Ricardo R. Lastra

Tumor endothelium FasL establishes a selective immune barrier promoting tolerance in tumors

We describe a new mechanism regulating the tumor endothelial barrier and T cell infiltration into tumors. We detected selective expression of the death mediator Fas ligand (FasL, also called CD95L) in the vasculature of human and mouse solid tumors but not in normal vasculature. In these tumors, FasL expression was associated with scarce CD8+ infiltration and a predominance of FoxP3+ T regulatory (Treg) cells. Tumor-derived vascular endothelial growth factor A (VEGF-A), interleukin 10 (IL-10) and prostaglandin E2 (PGE2) cooperatively induced FasL expression in endothelial cells, which acquired the ability to kill effector CD8+ T cells but not Treg cells because of higher levels of c-FLIP expression in Treg cells. In mice, genetic or pharmacologic suppression of FasL produced a substantial increase in the influx of tumor-rejecting CD8+ over FoxP3+ T cells. Pharmacologic inhibition of VEGF and PGE2 produced a marked increase in the influx of tumor-rejecting CD8+ over FoxP3+ T cells that was dependent on attenuation of FasL expression and led to CD8-dependent tumor growth suppression. Thus, tumor paracrine mechanisms establish a tumor endothelial death barrier, which has a critical role in establishing immune tolerance and determining the fate of tumors.

Genomics of Ovarian Cancer Progression Reveals Diverse Metastatic Trajectories Including Intraepithelial Metastasis to the Fallopian Tube

Accumulating evidence has supported the fallopian tube rather than the ovary as the origin for high-grade serous ovarian cancer (HGSOC). To understand the relationship between putative precursor lesions and metastatic tumors, we performed whole-exome sequencing on specimens from eight HGSOC patient progression series consisting of serous tubal intraepithelial carcinomas (STIC), invasive fallopian tube lesions, invasive ovarian lesions, and omental metastases. Integration of copy number and somatic mutations revealed patient-specific patterns with similar mutational signatures and copy-number variation profiles across all anatomic sites, suggesting that genomic instability is an early event in HGSOC. Phylogenetic analyses supported STIC as precursor lesions in half of our patient cohort, but also identified STIC as metastases in 2 patients. Ex vivo assays revealed that HGSOC spheroids can implant in the fallopian tube epithelium and mimic STIC lesions. That STIC may represent metastases calls into question the assumption that STIC are always indicative of primary fallopian tube cancers. SIGNIFICANCE We find that the putative precursor lesions for HGSOC, STIC, possess most of the genomic aberrations present in advanced cancers. In addition, a proportion of STIC represent intraepithelial metastases to the fallopian tube rather than the origin of HGSOC. Cancer Discov; 6(12); 1342-51. ©2016 AACR.See related commentary by Swisher et al., p. 1309This article is highlighted in the In This Issue feature, p. 1293.

Integrative proteomic profiling of ovarian cancer cell lines reveals precursor cell associated proteins and functional status

A cell line representative of human high-grade serous ovarian cancer (HGSOC) should not only resemble its tumour of origin at the molecular level, but also demonstrate functional utility in pre-clinical investigations. Here, we report the integrated proteomic analysis of 26 ovarian cancer cell lines, HGSOC tumours, immortalized ovarian surface epithelial cells and fallopian tube epithelial cells via a single-run mass spectrometric workflow. The in-depth quantification of >10,000 proteins results in three distinct cell line categories: epithelial (group I), clear cell (group II) and mesenchymal (group III). We identify a 67-protein cell line signature, which separates our entire proteomic data set, as well as a confirmatory publicly available CPTAC/TCGA tumour proteome data set, into a predominantly epithelial and mesenchymal HGSOC tumour cluster. This proteomics-based epithelial/mesenchymal stratification of cell lines and human tumours indicates a possible origin of HGSOC either from the fallopian tube or from the ovarian surface epithelium.

Aggressive variants of follicular cell‐derived thyroid carcinomas: A cytopathologist's perspective

Follicular cell‐derived carcinomas of the thyroid gland comprise a heterogeneous group of malignant neoplasms of the thyroid gland with varied histologic appearance and molecular profiles. In most patients, these tumors represent relatively indolent neoplasms; however, certain subtypes/variants behave in an aggressive manner, and the recognition of this subset of tumors is essential because of their variable response to therapy and significant morbidity and mortality. Fine‐needle aspiration is considered an essential tool for the diagnosis of suspicious thyroid nodules. In this review, the authors discuss the clinical, histologic, and molecular findings and the prognostic implications of aggressive thyroid neoplasms with emphasis on the characteristic cytomorphologic features on fine‐needle aspiration smears. Cancer (Cancer Cytopathol) 2014;122:484–503.

Adequacy of fine-needle aspiration specimens for human papillomavirus infection molecular testing in head and neck squamous cell carcinoma.

Background: Head and neck squamous cell carcinoma is often associated with human papillomavirus (HPV) infection. Positive HPV status has been associated with increased response to treatment and improved prognosis in terms of recurrence-free and overall survival. In certain instances, diagnosis is performed through fine-needle aspiration of lymph nodes with metastatic carcinoma, often demonstrating extensive tumor necrosis. We evaluated the effect of tumor necrosis on deoxyribonucleic acid (DNA) adequacy for HPV molecular testing. Materials and Methods: Retrospective review of the pathology files at our institution identified cases of squamous cell carcinoma (SCC) diagnosed by fine-needle aspiration (FNA) on which HPV DNA molecular testing was performed. The cases were classified according to percent tumor necrosis into three categories (<10% necrosis, 10-70% necrosis and >70% necrosis) and the percentage of cases with adequate HPV DNA for molecular testing in each of the categories was compared. When available, p16 immunohistochemistry performed on the cases was compared with HPV status by molecular testing. Results: A total of 70 cases from 67 patients were included in the study. Adequate DNA for molecular HPV testing was obtained from samples of 47 cases (67%) while samples from 23 cases (33%) were inadequate for molecular testing. Of the adequate samples, 36 (77%) were positive and 11 (23%) were negative for high-risk HPV. Adequate DNA for testing was obtained in 22 out of 33 cases showing no necrosis (67%), 10 out of 16 cases showing partial necrosis (63%) and in 13 out of 17 cases showing extensive necrosis (76%). Conclusion: Our study found that HPV molecular testing is not influenced by percent tumor necrosis or method by which FNA was performed. We believe that a portion of the FNA specimen obtained from head and neck lesions diagnosed as SCC during the rapid on-site evaluation should be sent for HPV DNA testing, independent of the amount of tumor necrosis, thus guaranteeing availability of specimen for HPV testing.

MUM-1 expression differentiates tumors in the PEComa family from clear cell sarcoma and melanoma.

PEComas are mesenchymal neoplasms composed of perivascular epithelioid cells (PEC) and include a spectrum of tumors. PEComas and malignant melanoma share common morphological, immunohistochemical, and ultrastructural features, such as epithelioid cell morphology and melanocytic immunophenotype. Melanocytic markers commonly expressed in PEC tumors include HMB-45, Melan-A/MART-1, tyrosinase, microphthalmia transcription factor (MITF), and occasionally, S100. Given this morphological and immunophenotypical overlap, the differential diagnosis between a PEComa and malignant melanoma can represent a challenge. Additional diagnostic difficulty is the differentiation of melanoma and PEComa from clear cell sarcoma that is indistinguishable from melanoma based on the immunohistochemical profile. Recent studies have shown that MUM-1, a known lymphocyte marker shows positive immunostaining in nevi and melanomas, its expression in PEComas and clear cell sarcoma, however, has not been previously addressed. In this study, the authors analyzed MUM-1 expression using immunohistochemistry in PEComas (n = 8), the PEComa family members, angiomyolipomas (n = 13), and clear cell sarcomas (n = 11) and compared the staining pattern with malignant melanomas (n = 25), both primary (n = 14) and metastatic (n = 11). It was found that 92.3% of primary melanomas and 81.3% of metastatic melanomas were MUM-1 positive. In contrast, MUM-1 was only weakly positive in only 25% of PEComas and negative in all angiomyolipomas. MUM-1 expression was noted in 72.7% of clear cell sarcomas. The study demonstrated differential MUM-1 expression between PEComas and other true melanocytic tumors and suggested that the addition of MUM-1 to the usual panel of melanocyte markers could be a helpful adjunctive study to aid in the differential diagnosis between these entities.

Selective Glucocorticoid Receptor Modulators (SGRMs) Delay Castrate-Resistant Prostate Cancer Growth

Increased glucocorticoid receptor (GR) expression and activity following androgen blockade can contribute to castration-resistant prostate cancer (CRPC) progression. Therefore, we hypothesized that GR antagonism will have therapeutic benefit in CRPC. However, the FDA-approved nonselective, steroidal GR antagonist, mifepristone, lacks GR specificity, reducing its therapeutic potential. Here, we report that two novel nonsteroidal and highly selective GR modulators (SGRM), CORT118335 and CORT108297, have the ability to block GR activity in prostate cancer and slow CRPC progression. In contrast to mifepristone, these novel SGRMs did not affect androgen receptor (AR) signaling, but potently inhibited GR transcriptional activity. Importantly, SGRMs decreased GR-mediated tumor cell viability following AR blockade. In vivo, SGRMs significantly inhibited CRPC progression in high GR–expressing, but not in low GR–expressing xenograft models. Transcriptome analysis following AR blockade and GR activation revealed that these SGRMs block GR-mediated proliferative gene expression pathways. Furthermore, GR-regulated proliferation-associated genes AKAP12, FKBP5, SGK1, CEBPD, and ZBTB16 are inhibited by CORT108297 treatment in vivo. Together, these data suggest that GR-selective nonsteroidal SGRMs potently inhibit GR activity and prostate cancer growth despite AR pathway inhibition, demonstrating the therapeutic potential of SGRMs in GR-expressing CRPC. Mol Cancer Ther; 16(8); 1680–92. ©2017 AACR.

Invasive Stratified Mucin-producing Carcinoma and Stratified Mucin-producing Intraepithelial Lesion (SMILE): 15 Cases Presenting a Spectrum of Cervical Neoplasia With Description of a Distinctive Variant of Invasive Adenocarcinoma.

Stratified mucin-producing intraepithelial lesion (SMILE) is a cervical intraepithelial lesion, distinct from conventional squamous or glandular counterparts, believed to arise from embryonic cells at the transformation zone by transdifferentiation during high-risk HPV-associated carcinogenesis. It is characterized by stratified, immature epithelial cells displaying varying quantities of intracytoplasmic mucin throughout the majority of the lesional epithelium. We identified a distinct form of invasive cervical carcinoma with morphologic features identical to those in SMILE, which we have termed “invasive stratified mucin-producing carcinoma.” Fifteen cases from 15 patients (mean 36 y; range, 22 to 64 y) were retrieved from the pathology archives of multiple institutions with a diagnosis of either SMILE or invasive cervical carcinoma with a description or comment about the invasive tumor’s resemblance to SMILE. Seven cases had solely intraepithelial disease with a component of SMILE (mean 29 y; range, 22 to 40 y). The 8 other cases had invasive stratified mucin-producing carcinoma (mean 44; range, 34 to 64 y) in which SMILE was identified in 7. All cases of invasive stratified mucin-producing carcinoma demonstrated stratified, immature nuclei with intracytoplasmic mucin, which morphologically varied between cases from “mucin-rich” to “mucin-poor” in a similar manner to SMILE. All cases had mitotic figures and apoptotic debris, and an intralesional neutrophilic infiltrate was seen in the majority of cases. In cases of invasive carcinoma, the depth of invasion ranged from <1 to 19 mm. Follow-up information was available in 8 cases and ranged from 1 to 36 months (mean 11 mo). Three cases of invasive stratified mucin-producing carcinoma had biopsy or resection-proven metastatic carcinoma on follow-up. These 15 cases of cervical stratified mucin-producing lesions show a combination of intraepithelial and invasive growth patterns. Given that SMILE is well rooted as a distinct intraepithelial lesion, we propose “invasive stratified mucin-producing carcinoma” to describe its corresponding form of invasive carcinoma.

Granular cell tumors overexpress TFE3 without corollary gene rearrangement.

We read with interest the report by Chamberlain and investigators [1] on their immunophenotypic comparison of alveolar soft part sarcoma and granular cell tumor (GCT), particularly their finding of diffuse,marked positivity for TFE3 in 91% of GCTs. TFE3 is a ubiquitous transcription factor whose overexpression is useful to detect neoplasms of the TFE3 family with an underlying Xp11.2 translocation [2]. The observation of strong TFE3 immunolabeling in GCT by Chamberlain et al prompted us to examine GCT for TFE3 rearrangement to determine whether GCT may be included as a new member of the TFE3 family. Six cases of GCT were retrieved from our institutions archive for diagnosis verification, immunostaining for TFE3 (clone MRQ-37, prediluted, Ventana, Tucson, AZ; Ventana OptiView DAB Platform), and fluorescence in situ hybridization (FISH) using a validated TFE3 break-apart probe protocol [3]. Our case cohort comprised 5 women and 1 man ranging in age from 7 to 56 years with tumors involving the tongue, esophagus, breast, trachea, vulva, and skin. Intense and diffuse TFE3 positivity was seen in the nuclei of all 6 cases of GCT (Fig. A and B). FISH was negative for TFE3 rearrangement in every case. Our findings indicate that TFE3 is overexpressed in most GCTs, but there is no corollary gene rearrangement detectable by FISH. Although low-level TFE3 positivity can be seen in other neoplasms, reflecting the presence of native TFE3 protein and is not indicative of TFE3 rearrangement, the finding of intense and widespread nuclear TFE3 positivity is considered sensitive and specific for tumors with TFE3 fusion [2]. GCT is an exception in that overexpression of TFE3 protein does not appear to be linked to separation of the TFE3 gene. In the TFE3 tumor family, the mechanism for overexpression of TFE3 protein is not known. Some authors have proposed an error in native TFE3 degradation or promoter enhancement resulting in protein overproduction [2]. It is likely that GCTs harbor some kind of recurrent genetic alteration other than translocation of TFE3 to account for their increased levels of nuclear TFE3 protein.

Pattern-based classification of invasive endocervical adenocarcinoma, depth of invasion measurement and distinction from adenocarcinoma in situ: interobserver variation among gynecologic pathologists.

A pattern-based classification for invasive endocervical adenocarcinoma has been proposed as predictive of the risk of nodal metastases. We aimed to determine the reproducibility of such classification in the context of common diagnostic challenges: distinction between in situ and invasive adenocarcinoma and depth of invasion measurement. Nine gynecologic pathologists independently reviewed 96 cases of endocervical adenocarcinoma (two slides per case). They diagnosed each case as in situ or invasive carcinoma classifying the latter following the pattern-based classification as pattern A (non-destructive), B (focally destructive) or C (diffusely destructive). Depth of invasion, when applicable, was measured (mm). Overall, diagnostic reproducibility of pattern diagnosis was good (κ=0.65). Perfect agreement (9/9 reviewers) was seen in only 11 cases (11%), all destructively invasive (10 pattern C and 1 pattern B). In all, ≥5/9 reviewer concordance was achieved in 82/96 cases (85%). Distinction between in situ and invasive carcinoma, regardless of the pattern, showed only slight agreement (κ=0.37). Likewise, distinction restricted to in situ versus pattern A was poor (κ=0.23). Distinction between non-destructive (in situ+pattern A) and destructive (patterns B+C) carcinoma showed significantly higher agreement (κ=0.62). Estimation of depth of invasion showed excellent reproducibility (ICC=0.82). However, different measurements resulting in differing FIGO stages were common (from at least 1 reviewer in 79% cases). On the basis of interobserver agreement, the pattern-based classification is best at diagnosing destructive invasion, which carries a risk for nodal metastases. Agreement in diagnosing in situ versus invasive carcinoma, including pattern A, was poor. Given the nil risk of nodal spread in in situ and pattern A lesions, the term ‘endocervical adenocarcinoma with non-destructive growth’ can be considered when the distinction is difficult, after excluding destructive invasion. Depth of invasion measurement was highly reproducible among pathologists; thus, the pattern-based approach can complement, but should not replace, the depth of invasion metric.