically tested for germline BRCA1/2 PVs by Next-Generation Sequencing analysis at University Hospital Policlinico "P. Giaccone" of Palermo (Sicily) from January 2016 to February 2020. RESULTS: Our results corroborate the evidence that BRCA1-related tumors often have a profile which resembles the TNBC subtype, whereas BRCA2-associated tumors have a profile that resembles luminal-like BC, especially the Luminal B subtype. Interestingly, our findings suggest that the PVs identified in TNBC were not largely overlapping with those in luminal-like tumors. Differences in the frequency of two PVs potentially associated with different molecular tumor subtypes were observed. BRCA1-633delC was detected with relatively higher prevalence in patients with TNBC, whereas BRCA2-1466delT was found mainly in Luminal B tumors, but in no TNBC patient. CONCLUSION: Future studies examining the type and location of BRCA1/2 PVs within different molecular subtypes are required to verify our hypothesis and could provide an interesting insight into the complex topic of genotype-phenotype correlations. Additionally, a more in-depth understanding of the potential correlations between BRCA PVs and clinical and phenotypic features of hereditary BC syndrome patients could be the key to develop better strategies of prevention and surveillance in BRCA-positive carriers without disease.

Programmed Death Ligand 1 (PD-L1) as a Predictive Biomarker for Pembrolizumab Therapy in Patients with Advanced Non-Small-Cell Lung Cancer (NSCLC).

Recently, immunotherapy has been shown to be an effective and helpful therapeutic option for the treatment of advanced non-small-cell lung cancer (NSCLC). The activity of antitumor T cells may be restored through the checkpoint blockade using anti-programmed death 1 or anti-programmed death ligand 1 (PD-L1) antibodies, showing, in several cancer patients, an increased progression-free survival and overall survival compared with classical chemotherapy. As recently shown by several studies, the PD-L1 expression levels in tumors may offer a selection criterion for patients to predict their immunotherapy response. In particular, NSCLC patients with high tumor PD-L1 levels (proportional score ≥ 50% for first-line therapy and ≥ 1% for second-line treatment, respectively) showed better response rates to immunotherapy and longer survival in first-line therapy compared with conventional chemotherapy. PD-L1, whose expression is evaluated by using immunohistochemistry analysis, is currently the only biomarker approved for clinical use in the first- and second-line monotherapy setting and therefore plays a central role in treatment decision-making for patients with advanced NSCLC. In this review we will discuss the key role of PD-L1 as a predictive biomarker of response to pembrolizumab therapy in NSCLC patients by describing the appropriate techniques and methodologies for immunohistochemical evaluation of PD-L1 expression and providing an overview of the clinical studies supporting its predictive significance.