Staining Of Tumor Cells Research Articles

Expression of Immune Response Markers in Arab Patients With Lung Cancer.

PURPOSEProgrammed death-ligand 1 (PD-L1) is a marker for checkpoint inhibitor use in the management of solid tumors, especially in non–small-cell lung cancer (NSCLC). Our study was aimed at determining the patterns of PD-L1 expression and cluster of differentiation 8 (CD8) immunostains in patients with NSCLC in the Arab population.METHODSArchival tumor tissue from patients with a confirmed diagnosis of NSCLC were obtained and stained for PD-L1 with antibody 22C3, using immunohistochemistry staining and giving the tumor proportion score (TPS) as a percentage from 0%-100% of stained tumor cells. Tumors were categorized into negative expressers (TPS < 1%), low positive (TPS, 1%-49%), and high positive (TPS, 50%-100%). Correlation of expression with clinical and pathologic features, including CD8-positive (CD8+) lymphocyte density, was also analyzed.RESULTSTwo hundred patients with NSCLC were included in the study from 6 centers in Saudi Arabia and Algeria. Median age was 65 years (28-93 years), and the majority were men (75%) with stage 4 NSCLC (64%). The TPS was high in 37 patients (18%), low in 60 patients (30%), and negative in 103 patients (52%). In a univariate analysis, the following were significant predictors of any PD-L1 expression (> 1%): male sex, being Saudi national patients, high expression of CD8+, and presence of tumor-infiltrating lymphocytes. In the multivariate analysis, only high expression of CD8+ cells (≥ 2+) was significant, with an odds ratio of 4.4 (95% CI, 1.5 to 12.9; P = .003)CONCLUSIONPD-L1 expression in our population is similar to the published literature and correlated with the density of CD8+ cells. Validation of the predictive value of this marker in our population and identifying easier and reliable methods to test for it are warranted.

EXPRESSION OF CD10 IN CARCINOMA PROSTATE AND ITS CORRELATION WITH VARIOUS CLINICOPATHOLOGICAL PARAMETERS.

Aim: Adenocarcinoma of the prostate is the second most common cause of cancer. Loss of CD10 is a common early event in human prostate cancer and is seen in lower Gleason Score malignancies while increased and altered expression is seen in high Gleason Score tumors, lymph node and bone metastasis. Materials and methods: The present study was a prospective observational study conducted on seventy-five patients suspected of having prostate cancer. Immunohistochemical profile was assessed for PSA, AMACR and CD10 immunostain. The intensity of CD10 expression and pattern of CD10 staining of tumor cells was evaluated. Results: The patients were in age group of 50-90 years with a mean age of 70.97 ± 9.51 years. As the grade group/gleason score increased the number of cases showing negative expression decreased and the pattern of expression changed from membranous to cytoplasmic to both types of expression. As the serum PSA levels increased the intensity of expression changed from focally positive to diffusely positive. The pattern of expression also changed from membranous to cytoplasmic to both ( membranous + cytoplasmic ) types of expression with increase in PSA levels. Conclusion: By immunohistochemical analysis we can identify CD10 positive tumors, which may warrant more aggressive initial therapy. A number of drugs against CD10 are available based on which potential targeted therapies could be formulated.

MYC expression has limited utility in the distinction of undifferentiated radiation-associated sarcomas from sporadic sarcomas and sarcomatoid carcinoma.

MYC is a proto-oncogene that is frequently dysregulated in various malignancies, through translocation or amplification. Radiation-associated angiosarcoma frequently shows MYC amplification, and immunohistochemical expression has been shown to be a reliable surrogate marker for amplification, but less is known about MYC expression in other sarcoma types, despite reports of MYC amplification in some undifferentiated/unclassified radiation-associated sarcomas (RASs). Distinguishing putative RAS from non-radiation-associated sarcoma or sarcomatoid carcinoma can be difficult. The aim of this study was to determine the prevalence and potential diagnostic utility of MYC in this context, by evaluating MYC expression in a cohort of RASs, non-radiation-associated sarcomas, and sarcomatoid carcinomas. Three hundred and eighty-five neoplasms were evaluated, including 81 RASs (18 angiosarcomas; 57 undifferentiated sarcomas; three leiomyosarcomas; and three malignant peripheral nerve sheath tumours), 267 non-radiation-associated sarcomas, and 37 sarcomatoid carcinomas. Immunohistochemistry was performed with a monoclonal anti-MYC antibody. Staining in tumour cells was scored on the basis of extent (focal, 1-4%; multifocal, 5-49%; and diffuse, ≥50%) and intensity (strong, moderate, and weak). One hundred percent of radiation-associated angiosarcomas expressed MYC diffusely. Expression was infrequent among other types of RAS (9.5%), and the frequency was similar to that in non-radiation-associated sarcomas (9.7%). MYC expression was more common in sarcomatoid carcinomas, occurring in 43%. The extent and intensity of staining were variable in all groups. MYC expression is infrequent among RASs other than angiosarcoma, and has a similar prevalence in sporadic sarcomas. Given the frequency of expression in sarcomatoid carcinomas, MYC expression outside the context of radiation-associated angiosarcoma is of limited diagnostic utility, and should be interpreted with caution after exclusion of sarcomatoid carcinoma where relevant.

A Bioresponsive Near-Infrared Fluorescent Probe for Facile and Persistent Live-Cell Tracking.

Molecular imaging significantly transforms the field of biomedical science and facilitates the visualization, characterization, and quantification of biologic processes. However, it is still challenging to monitor cell localization in vivo, which is essential to the study of tumor metastasis and in the development of cell-based therapies. While most conventional small-molecule fluorescent probes cannot afford durable cell labeling, transfection of cells with fluorescent proteins is limited by their fixed fluorescence, poor tissue penetration, and interference of autofluorescence background. Here, a bioresponsive near-infrared fluorescent probe is reported as facile and reliable tool for real-time cell tracking in vivo. The design of this probe relies on a new phenomenon observed upon fluorobenzene-conjugated fluorescent dyes, which can form complexes with cytosolic glutathione and actively translocates to lysosomes, exhibiting enhanced and stable cell labeling. Fluorobenzene-coupled hemicyanine, a near-infrared fluorophore manifests to efficiently staining tumor cells without affecting their invasive property and enables persistent monitoring of cell migration in metastatic tumor murine models at high resolution for one week. The method of fluorobenzene functionalization also provides a simple and universal "add-on" strategy to render ordinary fluorescent probes suitable for long-term live-cell tracking, for which currently there is a deficit of suitable molecular tools.

Prognostic impact of CD73 expression and its relationship to PD-L1 in patients with radically treated pancreatic cancer

Immune suppressing molecule CD73 is overexpressed in various cancers and associated with poor survival. Little is so far known about the predictive value of CD73 in pancreatic ductal adenocarcinoma (PDAC). The purpose of this study was to investigate the prognostic significance of CD73 in PDAC. The study material consisted of 110 radically treated patients for PDAC. Tissue microarray blocks were constructed and stained immunohistochemically using CD73 antibody. Staining intensity and numbers of stained tumour cells, inflammatory cells, stroma, and blood vessels were assessed. High-level CD73 expression in tumour cells was positively associated with PD-L1 expression, perineural invasion, and histopathological grade. CD73 positivity in tumour-infiltrating lymphocytes was significantly associated with lymph node metastasis. Lymphocytic CD73 positivity was also associated with staining positivity in both stroma and vascular structures. In addition, CD73 positivity in vascular structures and stroma were associated with each other. There were no significant associations between CD73 positive tumour cells and CD73 positivity in any other cell types. PD-L1 expression was associated with CD73 staining positivity in stroma (p = 0.007) and also with histopathological grade (p = 0.033) and T class (p = 0.016) of the primary tumour. CD73 positivity in tumour cells was significantly associated with poor disease-specific (p = 0.021) and overall survival (p = 0.016). In multivariate analysis, CD73 positivity in tumour cells was an independent negative prognostic factor together with histopathological grade, TNM stage, and low immune cell score. In conclusion, high CD73 expression in tumour cells is associated with poor survival in PDAC independently of the number of tumour-infiltrating lymphocytes or TNM stage.

The Utility of MYB Immunohistochemistry (IHC) in Fine Needle Aspiration (FNA) Diagnosis of Adenoid Cystic Carcinoma (AdCC).

Differentiating adenoid cystic carcinoma (AdCC) from other basaloid neoplasm in a fine needle aspiration (FNA) sample can be challenging. Activation of MYB in AdCC by the fusion transcript MYB-NFIB has been recently demonstrated in salivary gland and other organs. The aim of this study is to evaluate the utility of MYB immunohistochemistry (IHC) in distinguishing AdCCs and other basaloid neoplasm in cytology specimens. Eighteen FNA cases, from salivary gland and other sites, and their subsequent surgical resection specimens were included in the study. Eight cases were confirmed AdCC on resection. MYB IHC was performed on slides made from cytology cell block and surgical resection paraffin blocks. Percentage and intensity of nuclear staining in tumor cells was scored as 0 to 3. The staining results were concordant between cytology specimens and their corresponding surgical resection tumors. Strong diffuse nuclear staining (score 3, N = 5) was exclusively observed in AdCC, both in cytology and surgical specimens. Only one pleomorphic adenoma and one poorly differentiated basaloid carcinoma were positive for MYB staining (score 1 to 2). Any degree of nuclear MYB labeling was seen in 100% AdCC cases (N = 8/8) compared with of 20% (N = 2/10) of all other non-AdCC cases (P = < 0.001). The sensitivity and specificity of any degree MYB positivity for AdCC in cytology specimen is 100% and 78%. The sensitivity and specificity of strong diffuse MYB labeling (score 2 to 3) for AdCC is 83% and 100% in cytology specimen. Strong diffuse nuclear staining of MYB is valuable in supporting a cytologic diagnosis of AdCC. However, weak and focal labeling of MYB should be interpreted with caution as it can be seen in benign and other malignant basaloid lesions.

Large surgically resected leiomyosarcoma of the liver: a case report

BackgroundPrimary hepatic leiomyosarcoma (PHL) is an extremely rare type of tumor. We herein report a case of a large surgically resected leiomyosarcoma of the liver.Case presentationA 69-year-old man with a feeling of epigastric compression was referred for examination of an abdominal mass. He had no history of liver disease or alcohol abuse. Liver function tests indicated Child-Pugh class A. Tumor markers were negative. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed a relatively well-contrasted 12 × 11 × 8 cm tumor with well-defined boundary replacing the lateral segment of the liver alongside multiple intrahepatic metastases. Several nodules up to 12 mm were found in both lungs, suggestive of metastasis. SUVmax of the liver mass and lung tumor in positron emission tomography were 10.4 and 1.5, respectively. Hepatocellular carcinoma was primarily suspected. Lateral segmentectomy of the liver was performed to confirm diagnosis and prevent tumor rupture. Macroscopically, the lateral segment of the liver had been replaced by a lobular or multinodular tumor with a maximum diameter of 15 cm. In pathological findings, the tumor consisted of bundle-like proliferation of complicated banding spindle-like cells with clear cytoplasm, accompanied by storiform pattern and compressed blood vessels. Nuclear fission images were observed in 8/10 HPF. Partial necrosis was present, with associated venous invasion and intrahepatic metastasis. Immunohistochemical staining for tumor cells revealed desmin, α-smooth muscle actin (αSMA), and h-caldesmon were all positive, informing a final diagnosis of PHL. The postoperative course was uneventful, and he was discharged on the 12th postoperative day.ConclusionsPHL is a rare malignant disease with relatively poor prognosis. To confirm a diagnosis of PHL, immunohistochemical analysis as well as histopathological findings is important. The preferred treatment is surgical resection, sometimes in combination with adjuvant chemotherapy and radiotherapy. Further studies are needed to elucidate and better understand this uncommon clinical entity.

Abstract A15: Noncanonical NF-kappaB signaling is associated with poor ovarian cancer prognosis

Abstract Objective: Mediated by a family of transcription factors, the canonical and noncanonical nuclear factor-kappaB (NF-kB) signaling pathways have key roles in inflammation, innate immunity, and cancer development and progression. As prior ovarian cancer studies have evaluated only canonical NF-kB transcription factors in relation to survival, this study was undertaken to evaluate both canonical and noncanonical NF-kB pathway components in tumor samples from epithelial ovarian cancer cases from the Vanderbilt Tissue Repository for Ovarian Cancer (TROC). Methods: We abstracted clinical data from electronic medical records and assayed p65 (representing the canonical NF-kB pathway) and p52 (representing the noncanonical NF-kB pathway) by immunohistochemistry for 197 TROC samples. Nuclear and cytoplasmic staining in tumor cells was semiquantified by H-scores and dichotomized at median values. Associations with progression-free survival (PFS) and overall survival (OS) were quantified by hazard ratios (HR) and 95% confidence intervals (CI) using Cox proportional-hazards regression. Results: Median cytoplasmic and nuclear p65 and p52 H-scores were significantly higher among high-grade and serous cases; median p52 H-scores were also significantly higher among late-stage cases and patients treated with chemotherapy (all Wilcoxon rank sum p&amp;lt;0.05). In unadjusted regression models, higher nuclear p65 and higher nuclear p52 were associated with approximately 40% and 70% shorter PFS and OS, respectively, but these associations were attenuated by adjustment for age, stage, tumor type, race, chemotherapy, and residual disease. In multivariable adjusted models, higher cytoplasmic p52 was associated with more than 50% shorter PFS (HR 1.68, 95% CI 1.18-2.39) and OS (HR 1.53, 95% CI 1.06-2.21). Furthermore, when cytoplasmic and nuclear staining were combined, and mutually adjusted models included both p52 and p65, only p52 remained associated with worse PFS (HR 1.57, 95% CI 1.10-2.37) and OS (HR 1.51, 95% CI 1.05-2.15). Conclusions: This is the first study to demonstrate that p52, representing noncanonical NF-kB signaling, may be an independent prognostic factor for epithelial ovarian cancer. Approaches to inhibit noncanonical NF-kB signaling should be explored as novel therapies for ovarian cancer are needed. Citation Format: Demetra Hufnagel, Andrew J. Wilson, Jamie Saxon, Dineo Khabele, Timothy Blackwell, Marta A. Crispens, Fiona Yull, Alicia Beeghly-Fadiel. Noncanonical NF-kappaB signaling is associated with poor ovarian cancer prognosis [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research; 2019 Sep 13-16, 2019; Atlanta, GA. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(13_Suppl):Abstract nr A15.

The Clinical Importance of Androgen Receptor Status in Response to Neoadjuvant Chemotherapy in Turkish Patients with Local and Locally Advanced Breast Cancer

Purpose: To investigate whether androgen receptor (AR) status affects neoadjuvant chemotherapy (NACT) in stage II and III Turkish breast cancer patients. Methods: The histological response for breast and axilla was assessed according to the Miller-Payne grading system. In light microscopy, nuclear staining in tumor cells was evaluated, and nuclear staining above 1% was accepted as positive for AR expression. The patients were divided into 3 groups according to the intensity of AR staining: low, moderate, and high. Results: In total, 71 women with breast cancer were included in the study. In univariate analysis, age, menopause status, tumor diameter, stage, histological grade, Ki-67, estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 (HER-2) status were tested to determine which of these factors were associated with >90% responsiveness. AR negativity was found to be the only statistically significant factor. In multivariate analysis, AR positivity at each intensity was found to be the single important factor affecting decreasing pathologic response in patients receiving NACT for breast cancer. Conclusion: Our results show that AR positivity is associated with poor response to NACT in Turkish breast cancer patients and that AR positivity is independent of stage, hormone receptor status, HER-2 status, and disease stage.

Proteomic profiling of medulloblastoma reveals novel proteins differentially expressed within each molecular subgroup

ObjectivesThe objective of the study was to identify novel medulloblastoma (MB) biomarkers through proteomic profiling, correlate it with the molecular subgroups of MB and assess the clinical significance. MethodsArchived paraffin embedded tumor tissue blocks from 118 MB patients, operated at our institute were retrieved. Clinical information was documented from the hospital database. Tumours were stratified into molecular subgroups using the IHC markers- β Catenin, GAB-1, YAP-1 and p53. Six fresh MB tumour tissues and two control cerebellar tissues were subjected to proteomic profiling to study differential protein expression in molecular subgroups using high resolution mass spectrometry. Prominent signalling pathways activated in each subgroup were identified using the Panther pathway software. ResultsNon WNT/SHH group was the most common (61.1 %), followed by SHH and WNT. p53 immunopositivity did not correlate with prognosis in any subgroup. Proteomic profiling revealed several novel proteins differentially expressed between MB molecular subgroups. Signalling pathways exclusively enriched in each molecular subgroup were also identified. The top upregulated proteins were PMEL and FBN2 in the WNT subgroup, SYNGR2 in the SHH subgroup and GFAP, IMPG2 and MAGEA10 in the Non WNT/Non SHH group. We validated GFAP by immunohistochemistry on the archived samples (n = 118) and noted two types of staining pattern in MBs - reactive (stellate) astrocytes and tumour cell staining. GFAP immunopositivity in tumor cells of SHH subgroup correlated with a better prognosis. ConclusionsProteomic profile identified several novel proteins differentially regulated within the molecular subgroups that could serve as potential diagnostic /prognostic biomarkers. Notably, GFAP, which was derived from proteomics data, when validated by IHC, revealed a variable staining pattern in MB tumours. The prognostic significance of GFAP in SHH tumor patients further points at the heterogeneity of this subgroup. The study also throws light on the signaling pathways activated in MB and in turn its plausible role in the tumorigenesis.

Comprehensive assessment of PD-L1 immunohistochemistry on paired tissue and cytology specimens from non-small cell lung cancer

ObjectivesPD-L1 staining assessed by immunohistochemistry (IHC) is a predictive biomarker used to select advanced stage non-small cell lung carcinoma (NSCLC) patients who are likely to respond to PD-1/PD-L1 inhibitors. Cytology specimens represent a significant percentage of the diagnostic samples and additional data are required to show that they provide reliable PD-L1 results when compared to tissue specimens. We aimed to compare PD-L1 staining obtained from patient-matched tissue and cytology specimens. We also want to assess the feasibility of PD-L1 testing on cell blocks with two assays by evaluating the intra- and inter-observer agreement and the level of difficulty for determining the percentage of stained tumor cells (TPS). Materials and methodsForty-six patients with NSCLC were selected. Each patient provided a surgical specimen and a cytology sample (cell block) and/or a biopsy at diagnosis. PD-L1 staining using Agilent PD-L1 IHC 28-8 pharmDx and VENTANA PD-L1 (SP263) assays was evaluated by four pathologists using the TPS. Sixty slides were rescored to document intra-observer agreement. Pathologists were asked to score the level of difficulty for evaluating PD-L1 TPS for each slide. Fleiss’s and Cohen’s kappas (k) were used to assess the agreement between paired specimens as well as intra- and inter-observer agreement. ResultsThe concordance in PD-L1 TPS between cell blocks and surgical specimens (k varying from 0.56 to 0.82) or biopsies (k from 0.43 to 0.81) was moderate to substantial, depending on the cut-off. On cell blocks, inter-observer agreement was substantial (k from 0.74 to 0.82) and intra-observer agreement was almost perfect (k from 0.85 to 0.93). The perceived difficulty of PD-L1 evaluation of cell blocks was not different from surgical specimens but more difficult than biopsy samples. ConclusionPD-L1 TPS was concordant between cell blocks and tissue specimens, mainly at 10, 25 and 50 % cut-offs. PD-L1 evaluation on cell blocks was feasible and reproducible between different observers and assays.

Association of Programmed Death 1 Protein Ligand (PD-L1) Expression With Prognosis in Merkel Cell Carcinoma.

Background: Merkel cell carcinoma (MCC) is a rare neuroendocrine skin cancer. Prior to the advent of immunotherapy, treatment options were limited. In our study, we evaluate the impact of tumor cell PD-L1 expression and tumor immune microenvironment on survival in MCC patients who were not treated with immune checkpoint inhibitors.Methods: Clinical data and tissue samples were collected from 78 patients with confirmed MCC treated at Dana-Farber Cancer Institute. Specimens were analyzed for the distribution of PD-L1 by immunohistochemistry staining (IHC) and standardized analysis. Results were correlated with survival data.Results: In this study, membrane and cytoplasmic MCC tumor cell staining for PD-L1 was detected in 22.4% (15 of 67) of cases and PD-L1 staining of intratumoral microvessels and PD-L1 positive immune cells at the infiltrative margins of the tumor in 92.5% (62 of 67) of cases. In patients untreated with immune checkpoint inhibitors, median overall survival was not different for patients based on PD-L1 expression (PD-L1+ 64 months vs. PD-L1- not reached; HR = 1.26, 95% CI: 0.46–3.45; p = 0.60).Conclusion: PD-L1 expression is frequently detected in MCC tumor cells and tumor microenvironment. PD-L1 expression did not affect prognosis in this cohort that had not received PD-1/L1 blockade.

Prognostic impact of Dynamin related protein 1 (Drp1) in epithelial ovarian cancer

BackgroundThe mitochondrial fission protein, Dynamin related protein 1 (Drp1), and its upstream protein calcium/calmodulin–dependent protein kinase I (CaMKI) play a critical role in chemoresistance in ovarian cancer (OVCA). Thus, we examined the expression of Drp1, CaMKI and their phosphorylated forms and their prognostic impact in epithelial OVCA patients.MethodsExpression analysis was performed by immunohistochemistry (IHC) of paraffin-embedded tumor samples from 49 patients with epithelial OVCA. Staining intensity and the percentage of positively stained tumor cells were used to calculate an immunoreactive score (IRS) of 0–12. The expression scores calculated were correlated with clinicopathological parameters and patient survival.ResultsHigh immunoreactivity of phospho-Drp1Ser637 was significantly correlated with high-grade serous carcinoma (HGSC) (p = 0.034), residual postoperative tumor of > 1 cm (p = 0.006), and non-responders to adjuvant chemotherapy (p = 0.007), whereas high expression of CaMKI was significantly correlated with stage III/IV [International Federation of Gynecologists and Obstetricians (FIGO)] (p = 0.011) and platinum-resistant recurrence (p = 0.030). ROC curve analysis showed that Drp1, phospho-Drp1Ser637 and CaMKI could significantly detect tumor progression with 0.710, 0.779, and 0.686 of area under the curve (AUC), respectively. The Kaplan-Meier survival curve showed that patients with high Drp1, phospho-Drp1Ser637 and CaMKI levels had significantly poorer progression free survival (PFS) (p = 0.003, p < 0.001 and p = 0.017, respectively). Using multivariate analyses, phospho-Drp1Ser637 was significantly associated with PFS [p = 0.043, hazard ratio (HR) 3.151, 95% confidence interval (CI) 1.039–9.561].ConclusionsDrp1 and CaMKI are novel potential candidates for the detection and prognosis of epithelial OVCA and as such further studies should be performed to exploit their therapeutic significance.

Clinically aggressive malignancies associated with STK11 germline mutations (STK11GCa): A comprehensive genomic profiling (CGP) study.

3558 Background: Germline mutations in the STK11 ( LKB1) mTOR pathway gene are associated with Peutz-Jehger’s Syndrome and a variety of malignancies of variable clinical aggressiveness. Recent evidence also links STK11 inactivation with failure to benefit from anti-cancer immune checkpoint inhibitor (IO) therapy in NSCLC. Methods: Using hybrid capture based CGP on extracted tumor DNA and a published “somatic-germline-zygosity” SGZ data analysis algorithm on 212,470 samples of clinically advanced malignancies, we identified 103 (0.05%) STK11GCa inactivating base substitutions or indels. Tumor mutational burden (TMB) was determined on up to 1.1 Mbp of sequenced DNA and microsatellite instability (MSI) was determined on 114 loci. PD-L1 expression was determined by IHC (Dako 22C3). Results: 57 (55%) STK11GCa cases were NSCLC, 7 (7%) STK11GCa cases each were CRC, breast, pancreatic and unknown primary carcinomas, and 3 (3%) were gynecologic cancers. Amongst all samples included in this analysis, STK11 germline alterations were found in 0.15% NSCLC, 0.03% CRC, 0.03% breast, 0.08% pancreas, 0.06% unknown primary carcinoma and 0.03% of gynecologic cancers. Additional malignancies harboring STK11GCa included melanoma, gastroesophageal, HNSCC, bladder, HCC, lymphoma and mesothelioma. In STK11GCa, the median patient age at sequencing was 61 years (range 2 to &gt; 89 years); gender distribution was 52% female and 48% male. STK11GCa cases had a median of 6.5 genomic alterations (GA)/tumor and KEAP1, another IO resistance gene, was co-altered in 10%. Currently untargetable GA were detected in TP53 (50%), KRAS (38% with 9% in potentially targetable G12C), CDKN2A (32%), CDKN2B (22%), SMARCA4 (19%), MYC (11%), and APC (10%). Potentially targetable GA, which have also been linked in some studies to IO efficacy, included GA in BRAF (10%), EGFR (9%) and PBRM1 (4%). No targetable gene rearrangements or fusions were identified. No MSI High cases were identified. The median TMB was 5 mut/Mb with 23 % &gt;10 mut/Mb and 4% &gt;20 mut/Mb. 15% of 20 evaluated STK11GCA cases were PD-L1 high (&gt;50% tumor cell staining). Conclusions: STK11GCa include a wide variety of primary tumors with a paucity of co-occurring targetable GA. Although these tumors have significant PD-L1 staining and a subset harbor other markers of potential IO efficacy, the inactivated STK11 in these tumors may contribute to IO resistance and lack of responsiveness to immunotherapies.

Primary adult retroperitoneal sarcoma (RS): Comprehensive genomic profiling (CGP) study.

11541 Background: We performed CGP on 315 cases of RS to discover targetable genomic alterations (GA) and their potential impact on potential targeted and immunotherapy (IO) selection. Methods: FFPE tissues from 315 clinically advanced RS tissues underwent hybrid-capture based CGP (DNA and RNA). Tumor mutational burden (TMB) was determined on up to 1.2 Mbp of sequenced DNA, and tumor cell PD-L1 expression was determined by IHC (Dako 22C3) (low = 1-49%; High = &gt;50% tumor cell staining). Results: 155 liposarcomas (LPS), 74 leiomyosarcomas (LMS), 46 pleomorphic sarcomas (PLS), 7 solitary fibrous tumors (SFT), 6 malignant peripheral nerve sheath tumors (MPNST), 5 synovial sarcomas (SS) and 5 dendritic follicular cell sarcomas (DFCS) were studied; 17 cases were excluded. Median age was 59. There were 5.1 GA/tumor, none were MSI-high, median TMB was low at 2.4; PD-L1 IHC staining was low-positive in 21% and high-positive in 5%. MPNST patients were younger (median 28 years vs. 59 years). LPS was more frequent in men and LMS in women. LPS had more GA/tumor than LMS, with DFCS having the highest and SS the lowest. TP53 and RB1 GA were the highest in LMS and CDK4/6 and MDM2 GA the highest in LPS. Molecular targets in mTOR pathway were most frequently altered. Targetable gene fusions in ALK, ROS1 and NTRK1-3 were rare. Non-targetable fusions in HMGA2 (LPS and some PLS), STAT6 (SFT) and SS18 (SS) were also identified. Conclusions: RS in our cohort are predominantly composed of LPS, LMS and PLS and we identified a small proportion with “actionable” genomic targets on CGP, albeit in association with uncertain mTOR pathway inhibitor benefit and uncommon targetable kinase fusions. Our analysis suggests that a small subset of RS may respond to immunotherapy based on putative biomarker expression. [Table: see text]

Prognostic value of SOX2 and CD8+TIL in limited stage small cell lung cancer.

e21108 Background: SOX2 is a transcriptional factor that drives embryonic stem cell to neuroendocrine cells in lung development and is highly expressed in SCLC. The serum SOX2 antibody in SCLC has been known to mediate neurologic paraneoplastic syndrome. In this study, we evaluated the expression of SOX2 and CD8+ tumor infiltrating lymphocyte (TIL) in LS-SCLC from clinical tumor tissue and their impact on PFS and OS. Methods: Among the total 245 patients with SCLC treated between 2010 and 2018, 75 patients with LS-SCLC with available tumor tissue were enrolled. SOX2 and CD8+ TIL were evaluated by immunohistochemistry. High SOX2 expression was defined as above 100 of H score that was derived from multiplying intensity by the proportion of stained tumor cells. The number of CD8+TILs was counted under high magnification (x400) with four fields in intratumoral area. The cut value for high CD8+TIL was the above the median of total case. Results: 64 patients (85.4%) received etoposide/platinum and definite local therapy (radiation therapy or surgery) and 18 patients (24.0%) received surgical resection. High expression of CD8+ TIL was related to significantly longer PFS (13.9 vs. 8.0 months, P = 0.014) and tended to related to longer OS (32.1 vs. 17.4 months, P = 0.056) than low expression. High expression of SOX2 was tended to related with longer OS and PFS compared to low expression of SOX2 (median, 21.7 vs. 17.1 months, P = 0.118; 12.7 vs. 9.0 months, P = 0.110, respectively) without statistical significance. 29 patients with high CD8+TIL among 52 patients with high SOX2 had significantly longer PFS and OS compared to the other groups (median PFS 19.3 vs. 8.4 months, P = 0.002 and median OS 35.7 vs. 17.4 months, P = 0.004, respectively). Multivariate Cox regression analysis showed that combined high expression SOX2 and CD8+ TIL was an independent good prognostic factor for OS (HR = 0.449, P = 0.018) and PFS of SCLC (HR = 0.481, P = 0.021). Conclusions: In our study, high expression level of combined SOX2 and CD8+ TIL were related to longer OS and PFS, and it could be used as a prognostic biomarker for LS-SCLC. [Table: see text]

Expression of immune response markers in Arab patients with lung cancer.

e21543 Background: Programmed death-ligand 1 (PD-L1) is a marker for checkpoint inhibitors use in management of solid tumor especially non-small cell lung cancer (NSCLC). Our study aimed at determining the patterns of PD-L1 expression and CD8 immunostains in patients with NSCLC in Arab population. Methods: Archival tumor tissue form patients with confirmed diagnosis of NCSLC were obtained and stained for PD-L1 using antibody 22C3 by Dako using Immuno-histochemistry stain (IHC) and giving Tumor Proportion Score (TPS) a percentage number from 0 to 100% of stained tumor cells. Tumors were categorized into negative expressers (TPS&lt;1%), low positive (TPS 1-49%), and high positive (TPS 50% -100%). Correlation of expression with clinical and pathological features including CD8+ lymphocyte density was analyzed. Results: Two hundred NSCLC cases were included in the study from 6 centers in Saudi Arabia and Algeria. Median age was 65 years (28-93) and majority were males (75%) with stage 4 NSCLC (64%). The TPS was high in 37 patients (18%), low in 60 patients (30%), and negative in 103 patients (52%). In a univariate analysis, the following were significant predictors of any PD-L1 expression (&gt;1%): male gender, being Saudi national patients, high expression of CD8+ and the presence of tumor infiltrating lymphocytes. In the multivariate analysis, only high expression of CD8+ cells (&gt;2+) was significant with Odd Ratio (OR) of 4.4 (95% Confidence interval 1.5-12.9, p value of 0.003). Conclusions: PD-L1 expression in our population is similar to the published literature and correlated with the density of CD8+ cells. Validation of the predictive value of this marker in our population and identifying easier and reliable methods to test for it is warranted.

NTRK gene fusions in bilio-pancreatic cancers.

e16664 Background: Gene fusions involving one of the 3 neurotrophic tyrosine receptor kinases ( NTRK) have been identified in approximately 1% of solid tumors and inhibitors of TRK have been shown to have anti-tumor activity regardless of tumor type. NTRK gene fusions have been previously reported in bilio-pancreatic tumors. It is of interest therefore to determine incidence and molecular characteristics of NTRK gene fusions in these patients. Methods: Formalin-fixed paraffin-embedded archival blocks from surgical resections, biopsies or cytological samples of biliary tract tumors (BTC) including intra-hepatic (IH), extra-hepatic (EH), perihilar cholangiocarcinoma (PH) and gallbladder tumors (G), and pancreatic adenocarcinoma (PA) were retrieved from the tumor bank of CUB Hôpital Erasme between JAN 2010 and OCT 2019. A two-step diagnostic method incorporating immunohistochemistry (IHC) screening followed by NGS analysis was used. Pan–TRK IHC (monoclonal antibody clone EPR17341 [AbCam, Cambridge, MA]) was used for the screening method. Staining intensity (negative, weak, moderate or strong) pattern (diffuse, focal or rare positive cells), and localization (cytoplasmic or nuclear) were evaluated. The presence of at least weak staining tumor cells led to testing by a RNA-based NGS panel (Oncomine Focus Assay ThermoFisher Scientific). Results: For BTC, 162 archival tumors samples have been selected. 149 samples were suitable to perform IHC.17 samples were IHC positive including 9 IH, 3 PH, 2 EH and 3 G tumor samples. Intensity of staining was weak in 16 samples and moderate in one. Staining location was cytoplasmic (14/17), nuclear (2/17), and nuclear+cytoplasmic (1/17). Pattern of staining was rare positive cells (2/17), focal (4/17) and diffuse (11/17). NGS testing of the 17 IHC positive samples revealed a single NTRK3 gene fusion ( ETV6(4)- NTRK3(14)). In this PH tumor, IHC had a weak focal cytoplasmic and nuclear staining. Overall in the patients screened by IHC and confirmed by NGS, percentage of NTRK fusions was 0.67 %. For PA, 319 archival tumor samples have been selected and 297 were suitable for IHC. 19 samples were IHC positive. Intensity of staining was weak in 18 samples and moderate in one. Staining location was cytoplasmic (18/19) and nuclear (1/19). Pattern of staining was focal in 2 cases and diffuse in 17 cases. No fusion was detected by NGS. Conclusions: NTRK gene fusions are rare in bilio-pancreatic cancers but testing is of high interest due to the emergence of possible treatment with specific TRK inhibitors. These results support the use of NGS to confirm positive IHC results during diagnostic screening.

Galectin-9 expression as a poor prognostic factor in patients with renal cell carcinoma.

Recently, the effectiveness of anti-programmed death 1 (PD-1) antibody therapy in the treatment of renal cell carcinoma (RCC) has been established. Nevertheless, efficacy has been reported to be limited to only 10-30% of patients. To develop more effective immunotherapy for RCC, we analyzed the immunological characteristics in RCC tissues by immunohistochemistry (IHC). We prepared a tissue microarray that consisted of tumor tissue sections(1mm in diameter) from 83 RCC patients in Kanagawa Cancer Center between 2006 and 2015. IHC analysis was performed with antibodies specific to immune-related (CD8 and Foxp3) and immune checkpoint (programmed death ligand 1 (PD-L1) and 2 (PD-L2), B7-H4 and galectin-9) molecules. The numbers and proportions of positively stained tumor cells or immune cells were determined in each section. From multivariate analysis of all 83 patients, higher galectin-9 expression was detected as a factor associated with worse overall survival (OS) (P = 0.029) and that higher stage and higher B7-H4 expression were associated with worse progression-free survival (PFS) (P < 0.001 and P = 0.021, respectively). Similarly, in multivariate analysis of 69 patients with clear cell RCC, though not statistically significant, there was a trend for association between higher galectin-9 expression and worse OS (P = 0.067), while higher stage was associated with worse PFS (P < 0.001). This study suggests that higher galectin-9 expression is an independent adverse prognostic factor of OS in RCC patients. Therefore, to develop more effective personalized immunotherapy to treat RCC, it may be important to target not only PD-1/PD-L1, but also other immune checkpoint molecules such as galectin-9.

Correlation between the expression of folate receptor alpha (FRα) and clinicopathological features in patients with lung adenocarcinoma

ObjectivesFolate receptor alpha (FRα) is expressed on the cell surface, mediates its intracellular transport via receptor-mediated endocytosis, and is involved in cell division. Whether FRα could be a potential therapeutic target in FRα-expressing cancers remains unknown. Here, we retrospectively investigated the correlations between tumor FRα expression in lung adenocarcinoma (LADC) and clinicopathological features. Materials and methodsFRα expression was evaluated using a tissue microarray (TMA) constructed from surgical specimens of LADC and compared with clinicopathological features including the EGFR mutation status and the expressions of PD-L1, PD-L2, PD-1, CD4, CD8, CD204, and αSMA. If the proportion of positively stained tumor cells was greater than or equal to 5%, the tumor was considered to show FRα expression; if the H-score was more than or equal to 60, the tumor was considered to show high FRα expression. ResultsOverall, 466 TMA cores created from 233 LADC patients were evaluated: FRα-positive expression (FRα-pos)/negative (FRα-neg), 222/11; FRα high expression (FRα-HE)/low (FRα-LE), 190/43. AnEGFR mutation was present in 53.2 % of the patients. The median H-score of FRα expression, FRα-pos rate, and FRα-HE rate for EGFR mutation/wild type were 159/104 (p = 0.0002), 97.6/92.7 % (p = 0.0773), and 88.7/73.4 % (p = 0.0026), respectively. The H-scores for FRα had mild correlations with the proportion of tumor cells with positive staining for PD-L1 (r=-0.2557, p < 0.0001), the number of CD8-positive cells per square millimeter (r=-0.1767, p = 0.0069), and the area with positive staining for αSMA (r = 0.2049, p = 0.0017). No correlations were seen between FRα expression and other cancer-immunity markers. ConclusionTumor FRα expression was significantly higher in LADCs withEGFR mutation than in those with wild-type EGFR. This study suggested that FRα expression was related to cancer and microenvironment-immunity markers such as PD-L1 expression, CD8 cells, and αSMA.