Performance of MYC, BCL2, and BCL6 break-apart FISH in small biopsies with large B-cell lymphoma: a retrospective Cytopathology Hematopathology Interinstitutional Consortium study.

Introduction: Fluorescence in situ hybridization (FISH) is an essential ancillary study used to identify clinically aggressive subsets of large B-cell lymphomas that have MYC, BCL2, or BCL6 rearrangements. Small-volume biopsies such as fine needle aspiration biopsy (FNAB) and core needle biopsy (CNB) are increasingly used to diagnose lymphoma and obtain material for ancillary studies such as FISH. However, the performance of FISH in small biopsies has not been thoroughly evaluated or compared to surgical biopsies. Methods: We describe the results of MYC, BCL2, and BCL6 FISH in a series of 222 biopsy specimens, including FNAB with cell blocks, CNBs, and surgical excisional or incisional biopsies from 208 unique patients aggregated from 6 academic medical centers. A subset of patients had FNAB followed by a surgical biopsy (either CNB or excisional biopsy) obtained from the same or contiguous anatomic site as part of the same clinical workup; FISH results were compared for these paired specimens. Results: FISH had a low hybridization failure rate of around 1% across all specimen types. FISH identified concurrent MYC and BCL2 rearrangements in 20 of 197 (10%) specimens and concurrent MYC and BCL6 rearrangements in 3 of 182 (1.6%) specimens. The paired FNAB and surgical biopsy specimens did not show any discrepancies for MYC or BCL2 FISH; of the 17 patients with 34 paired cytology and surgical specimens, only 2 of the 49 FISH probes compared (4% of all comparisons) showed any discrepancy and both were at the BCL6 locus. One discrepancy was due to necrosis of the CNB specimen causing a false negative BCL6 FISH result when compared to the FNAB cell block that demonstrated a BCL6 rearrangement. Discussion: FISH showed a similar hybridization failure rate in all biopsy types. Ultimately, MYC, BCL2, or BCL6 FISH showed 96% concordance when compared across paired cytology and surgical specimens, suggesting FNAB with cell block is equivalent to other biopsy alternatives for evaluation of DLBCL or HGBCL FISH testing.

Scattering-Based Light-Sheet Microscopy Imaging of Human Papillomavirus-Associated Squamous Lesions of the Anal Canal: A Proof-of-Principle Study.

Demand for anal cancer screening is expected to rise following the recent publication of the Anal Cancer-HSIL Outcomes Research trial, which showed that treatment of high-grade squamous intraepithelial lesions significantly reduces the rate of progression to anal cancer. While screening for human papillomavirus-associated squamous lesions in the cervix is well established and effective, this is less true for other sites in the lower anogenital tract. Current anal cancer screening and prevention rely on high-resolution anoscopy with biopsies. This procedure has a steep learning curve for providers and may cause patient discomfort. Scattering-based light-sheet microscopy (sLSM) is a novel imaging modality with the potential to mitigate these challenges through real-time, microscopic visualization of disease-susceptible tissue. Here, we report a proof-of-principle study that establishes feasibility of dysplasia detection using an sLSM device. We imaged 110 anal biopsy specimens collected prospectively at our institution's dysplasia clinic (including 30 nondysplastic, 40 low-grade squamous intraepithelial lesion, and 40 high-grade squamous intraepithelial lesion specimens) and found that these optical images are highly interpretable and accurately recapitulate histopathologic features traditionally used for the diagnosis of human papillomavirus-associated squamous dysplasia. A reader study to assess diagnostic accuracy suggests that sLSM images are noninferior to hematoxylin and eosin images for the detection of anal dysplasia (sLSM accuracy = 0.87; hematoxylin and eosin accuracy = 0.80; P = .066). Given these results, we believe that sLSM technology holds great potential to enhance the efficacy of anal cancer screening by allowing accurate sampling of diagnostic tissue at the time of anoscopy. While the current imaging study was performed on ex vivo biopsy specimens, we are currently developing a handheld device for in vivo imaging that will provide immediate microscopic guidance to high-resolution anoscopy providers.

Intra- and post-pandemic impact of the COVID-19 outbreak on Stanford Health Care.

Stanford Health Care, which provides about 7% of overall healthcare to approximately 9 million people in the San Francisco Bay Area, has undergone significant changes due to the opening of a second hospital in late 2019 and, more importantly, the COVID-19 pandemic. We examine the impact of these events on anatomic pathology (AP) cases, aiming to enhance operational efficiency in response to evolving healthcare demands. We extracted historical census, admission, lab tests, operation, and AP data since 2015. An approximately 45% increase in the volume of laboratory tests (P < 0.0001) and a 17% increase in AP cases (P < 0.0001) occurred post-pandemic. These increases were associated with progressively increasing (P < 0.0001) hospital census. Census increase stemmed from higher admission through the emergency department (ED), and longer lengths of stay mostly for transfer patients, likely due to the greater capability of the new ED and changes in regional and local practice patterns post-pandemic. Higher census led to overcapacity, which has an inverted U relationship that peaked at 103% capacity for AP cases and 114% capacity for laboratory tests. Overcapacity led to a lower capability to perform clinical activities, particularly those related to surgical procedures. We conclude by suggesting parameters for optimal operations in the post-pandemic era.

NFE2L2 Mutations Enhance Radioresistance in Head and Neck Cancer by Modulating Intratumoral Myeloid Cells.

Radiotherapy (RT) is one of the primary treatments of head and neck squamous cell carcinoma (HNSCC), which has a high-risk of locoregional failure (LRF). Presently, there is no reliable predictive biomarker of radioresistance in HNSCC. Here, we found that mutations in NFE2L2, which encodes Nrf2, are associated with a significantly higher rate of LRF in patients with oral cavity cancer treated with surgery and adjuvant (chemo)radiotherapy but not in those treated with surgery alone. Somatic mutation of NFE2L2 led to Nrf2 activation and radioresistance in HNSCC cells. Tumors harboring mutant Nrf2E79Q were substantially more radioresistant than tumors with wild-type Nrf2 in immunocompetent mice, whereas the difference was diminished in immunocompromised mice. Nrf2E79Q enhanced radioresistance through increased recruitment of intratumoral polymorphonuclear myeloid-derived suppressor cells (PMN-MDSC) and reduction of M1-polarized macrophages. Treatment with the glutaminase inhibitor CB-839 overcame the radioresistance induced by Nrf2E79Q or Nrf2E79K. RT increased expression of PMN-MDSC-attracting chemokines, including CXCL1, CXLC3, and CSF3, in Nrf2E79Q-expressing tumors via the TLR4, which could be reversed by CB-839. This study provides insights into the impact of NFE2L2 mutations on radioresistance and suggests that CB-839 can increase radiosensitivity by switching intratumoral myeloid cells to an antitumor phenotype, supporting clinical testing of CB-839 with RT in HNSCC with NFE2L2 mutations. SIGNIFICANCE: NFE2L2 mutations are predictive biomarkers of radioresistance in head and neck cancer and confer sensitivity to glutaminase inhibitors to overcome radioresistance.

Identification of cell types in multiplexed in situ images by combining protein expression and spatial information using CELESTA.

Advances in multiplexed in situ imaging are revealing important insights in spatial biology. However, cell type identification remains a major challenge in imaging analysis, with most existing methods involving substantial manual assessment and subjective decisions for thousands of cells. We developed an unsupervised machine learning algorithm, CELESTA, which identifies the cell type of each cell, individually, using the cell's marker expression profile and, when needed, its spatial information. We demonstrate the performance of CELESTA on multiplexed immunofluorescence images of colorectal cancer and head and neck squamous cell carcinoma (HNSCC). Using the cell types identified by CELESTA, we identify tissue architecture associated with lymph node metastasis in HNSCC, and validate our findings in an independent cohort. By coupling our spatial analysis with single-cell RNA-sequencing data on proximal sections of the same specimens, we identify cell-cell crosstalk associated with lymph node metastasis, demonstrating the power of CELESTA to facilitate identification of clinically relevant interactions.

Lymph node colonization induces tumor-immune tolerance to promote distant metastasis.

For many solid malignancies, lymph node (LN) involvement represents a harbinger of distant metastatic disease and, therefore, an important prognostic factor. Beyond its utility as a biomarker, whether and how LN metastasis plays an active role in shaping distant metastasis remains an open question. Here, we develop a syngeneic melanoma mouse model of LN metastasis to investigate how tumors spread to LNs and whether LN colonization influences metastasis to distant tissues. We show that an epigenetically instilled tumor-intrinsic interferon response program confers enhanced LN metastatic potential by enabling the evasion of NK cells and promoting LN colonization. LN metastases resist T cell-mediated cytotoxicity, induce antigen-specific regulatory T cells, and generate tumor-specific immune tolerance that subsequently facilitates distant tumor colonization. These effects extend to human cancers and other murine cancer models, implicating a conserved systemic mechanism by which malignancies spread to distant organs.

Pilot study of loss of the p53/p63 target gene PERP at the surgical margin as a potential predictor of local relapse in head and neck squamous cell carcinoma.

BACKGROUND: PERP (p53 apoptosis effector related to PMP22) localizes to desmosomes and suppresses squamous cell carcinoma development. Loss of PERP leads to worse local control in head and neck squamous cell carcinoma (HNSCC), likely by destabilizing desmosomes. We evaluated PERP loss at HNSCC surgical margins as a predictor of local relapse. METHODS: Combining discovery (n = 17) and validation (n = 31) cohorts, we examined membranous PERP protein expression by immunohistochemistry in surgical mucosal margins with competing risk analysis of the relationship between local relapse and PERP expression. RESULTS: Of the 44 analyzable patients, the 2-year cumulative incidence of local relapse was 44.4% for the PERP-negative group and 16.4% for the PERP-positive group (P = .01). A trend toward worse progression-free survival (P = .09) and overall survival (P = .06) was observed with loss of PERP. CONCLUSIONS: PERP loss at surgical margins is associated with higher risk of local recurrence in HNSCC, warranting further evaluation in a larger prospective study.

Role of FNA with core biopsy or cell block in patients with nodular lymphocyte-predominant Hodgkin lymphoma.

BACKGROUND: Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) represents a diagnostic challenge on surgical excisional or incisional biopsy. Classification is further challenging on fine needle aspiration (FNA) material accompanied by needle core and/or cell block biopsy (FNA+core/CB). METHODS: The authors studied all FNA+core/CB and surgical excisional or incisional biopsies to evaluate for lymphoma in patients who had a prior history of NLPHL or subsequent diagnosis of NLPHL over a 5-year period from 2012 through 2016. RESULTS: Patients who ultimately were diagnosed with NLPHL represented <0.5% of those who underwent FNA+core/CB for an initial suspicion of lymphoma. FNA+core/CB resulted in a definitive diagnosis in 7 of 13 cases, and surgical excisional or incisional biopsy specimens resulted in a definitive diagnosis in 13 of 13 cases (chi-square statistic, 9.6; P = .002). At initial diagnosis, FNA+core/CB was negative in 2 cases and atypical or suspicious in 3 cases; all 5 of those patients required surgical excisional or incisional biopsy for a definitive lymphoma diagnosis. By contrast, patients who underwent FNA+core/CB for recurrent lymphoma required surgical excisional or incisional biopsy in only 1 of 8 cases (chi-square statistic, 9.5; P = .002). Flow cytometry was positive for a light-chain-restricted B-cell population in only 1 of 11 biopsies that were involved by lymphoma. CONCLUSIONS: Surgical excisional or incisional biopsy remains the gold standard for NLPHL diagnosis and for distinguishing progression to a T-cell/histiocyte-rich large B-cell lymphoma pattern. At a tertiary cancer center with routine collaborative diagnosis of lymphoma on FNA+core/CB by cytopathologists and hematopathologists, FNA+core/CB performs well to assess for recurrent or transformed NLPHL, rarely requiring subsequent surgical excisional or incisional biopsy. FNA+core/CB has limited sensitivity in the initial diagnosis setting.

Predicting Therapeutic Antibody Delivery into Human Head and Neck Cancers.

PURPOSE: The efficacy of antibody-based therapeutics depends on successful drug delivery into solid tumors; therefore, there is a clinical need to measure intratumoral antibody distribution. This study aims to develop and validate an imaging and computation platform to directly quantify and predict antibody delivery into human head and neck cancers in a clinical study. EXPERIMENTAL DESIGN: Twenty-four patients received systemic infusion of a near-infrared fluorescence-labeled therapeutic antibody followed by surgical tumor resection. A computational platform was developed to quantify the extent of heterogeneity of intratumoral antibody distribution. Both univariate and multivariate regression analyses were used to select the most predictive tumor biological factors for antibody delivery. Quantitative image features from the pretreatment MRI were extracted and correlated with fluorescence imaging of antibody delivery. RESULTS: This study not only confirmed heterogeneous intratumoral antibody distribution in-line with many preclinical reports, but also quantified the extent of interpatient, intertumor, and intratumor heterogeneity of antibody delivery. This study demonstrated the strong predictive value of tumor size for intratumoral antibody accumulation and its significant impact on antibody distribution in both primary tumor and lymph node metastasis. Furthermore, this study established the feasibility of using contrast-enhanced MRI to predict antibody delivery. CONCLUSIONS: This study provides a clinically translatable platform to measure antibody delivery into solid tumors and yields valuable insight into clinically relevant antibody tumor penetration, with implications in the selection of patients amenable to antibody therapy and the design of more effective dosing strategies.

A Thyroid Genetic Classifier Correctly Predicts Benign Nodules with Indeterminate Cytology: Two Independent, Multicenter, Prospective Validation Trials.

Background: Although most thyroid nodules with indeterminate cytology are benign, in most of the world, surgery remains as the most frequent diagnostic approach. We have previously reported a 10-gene thyroid genetic classifier, which accurately predicts benign thyroid nodules. The assay is a prototype diagnostic kit suitable for reference laboratory testing and could potentially avoid unnecessary diagnostic surgery in patients with indeterminate thyroid cytology. Methods: Classifier performance was tested in two independent, ethnically diverse, prospective multicenter trials (TGCT-1/Chile and TGCT-2/USA). A total of 4061 fine-needle aspirations were collected from 15 institutions, of which 897 (22%) were called indeterminate. The clinical site was blind to the classifier score and the clinical laboratory blind to the pathology report. A matched surgical pathology and valid classifier score was available for 270 samples. Results: Cohorts showed significant differences, including (i) clinical site patient source (academic, 43% and 97% for TGCT-1 and -2, respectively); (ii) ethnic diversity, with a greater proportion of the Hispanic population (40% vs. 3%) for TGCT-1 and a greater proportion of African American (11% vs. 0%) and Asian (10% vs. 1%) populations for TGCT-2; and (iii) tumor size (mean of 1.7 and 2.5 cm for TGCT-1 and -2, respectively). Overall, there were no differences in the histopathological profile between cohorts. Forty-one of 155 and 45 of 115 nodules were malignant (cancer prevalence of 26% and 39% for TGCT-1 and -2, respectively). The classifier predicted 37 of 41 and 41 of 45 malignant nodules, yielding a sensitivity of 90% [95% confidence interval; CI 77-97] and 91% [95% CI 79-98] for TGCT-1 and -2, respectively. One hundred one of 114 and 61 of 70 nodules were correctly predicted as benign, yielding a specificity of 89% [95% CI 82-94] and 87% [95% CI 77-94], respectively. The negative predictive values for TGCT-1 and TGCT-2 were 96% and 94%, respectively, whereas the positive predictive values were 74% and 82%, respectively. The overall accuracy for both cohorts was 89%. Conclusions: Clinical validation of the classifier demonstrates equivalent performance in two independent and ethnically diverse cohorts, accurately predicting benign thyroid nodules that can undergo surveillance as an alternative to diagnostic surgery.

Targeted deep sequencing of cell-free DNA in serous body cavity fluids with malignant, suspicious, and benign cytology.

BACKGROUND: Liquid biopsy using cell-free DNA (cfDNA) presents new opportunities for solid tumor genotyping. While studies have demonstrated the utility of cfDNA from plasma, cfDNA from other body fluids remains underexplored. METHODS: We evaluated the molecular features and clinicopathologic correlates of cfDNA from serous body cavity fluids by performing hybrid capture-based next-generation sequencing (NGS) on cfDNA isolated from residual effusion supernatants. Twenty-one serous effusions from pleural (n = 15), peritoneal (n = 5), and pericardial (n = 1) cavity were analyzed. RESULTS: The supernatants provided a median cfDNA concentration of 10.3 ng/µL. Notably, all effusions were sequenced successfully to a median depth >1000×, revealing a broad range of genetic alterations including single nucleotide variants, small insertions and deletions, amplifications, and fusions. Specifically, pathogenic alterations were identified in all malignant fluids (13/13), all fluids suspicious for malignancy (2/2), and 1 benign fluid (1/6) from a patient with metastatic cancer. To validate our findings, we examined matching results from 11 patients who underwent additional testing using formalin-fixed, paraffin-embedded (FFPE) specimens. In 8 patients, the paired results between FFPE and supernatant testing were concordant, whereas in the remaining 3 patients, supernatant analysis identified additional variants likely associated with resistance to targeted therapies. Additional comparison between FFPE and supernatant testing showed no difference in DNA concentration (P = .5), depth of coverage (P = .6), or allele frequency of pathogenic mutations (P = .7). CONCLUSION: cfDNA isolated from serous body cavity fluids represents a promising source of genomic input for targeted NGS.

Multiregion Quantification of Extracellular Signal-regulated Kinase Activity in Renal Cell Carcinoma.

To personalize treatment for renal cell carcinoma (RCC), it would be ideal to confirm the activity of druggable protein pathways within individual tumors. We have developed a high-resolution nanoimmunoassay (NIA) to measure protein activity with high precision in scant specimens (eg, fine needle aspirates [FNAs]). Here, we used NIA to determine whether protein activation varied in different regions of RCC tumors. Since most RCC therapies target angiogenesis by inhibiting the vascular endothelial growth factor (VEGF) receptor, we quantified phosphorylation of extracellular signal-regulated kinase (ERK), a downstream effector of the VEGF signaling pathway. In 90 ex vivo FNA biopsies sampled from multiple regions of 38 primary clear cell RCC tumors, ERK phosphorylation differed among patients. In contrast, within individual patients, we found limited intratumoral heterogeneity of ERK phosphorylation. Our results suggest that measuring ERK in a single FNA may be representative of ERK activity in different regions of the same tumor. As diagnostic and therapeutic protein biomarkers are being sought, NIA measurements of protein signaling may increase the clinical utility of renal mass biopsy and allow for the application of precision oncology for patients with localized and advanced RCC. PATIENT SUMMARY: In this report, we applied a new approach to measure the activity of extracellular signal-regulated kinase (ERK), a key cancer signaling protein, in different areas within kidney cancers. We found that ERK activity varied between patients, but that different regions within individual kidney tumors showed similar ERK activity. This suggests that a single biopsy of renal cell carcinoma may be sufficient to measure protein signaling activity to aid in precision oncology approaches.

Increased Galectin-1 Expression in Thymic Epithelial Tumors.

INTRODUCTION: Thymic epithelial tumors (TET) are rare malignancies with a paucity of data on biology and therapeutics. Galectin-1 is a member of the ß-galactoside binding protein family and has been shown to mediate tumor growth via modulation of immune cell function. This study examined galectin-1 expression in TET. PATIENTS AND METHODS: A tissue microarray of 68 patients with TET and 8 benign thymus controls were stained for galectin-1 expression and scored by a pathologist blinded to patient clinical and pathologic data. Galectin-1 expression +1 or greater staining intensity was considered positive. Clinical and pathologic data were abstracted from institutional databases. Expression of galectin-1 in thymic tumor was compared to benign thymus controls and correlated with pertinent clinical and pathologic data. RESULTS: Galectin-1 expression was higher in TET compared to benign thymus controls (65% vs. 0%). No significant association between galectin-1 expression and the development of recurrent disease, paraneoplastic syndromes, or overall survival was noted. CONCLUSION: Galectin-1 is overexpressed in the majority of TET. Detection of galectin-1 may differentiate benign from neoplastic thymic processes. Additional studies are needed to assess the role of galectin-1 in the development of TET.

Head and Neck Cancer in Haiti: A Case Series from Hopital de L'Universite d'Etat d'Haiti.

This manuscript characterizes the demographics, presenting symptoms and risk factors of patients diagnosed with head and neck cancer at Hopital de L'Universite d'Etat d'Haiti (HUEH), Haiti's single largest healthcare facility. We conducted a prospective study of patients who presented to HUEH between January and March of 2016 with a lesion of the head or neck suspicious for cancer. All patients who met eligibility criteria received a biopsy, which was interpreted by a Haitian pathologist and when the specimen was available was confirmed by a team of pathologists from Stanford University. A total of 34 participants were identified. The biopsy-confirmed diagnoses were squamous cell carcinoma (n=7), benign (n=7), large cell lymphoma (n=2), ameloblastoma (n=2), pleomorphic adenoma (n=1), and adenocarcinoma (n=1). Fourteen patients were unavailable for biopsy. Patients with head and neck cancer had a mean age of 63.4 years, were majority male (62.5%), waited on average 10.9 months to seek medical attention, and most commonly presented with T-stage 3 or higher disease (87.5%). By characterizing patterns of head and neck cancer at HUEH we hope to facilitate efforts to improve early detection, diagnosis, and management of this important public health condition.

Evaluation of diagnostic accuracy and a practical algorithmic approach for the diagnosis of renal masses by FNA.

BACKGROUND: The classification of renal neoplasms is essential for oncologic risk stratification and clinical management, and an accurate pretreatment pathologic diagnosis can provide useful guidance for active surveillance, minimally invasive ablative therapy, or surgical resection and can reduce the incidence of overtreatment. Previous studies evaluating the diagnostic accuracy of fine-needle aspiration (FNA) and core-needle biopsy (CNB) for renal masses are limited and show variable results. METHODS: Two hundred forty-seven renal FNA cases with or without concurrent CNB performed and/or reviewed at the Stanford University School of Medicine over the course of 20 years were identified. Cytohistopathologic correlation was performed for 77 cases with subsequent resection specimens. All available case materials were reviewed, and select cases were worked up further and reclassified as necessary. RESULTS: Cytohistopathologic correlation showed 96% diagnostic specificity and 83% sensitivity for renal FNA with or without concurrent CNB. Discordant cases were mostly attributed to sampling errors or suboptimal specimens (79%) and also included 2 non-renal cell carcinoma entities (1 case of angiomyolipoma and 1 case of a benign peripheral nerve sheath tumor) and 1 case involving misclassification of the renal cell carcinoma subtype. CONCLUSIONS: There is considerable value in FNA/CNB for the initial diagnosis of renal masses because of the high diagnostic specificity and sensitivity. Sensitivity is predominantly dependent on sufficient sampling, and additional potential diagnostic pitfalls include nonepithelial and rare entities. Judicious use of ancillary techniques is encouraged, especially when one is presented with a limited specimen, and this article presents a practical algorithmic approach to the diagnosis of renal masses using salient morphologic features and results from ancillary studies. Fine-needle aspiration is an accurate method for the diagnosis of renal masses. A practical diagnostic algorithm, based on salient morphologic and ancillary findings, is presented.

Clinical perineural invasion of cutaneous head and neck cancer: Impact of radiotherapy, imaging, and nerve growth factor receptors on symptom control and prognosis.

OBJECTIVES: Clinical perineural invasion (CPNI) of cutaneous head and neck cancer is associated with poor prognosis and presents a therapeutic dilemma. The purpose of this study was to determine the relationship between CPNI and nerve growth factor receptors (NGFR), and the impact of radiotherapy (RT), imaging, and NGFR on symptom control and disease-related outcomes. MATERIALS AND METHODS: We retrospectively reviewed patients with CPNI of cutaneous head and neck cancer who were treated with RT between 2010 and 2015 at our institution. Exact chi-square and Wilcoxon rank-sum tests compared patients with positive versus negative staining for TrkA and/or CD271. Gray's test determined differences in cumulative incidences of 1- and 2-year locoregional recurrence (LRR) and cancer-specific mortality (CSM). RESULTS: Twenty-three patients had a median overall follow-up of 31.4 months from initial clinical symptoms and 19.7 months from pathological confirmation of PNI. The most prevalent symptoms were numbness (70%) and pain (57%). Sixteen patients (70%) experienced symptom improvement or control, especially decreased pain (85%), within a median of 2.6 months from starting RT. The 1- and 2-year rates of overall LRR were 37% and 71%, while those of overall CSM were 11% and 25%, respectively. Patients who stained positively for TrkA and/or CD271 had significantly worse LRR compared to patients who stained negatively for both markers (p = 0.046). CONCLUSION: Positive TrkA and/or CD271 staining predicts worse outcomes. Patients may benefit from aggressive RT for local control and symptom improvement. Future research is needed to identify the potential for anti-nerve growth factor therapies in CPNI.

Flow immunophenotyping of benign lymph nodes sampled by FNA: Representative with diagnostic pitfalls.

BACKGROUND: Fine-needle aspiration with flow cytometry (FNA-FC) is routinely used in the evaluation of lymph nodes suspicious for lymphoma, yet data comparing immunophenotype distributions and outliers in benign lymph nodes sampled by fine-needle aspiration (FNA) versus excision are lacking. METHODS: Flow cytometry data from 289 benign lymph node FNA cases were assessed for the overall antigen distribution, with a focus on outliers relevant to the diagnosis of lymphoma. Distributions and outlier proportions were compared with those of a separate cohort of 298 excisional biopsies. RESULTS: Compared with excisional biopsies, FNA specimens overrepresented CD3+ events (72% vs 63%), underrepresented CD19+ events (22% vs 29%), and had 25% fewer large cell-gated events. Normalized antigen distributions in FNA were equivalent to those in excisional biopsy. Twenty-three percent of FNA-FC cases exhibited an outlier, including a skewed kappa:lambda light-chain ratio, increased CD5+ or CD10+ B-cell events, a skewed CD4:CD8 ratio, and increased CD7 loss on T cells, with no significant differences in frequency or type in comparison with excisional specimens. Outliers for the light-chain ratio and T-cell antigens were enriched among older patients and included patients with a variety of autoimmune/rheumatologic conditions. CONCLUSIONS: Benign lymph node FNA yields flow immunophenotypes remarkably similar to those from excisional biopsies. Outlier flow immunophenotypes are identified in benign lymph nodes sampled by FNA at a frequency similar to that with excisional biopsies. Older patients, who have a higher baseline risk of lymphoma, are more likely to exhibit lymphoma-mimicking outliers such as a light-chain predominance on B cells and skewed CD4:CD8 ratios or increased CD7 loss on T cells, and they warrant additional diagnostic caution.

Intertumoral Heterogeneity in SCLC Is Influenced by the Cell Type of Origin.

The extent to which early events shape tumor evolution is largely uncharacterized, even though a better understanding of these early events may help identify key vulnerabilities in advanced tumors. Here, using genetically defined mouse models of small cell lung cancer (SCLC), we uncovered distinct metastatic programs attributable to the cell type of origin. In one model, tumors gain metastatic ability through amplification of the transcription factor NFIB and a widespread increase in chromatin accessibility, whereas in the other model, tumors become metastatic in the absence of NFIB-driven chromatin alterations. Gene-expression and chromatin accessibility analyses identify distinct mechanisms as well as markers predictive of metastatic progression in both groups. Underlying the difference between the two programs was the cell type of origin of the tumors, with NFIB-independent metastases arising from mature neuroendocrine cells. Our findings underscore the importance of the identity of cell type of origin in influencing tumor evolution and metastatic mechanisms.Significance: We show that SCLC can arise from different cell types of origin, which profoundly influences the eventual genetic and epigenetic changes that enable metastatic progression. Understanding intertumoral heterogeneity in SCLC, and across cancer types, may illuminate mechanisms of tumor progression and uncover how the cell type of origin affects tumor evolution. Cancer Discov; 8(10); 1316-31. ©2018 AACR. See related commentary by Pozo et al., p. 1216 This article is highlighted in the In This Issue feature, p. 1195.

Determination of Tumor Margins with Surgical Specimen Mapping Using Near-Infrared Fluorescence.

For many solid tumors, surgical resection remains the gold standard and tumor-involved margins are associated with poor clinical outcomes. Near-infrared (NIR) fluorescence imaging using molecular agents has shown promise for in situ imaging during resection. However, for cancers with difficult imaging conditions, surgical value may lie in tumor mapping of surgical specimens. We thus evaluated a novel approach for real-time, intraoperative tumor margin assessment. Twenty-one adult patients with biopsy-confirmed squamous cell carcinoma arising from the head and neck (HNSCC) scheduled for standard-of-care surgery were enrolled. Cohort 1 (n = 3) received panitumumab-IRDye800CW at an intravenous microdose of 0.06 mg/kg, cohort 2A (n = 5) received 0.5 mg/kg, cohort 2B (n = 7) received 1 mg/kg, and cohort 3 (n = 6) received 50 mg. Patients were followed 30 days postinfusion and adverse events were recorded. Imaging was performed using several closed- and wide-field devices. Fluorescence was histologically correlated to determine sensitivity and specificity. In situ imaging demonstrated tumor-to-background ratio (TBR) of 2 to 3, compared with ex vivo specimen imaging TBR of 5 to 6. We obtained clear differentiation between tumor and normal tissue, with a 3-fold signal difference between positive and negative specimens (P < 0.05). We achieved high correlation of fluorescence intensity with tumor location with sensitivities and specificities >89%; fluorescence predicted distance of tumor tissue to the cut surface of the specimen. This novel method of detecting tumor-involved margins in surgical specimens using a cancer-specific agent provides highly sensitive and specific, real-time, intraoperative surgical navigation in resections with complex anatomy, which are otherwise less amenable to image guidance.Significance: This study demonstrates that fluorescence can be used as a sensitive and specific method of guiding surgeries for head and neck cancers and potentially other cancers with challenging imaging conditions, increasing the probability of complete resections and improving oncologic outcomes. Cancer Res; 78(17); 5144-54. ©2018 AACR.