Tribbles 2 pseudokinase confers enzalutamide resistance in prostate cancer by promoting lineage plasticity.

Enzalutamide, a second-generation antiandrogen, is commonly prescribed for the therapy of advanced prostate cancer, but enzalutamide-resistant, lethal, or incurable disease invariably develops. To understand the molecular mechanism(s) behind enzalutamide resistance, here, we comprehensively analyzed a range of prostate tumors and clinically relevant models by gene expression array, immunohistochemistry, and Western blot, which revealed that enzalutamide-resistant prostate cancer cells and tumors overexpress the pseudokinase, Tribbles 2 (TRIB2). Inhibition of TRIB2 decreases the viability of enzalutamide-resistant prostate cancer cells, suggesting a critical role of TRIB2 in these cells. Moreover, the overexpression of TRIB2 confers resistance in prostate cancer cells to clinically relevant doses of enzalutamide, and this resistance is lost upon inhibition of TRIB2. Interestingly, we found that TRIB2 downregulates the luminal markers androgen receptor and cytokeratin 8 in prostate cancer cells but upregulates the neuronal transcription factor BRN2 (Brain-2) and the stemness factor SOX2 (SRY-box 2) to induce neuroendocrine characteristics. Finally, we show that inhibition of either TRIB2 or its downstream targets, BRN2 or SOX2, resensitizes resistant prostate cancer cells to enzalutamide. Thus, TRIB2 emerges as a potential new regulator of transdifferentiation that confers enzalutamide resistance in prostate cancer cells via a mechanism involving increased cellular plasticity and lineage switching.

Convolutional Neural Network Quantification of Gleason Pattern 4 and Association With Biochemical Recurrence in Intermediate-Grade Prostate Tumors.

Differential classification of prostate cancer grade group (GG) 2 and 3 tumors remains challenging, likely because of the subjective quantification of the percentage of Gleason pattern 4 (%GP4). Artificial intelligence assessment of %GP4 may improve its accuracy and reproducibility and provide information for prognosis prediction. To investigate this potential, a convolutional neural network (CNN) model was trained to objectively identify and quantify Gleason pattern (GP) 3 and 4 areas, estimate %GP4, and assess whether CNN-predicted %GP4 is associated with biochemical recurrence (BCR) risk in intermediate-risk GG 2 and 3 tumors. The study was conducted in a radical prostatectomy cohort (1999-2012) of African American men from the Henry Ford Health System (Detroit, Michigan). A CNN model that could discriminate 4 tissue types (stroma, benign glands, GP3 glands, and GP4 glands) was developed using histopathologic images containing GG 1 (n = 45) and 4 (n = 20) tumor foci. The CNN model was applied to GG 2 (n = 153) and 3 (n = 62) tumors for %GP4 estimation, and Cox proportional hazard modeling was used to assess the association of %GP4 and BCR, accounting for other clinicopathologic features including GG. The CNN model achieved an overall accuracy of 86% in distinguishing the 4 tissue types. Furthermore, CNN-predicted %GP4 was significantly higher in GG 3 than in GG 2 tumors (P = 7.2 × 10-11). %GP4 was associated with an increased risk of BCR (adjusted hazard ratio, 1.09 per 10% increase in %GP4; P = .010) in GG 2 and 3 tumors. Within GG 2 tumors specifically, %GP4 was more strongly associated with BCR (adjusted hazard ratio, 1.12; P = .006). Our findings demonstrate the feasibility of CNN-predicted %GP4 estimation, which is associated with BCR risk. This objective approach could be added to the standard pathologic assessment for patients with GG 2 and 3 tumors and act as a surrogate for specialist genitourinary pathologist evaluation when such consultation is not available.

Multiethnic PDX models predict a possible immune signature associated with TNBC of African ancestry.

PURPOSE: Triple-negative breast cancer (TNBC) is an aggressive subtype most prevalent among women of Western Sub-Saharan African ancestry. It accounts for 15-25% of African American (AA) breast cancers (BC) and up to 80% of Ghanaian breast cancers, thus contributing to outcome disparities in BC for black women. The aggressive biology of TNBC has been shown to be regulated partially by breast cancer stem cells (BCSC) which mediate tumor recurrence and metastasis and are more abundant in African breast tumors. METHODS: We studied the biological differences between TNBC in women with African ancestry and those of Caucasian women by comparing the gene expression of the BCSC. From low-passage patient derived xenografts (PDX) from Ghanaian (GH), AA, and Caucasian American (CA) TNBCs, we sorted for and sequenced the stem cell populations and analyzed for differential gene enrichment. RESULTS: In our cohort of TNBC tumors, we observed that the ALDH expressing stem cells display distinct ethnic specific gene expression patterns, with the largest difference existing between the GH and AA ALDH+ cells. Furthermore, the tumors from the women of African ancestry [GH/AA] had ALDH stem cell (SC) enrichment for expression of immune related genes and processes. Among the significantly upregulated genes were CD274 (PD-L1), CXCR9, CXCR10 and IFI27, which could serve as potential drug targets. CONCLUSIONS: Further exploration of the role of immune regulated genes and biological processes in BCSC may offer insight into developing novel approaches to treating TNBC to help ameliorate survival disparities in women with African ancestry.

Clinical significance of quantitative categorization of HER2 fluorescent in situ hybridization results in invasive breast cancer patients treated with HER2-targeted agents.

HER2 (ERBB2) gene status serves as a strong predictive marker of response to HER2-targeted agents in invasive breast cancers, albeit with heterogeneous response. Our aim was to determine the distribution and prognosis of HER2 groups by fluorescent in situ hybridization (FISH) using the updated 2018 American Society of Clinical Oncology-College of American Pathologist (ASCO-CAP) guidelines. We identified 226 cases of equivocal or positive HER2 FISH invasive breast cancer (interpreted by ASCO-CAP guidelines at the time of reporting) who received HER2-targeted agents from 2006 to 2017. We subcategorized Group 1 further into three subgroups: low amplified (HER2/CEP17 ratio ≥ 2.0-2.99, mean HER2/cell 4.0-5.9), amplified (HER2/CEP17 ratio ≥ 2.0-2.99, mean HER2/cell ≥ 6), and excessive amplification (HER2/CEP17 ratio ≥ 3.0, mean HER2/cell ≥ 4.0). Outcomes studied were recurrence, metastasis, second breast primary, disease-specific survival (DSS), and overall survival (OS). Univariate analysis showed that the five categories of HER2 FISH were significantly associated with OS (p < 0.01), specifically higher HER2 amplification was associated with fewer deaths. HER2 FISH status also statistically significantly relates to DFS (p < 0.01) and metastasis (p = 0.01) but not with recurrence or second breast primary in our study. Tumor type and HER2 ISH Groups are independent predictors for both OS and DFS in our cohort. The proposed Group 1 subcategories were significantly associated with OS (p < 0.01) and DFS (p < 0.01), excessive HER2 amplification was associated with longer median survival. The Cox regression models showed better survival outcomes for the excessive amplification subgroup than the low amplified subgroup, with OS (hazard ratio = 0.63, 95% CI 0.42-0.93) and DFS (HR = 0.55, 95% CI 0.37-0.83). We demonstrated that in HER2 FISH Group 1 patients, high HER2 amplification was significantly associated with longer OS and DFS; these patients seem to benefit more from HER2-targeted regimens. We recommend reporting these Group 1 subcategories when assessing HER2 FISH.

The interplay of growth differentiation factor 15 (GDF15) expression and M2 macrophages during prostate carcinogenesis.

M2 (tumor-supportive) macrophages may upregulate growth differentiation factor 15 (GDF15), which is highly expressed in prostate tumors, but the combined utility of these markers as prognostic biomarkers are unclear. We retrospectively studied 90 prostate cancer cases that underwent radical prostatectomy as their primary treatment and were followed for biochemical recurrence (BCR). These cases also had a benign prostate biopsy at least 1 year or more before their prostate cancer surgery. Using computer algorithms to analyze digitalized immunohistochemically stained slides, GDF15 expression and the presence of M2 macrophages based on the relative density of CD204- and CD68-positive macrophages were measured in prostate: (i) benign biopsy, (ii) cancer and (iii) tumor-adjacent benign (TAB) tissue. Both M2 macrophages (P = 0.0004) and GDF15 (P < 0.0001) showed significant inter-region expression differences. Based on a Cox proportional hazards model, GDF15 expression was not associated with BCR but, in men where GDF15 expression differences between cancer and TAB were highest, the risk of BCR was significantly reduced (hazard ratio = 0.26; 95% confidence interval = 0.09-0.94). In addition, cases with high levels of M2 macrophages in prostate cancer had almost a 5-fold increased risk of BCR (P = 0.01). Expression of GDF15 in prostate TAB was associated with M2 macrophage levels in both prostate cancer and TAB and appeared to moderate M2-macrophage-associated BCR risk. In summary, the relationship of GDF15 expression and CD204-positive M2 macrophage levels is different in a prostate tumor environment compared with an earlier benign biopsy and, collectively, these markers may predict aggressive disease.

Clonal evaluation of early onset prostate cancer by expression profiling of ERG, SPINK1, ETV1, and ETV4 on whole-mount radical prostatectomy tissue.

BACKGROUND: Expression profiles of erythroblast transformation-specific (ETS)-related gene fusions and serine protease inhibitor Kazal-type 1 (SPINK1) in early onset prostate cancer have not been thoroughly explored. METHODS: We retrieved 151 radical prostatectomy specimens from young men with prostate cancer (<55 years) and characterized the expression of ETS-related gene (ERG), SPINK1, ETS Variant 1 (ETV1), and ETV4 by dual immunohistochemistry and dual RNA in situ hybridization. Age, race, family history, preoperative prostate-specific antigen, biochemical recurrence, and pathological variables using whole-mount radical prostatectomy tissue were collected. RESULTS: A total of 313 tumor nodules from 151 men including 68 (45%) Caucasians and 61 (40%) African Americans were included in the analysis. Positive family history of prostate cancer was seen in 65 (43%) patients. Preoperative prostate-specific antigen ranged from 0.3 to 52.7 ng/mL (mean = 7.04). The follow-up period ranged from 1 to 123.7 months (mean = 30.3). Biochemical recurrence was encountered in 8 of 151 (5%). ERG overexpression was observed in 85 of 151 (56%) cases, followed by SPINK1 in 61 of 151 (40%), ETV1 in 9 of 149 (6%), and ETV4 in 4 of 141 (3%). There were 25 of 151 (17%) cases showing both ERG and SPINK1 overexpression within different regions of either the same tumor focus or different foci. Higher frequency of ERG overexpression was seen in younger patients (≤45 years old; 76% vs 49%, P = .002), Caucasian men (71% vs 41% P = .0007), organ-confined tumors (64% vs 33%, P = .0008), and tumors of Gleason Grade groups 1 and 2 (62% vs 26%, P = .009). SPINK1 overexpression was more in African American men (68% vs 26%, P = .00008), in tumors with high tumor volume (>20%) and with anterior located tumors. ETV1 and ETV4 demonstrated rare overexpression in these tumors, particularly in the higher-grade tumors. CONCLUSION: This study expands the knowledge of the clonal evolution of multifocal cancer in young patients and support differences in relation to racial background and genetics of prostate cancer.

Clonal evaluation of prostate cancer molecular heterogeneity in biopsy samples by dual immunohistochemistry and dual RNA in situ hybridization.

Prostate cancer is frequently multifocal. Although there may be morphological variation, the genetic underpinnings of each tumor are not clearly understood. To assess the inter and intra tumor molecular heterogeneity in prostate biopsy samples, we developed a combined immunohistochemistry and RNA in situ hybridization method for the simultaneous evaluation of ERG, SPINK1, ETV1, and ETV4. Screening of 601 biopsy cores from 120 consecutive patients revealed multiple alterations in a mutually exclusive manner in 37% of patients, suggesting multifocal tumors with considerable genetic differences. Furthermore, the incidence of molecular heterogeneity was higher in African Americans patients compared with Caucasian American patients. About 47% of the biopsy cores with discontinuous tumor foci showed clonal differences with distinct molecular aberrations. ERG positivity occurred in low-grade cancer, whereas ETV4 expression was observed mostly in high-grade cancer. Further studies revealed correlation between the incidence of molecular markers and clinical and pathologic findings, suggesting potential implications for diagnostic pathology practice, such as defining dominant tumor nodules and discriminating juxtaposed but molecularly different tumors of different grade patterns.

Gene fusion characterisation of rare aggressive prostate cancer variants-adenosquamous carcinoma, pleomorphic giant-cell carcinoma, and sarcomatoid carcinoma: an analysis of 19 cases.

AIMS: To evaluate the molecular underpinnings of the rare aggressive prostate cancer variants adenosquamous carcinoma, pleomorphic giant-cell carcinoma, and sarcomatoid carcinoma. METHODS AND RESULTS: We retrieved 19 tumours with one or more variant(s), and performed ERG immunohistochemistry, a next-generation sequencing assay targeting recurrent gene fusions, and fluorescence in-situ hybridisation (FISH) for ERG and BRAF. Divergent differentiation included: sarcomatoid carcinoma (n = 10), adenosquamous carcinoma (n = 7), and pleomorphic giant-cell carcinoma (n = 7). Five patients had more than one variant. Four had variants only in metastases. ERG rearrangement was detected in nine (47%, seven via sequencing, showing TMPRSS2-ERG fusions and one GRHL2-ERG fusion, and two via FISH, showing rearrangement via deletion). ERG was immunohistochemically positive in the adenocarcinoma in eight of nine (89%) patients, but was immunohistochemically positive in the variant in only five of nine patients (56%, typically decreased). One patient had a false-positive ERG immunohistochemical result in the sarcomatoid component despite a negative FISH result. Two (11%) harboured BRAF fusions (FAM131A-BRAF and SND1-BRAF). CONCLUSIONS: ERG fusions are present in these rare prostate cancer variants with a frequency close to that in conventional prostate cancer (9/19, 47%). ERG immunohistochemistry usually detects rearrangement in the adenocarcinoma, but is less sensitive for the variant histology, with weak to negative staining. Adenosquamous and sarcomatoid variants can, particularly, occur together. Molecular assessment may be an additional tool in selected cases to confirm the prostatic origin of unusual tumours. The presence of two BRAF rearrangements suggests that this gene fusion may be enriched in this setting, as RAF kinase fusions have been previously reported in 1-2% of prostate cancers.

A pediatric case of pigmented epithelioid melanocytoma with chromosomal copy number alterations in 15q and 17q and a novel NTRK3-SCAPER gene fusion.

Pigmented epithelioid melanocytoma (PEM) represents a group of rare, heavily pigmented melanocytic tumors encompassing lesions previously designated as "animal-type melanomas" and "epithelioid blue nevi." Despite the association of multiple such tumors in the setting of Carney complex, most cases of PEM occur spontaneously as solitary neoplasms in otherwise healthy patients. PEM may arise in both children and adults, and has a known propensity to spread to the regional lymph nodes. Despite this latter finding, recurrence at the biopsy site or spread beyond the lymph node basin is exceptionally uncommon. Although the molecular basis for PEM continues to be characterized, findings to date suggest that this category of melanocytic neoplasia has genetic alterations distinct from those seen in common nevi, dysplastic nevi, Spitz nevi, and melanoma. Herein, we present an in-depth clinical, histopathologic, and molecular analysis of a case of PEM occurring on the scalp of a young African American girl found to have a novel NTRK3-SCAPER gene fusion.

Potential effect of anti-inflammatory drug use on PSA kinetics and subsequent prostate cancer diagnosis: Risk stratification in black and white men with benign prostate biopsy.

BACKGROUND: Rising prostate-specific antigen (PSA) levels are associated with both increased risk of prostate cancer and prostatic inflammation. The confounding effects of inflammation on the utility of PSA kinetics to predict prostate cancer may be partially mitigated by anti-inflammatory drug use. We investigated the influence of anti-inflammatory drug use on the association of PSA kinetics with prostate cancer risk. METHODS: We studied 488 prostate cancer case-control pairs (290 white, 198 African American (AA)) nested in a retrospective cohort of men with a benign prostate biopsy. A series of multivariable models estimated prostate cancer risk associated with PSA velocity (PSAV) at different levels of anti-inflammatory drug use while adjusting for the presence of both clinical and histologic prostatitis. RESULTS: In men with one, two, or three or more courses of anti-inflammatory drug use, for each ng/mL/year increase in PSAV, prostate cancer risk increased 1.21-fold, 1.83-fold, and 1.97-fold, respectively ( P < 0.0001). In controls with histologic prostatitis, anti-inflammatory drug use was associated with a significantly lower PSAV ( P < 0.0001). This association was not observed in men with histologic prostatitis who were subsequently diagnosed with prostate cancer. A positive interaction between anti-inflammatory drug use and PSAV-associated prostate cancer risk was only observed in AA men, as well as a strong positive association between any anti-inflammatory drug use and clinical prostatitis ( P = 0.004). CONCLUSIONS: In men with benign prostate biopsy, accounting for the presence of histologic prostatitis and anti-inflammatory drug use, particularly in AA men, may help distinguish between men with rising PSA because of prostatitis vs undiagnosed cancer.

Hereditary Susceptibility for Triple Negative Breast Cancer Associated With Western Sub-Saharan African Ancestry: Results From an International Surgical Breast Cancer Collaborative.

OBJECTIVE: To investigate subtype-specific risk of germline alleles associated with triple negative breast cancer (TNBC) in African ancestry populations. BACKGROUND: Breast cancer (BC) mortality is higher in African American (AA) compared to White American (WA) women; this disparity is partly explained by 2-fold higher TNBC incidence. METHODS: We used a surgically maintained biospecimen cohort of 2884 BC cases. Subsets of the total (760 AA; 962 WA; 910 West African/Ghanaian; 252 East African/Ethiopian) were analyzed for genotypes of candidate alleles. A subset of 417 healthy controls were also genotyped, to measure associations with overall BC risk and TNBC. RESULTS: TNBC frequency was highest in Ghanaian and AA cases (49% and 44% respectively; P < 0.0001) and lowest in Ethiopian and WA cases (17% and 24% respectively; P < 0.0001). TNBC cases had higher West African ancestry than non-TNBC (P < 0.0001). Frequency of the Duffy-null allele (rs2814778; an African ancestral variant adopted under selective pressure as protection against malaria) was associated with TNBC-specific risk (P < 0.0001), quantified West African Ancestry (P < 0.0001) and was more common in AA, Ghanaians, and TNBC cases. Additionally, rs4849887 was significantly associated with overall BC risk, and both rs2363956 and rs13000023 were associated with TNBC-specific risk, although none as strongly as the Duffy-null variant. CONCLUSIONS: West African ancestry is strongly correlated with TNBC status, as well as germline variants related to BC risk. The Duffy-null allele was associated with TNBC risk in our cohort.

Triple-Negative Breast Cancer, Stem Cells, and African Ancestry.

Triple-negative breast cancers (TNBCs) are more common among African-ancestry populations, such as African Americans and western, sub-Saharan Africans, compared with European-ancestry populations. This phenotype prevalence contributes to disparities in breast cancer outcomes between African Americans and White Americans. Breast cancer stem cells represent the tumor subpopulation involved in metastatic virulence, and ongoing research seeks to characterize the extent to which TNBC versus non-TNBC stem cells may differ. This review summarizes the existing literature regarding TNBCs and stem cells as they pertain to the burden of breast cancer among African-ancestry populations. Additional research related to variations in somatic tumor genomics between the African-American and White-American populations is also summarized. This review furthermore explores the history of insights regarding breast cancer disparities related to racial/ethnic identity, socioeconomic status, and tumor biology.

Distribution and Short-term Prognostic Value of the 21-gene recurrence score in African American compared to White American breast cancer patients.

We evaluated 328 patients (34.8% African American [AA]; 65.2% White American [WA]) with hormone receptor-positive, HER2/neu-negative breast cancer. Mean age (60 years); mean tumor size (1.6 and 1.7 cm for AA and WA, respectively) were similar, and mean BMI was higher for AA (33 vs 29.8; P = 0.001). Recurrence score (RS) distribution was similar- 8.3% AA and 5.9% WA with high RS (≥31). No significant differences were observed in delivery of chemotherapy stratified by score. With median follow-up 27.2 months for AA and 33.4 months for WA, distant recurrence occurred in 1.0% and 1.6%, respectively (P = 1). Our results suggest comparable RS utility in AA and WA patients.

Breast cancer risk and germline genomic profiling of women with neurofibromatosis type 1 who developed breast cancer.

NF1 mutations predispose to neurofibromatosis type 1 (NF1) and women with NF1 have a moderately elevated risk for breast cancer, especially under age 50. Germline genomic analysis may better define the risk so screening and prevention can be applied to the individuals who benefit the most. Survey conducted in several neurofibromatosis clinics in the United States has demonstrated a 17.2% lifetime risk of breast cancer in women affected with NF1. Cumulated risk to age 50 is estimated to be 9.27%. For genomic profiling, fourteen women with NF1 and a history of breast cancer were recruited and underwent whole exome sequencing (WES), targeted genomic DNA based and RNA-based analysis of the NF1 gene. Deleterious NF1 pathogenic variants were identified in each woman. Frameshift mutations because of deletion/duplication/complex rearrangement were found in 50% (7/14) of the cases, nonsense mutations in 21% (3/14), in-frame splice mutations in 21% (3/14), and one case of missense mutation (7%, 1/14). No deleterious mutation was found in the following high/moderate-penetrance breast cancer genes: ATM, BRCA1, BRCA2, BARD1, BRIP1, CDH1, CHEK2, FANCC, MRE11A, NBN, PALB2, PTEN, RAD50, RAD51C, TP53, and STK11. Twenty-five rare or common variants in cancer related genes were discovered and may have contributed to the breast cancers in these individuals. Breast cancer predisposition modifiers in women with NF1 may involve a great variety of molecular and cellular functions.

Utilization of the 21-Gene Recurrence Score in a Diverse Breast Cancer Patient Population: Development of a Clinicopathologic Model to Predict High-Risk Scores and Response to Neoadjuvant Chemotherapy.

INTRODUCTION: The 21-gene expression profile [Oncotype DX Recurrence Score (RS)] stratifies benefit from adjuvant chemotherapy in hormone receptor (HR)-positive, HER2/neu-negative, node-negative breast cancer. It is not routinely applied to predict neoadjuvant chemotherapy (NACT) response; data in diverse patient populations also are limited. We developed a statistical model based on standard clinicopathologic features to identify high-risk cases (RS > 30) and then evaluated ability of predicted high RS to predict for NACT downstaging. METHODS: Primary surgery patients with Oncotype DX RS testing 2012-2016 were identified from a prospectively-maintained database. A RS predictive model was created and applied to a dataset of comparable NACT patients. Response was defined as tumor size decrease ≥ 1 cm. RESULTS: Of 394 primary surgery patients-60.4% white American; 31.0% African American-RS distribution was similar for both groups. No single feature reliably identified high RS patients; however, a model accounting for age, HR expression, proliferative index (MIB1/Ki67), histology, and tumor size was generated, with receiver operator area under the curve 0.909. Fifty-six NACT patients were identified (25 African American). Of 21 cases with all relevant clinicopathology, 14 responded to NACT and the model generated high-risk RS in 14 (100%); conversely, of 16 cases generating high-risk RS, only 2 did not respond. CONCLUSIONS: Predictive modelling can identify high RS patients; this model also can identify patients likely to experience primary tumor downstaging with NACT. Until this model is validated in other datasets, we recommend that Oncotype-eligible patients undergo primary surgery with decisions regarding chemotherapy made in the adjuvant setting.

Pseudosarcomatous myofibroblastic proliferations of the genitourinary tract are genetically different from nodular fasciitis and lack USP6, ROS1 and ETV6 gene rearrangements.

AIMS: Pseudosarcomatous myofibroblastic proliferations of the genitourinary tract have a debatable relationship with inflammatory myofibroblastic tumour (generally lacking ALK rearrangement); however, they share several overlapping features with nodular fasciitis of soft tissue. As rearrangement of the USP6 gene has been recently recognised as a recurrent alteration in soft tissue nodular fasciitis, and several other alternative gene fusions have been recently recognised in inflammatory myofibroblastic tumour, the aim of this study was to investigate whether USP6, ROS1 or ETV6 rearrangements were present in these lesions (12 cases). METHODS AND RESULTS: Fluorescence in-situ hybridisation analysis was performed by the use of bacterial artificial chromosome-derived break-apart probes against USP6, ROS1, and ETV6. Two cases with adequate genetic material from recent paraffin tissue blocks were also tested by use of a solid tumour gene fusion detection assay via next-generation sequencing, targeting >50 known genes involved in recurrent fusions. None of the genitourinary pseudosarcomatous myofibroblastic proliferations was found to harbour USP6 (0/12), ROS1 (0/8) or ETV6 (0/7) rearrangements, and no gene fusions were detected in two cases studied by sequencing. CONCLUSIONS: Despite overlap in histological and immunohistochemical features between pseudosarcomatous myofibroblastic proliferation and nodular fasciitis, these tumours lack the recently recognised USP6 rearrangements that occur in nodular fasciitis, as well as alternative fusions found in ALK-negative inflammatory myofibroblastic tumours. At present, this diagnosis remains based primarily on clinical, histological and immunohistochemical features.

Pleomorphic fibroma of the skin with MDM2 immunoreactivity: A potential diagnostic pitfall.

Pleomorphic fibroma is a rare benign cutaneous neoplasm characterized by spindle-shaped cells and multinucleated giant cells scattered throughout collagenous stroma. These morphologic features can lead to diagnostic confusion, including atypical lipomatous tumor as one consideration. In contrast to atypical lipomatous tumor, previous studies have found pleomorphic fibroma to be negative for MDM2 immunohistochemical staining and MDM2 gene amplification. Here, we present a case of pleomorphic fibroma of skin with nuclear MDM2 immunoreactivity in the absence of MDM2 gene amplification, underscoring the superiority of fluorescence in situ hybridization as a diagnostic test in this differential diagnosis. The RB1 locus is also explored for differential diagnosis with pleomorphic/spindle cell lipoma and related entities.

Larger men have larger prostates: Detection bias in epidemiologic studies of obesity and prostate cancer risk.

BACKGROUND: Obesity is associated with risk of aggressive prostate cancer (PCa), but not with over-all PCa risk. However, obese men have larger prostates which may lower biopsy accuracy and cause a systematic bias toward the null in epidemiologic studies of over-all risk. METHODS: Within a cohort of 6692 men followed-up after a biopsy or transurethral resection of the prostate (TURP) with benign findings, a nested case-control study was conducted of 495 prostate cancer cases and controls matched on age, race, follow-up duration, biopsy versus TURP, and procedure date. Data on body mass index and prostate volume at the time of the initial procedure were abstracted from medical records. RESULTS: Prior to consideration of differences in prostate volume, overweight (OR = 1.41; 95%CI 1.01, 1.97), and obese status (OR = 1.59; 95%CI 1.09, 2.33) at the time of the original benign biopsy or TURP were associated with PCa incidence during follow-up. Prostate volume did not significantly moderate the association between body-size and PCa, however it did act as an inverse confounder; adjustment for prostate volume increased the effect size for overweight by 22% (adjusted OR = 1.52; 95%CI 1.08, 2.14) and for obese status by 23% (adjusted OR = 1.77; 95%CI 1.20, 2.62). Larger prostate volume at the time of the original benign biopsy or TURP was inversely associated with PCa incidence during follow-up (OR = 0.92 per 10 cc difference in volume; 95%CI 0.88, 0.97). In analyses that stratified case-control pairs by tumor aggressiveness of the case, prostate volume acted as an inverse confounder in analyses of non-aggressive PCa but not in analyses of aggressive PCa. CONCLUSIONS: In studies of obesity and PCa, differences in prostate volume cause a bias toward the null, particularly in analyses of non-aggressive PCa. A pervasive underestimation of the association between obesity and overall PCa risk may exist in the literature.

Renal cell tumors with clear cell histology and intact VHL and chromosome 3p: a histological review of tumors from the Cancer Genome Atlas database.

Clear cell renal cell carcinoma is by far the most common form of kidney cancer; however, a number of histologically similar tumors are now recognized and considered distinct entities. The Cancer Genome Atlas published data set was queried (http://cbioportal.org) for clear cell renal cell carcinoma tumors lacking VHL gene mutation and chromosome 3p loss, for which whole-slide images were reviewed. Of the 418 tumors in the published Cancer Genome Atlas clear cell renal cell carcinoma database, 387 had VHL mutation, copy number loss for chromosome 3p, or both (93%). Of the remaining, 27/31 had whole-slide images for review. One had 3p loss based on karyotype but not sequencing, and three demonstrated VHL promoter hypermethylation. Nine could be reclassified as distinct or emerging entities: translocation renal cell carcinoma (n=3), TCEB1 mutant renal cell carcinoma (n=3), papillary renal cell carcinoma (n=2), and clear cell papillary renal cell carcinoma (n=1). Of the remaining, 6 had other clear cell renal cell carcinoma-associated gene alterations (PBRM1, SMARCA4, BAP1, SETD2), leaving 11 specimens, including 2 high-grade or sarcomatoid renal cell carcinomas and 2 with prominent fibromuscular stroma (not TCEB1 mutant). One of the remaining tumors exhibited gain of chromosome 7 but lacked histological features of papillary renal cell carcinoma. Two tumors previously reported to harbor TFE3 gene fusions also exhibited VHL mutation, chromosome 3p loss, and morphology indistinguishable from clear cell renal cell carcinoma, the significance of which is uncertain. In summary, almost all clear cell renal cell carcinomas harbor VHL mutation, 3p copy number loss, or both. Of tumors with clear cell histology that lack these alterations, a subset can now be reclassified as other entities. Further study will determine whether additional entities exist, based on distinct genetic pathways that may have implications for treatment.

Evaluation and Adaptation of a Laboratory-Based cDNA Library Preparation Protocol for Retrospective Sequencing of Archived MicroRNAs from up to 35-Year-Old Clinical FFPE Specimens.

Formalin-fixed paraffin-embedded (FFPE) specimens, when used in conjunction with patient clinical data history, represent an invaluable resource for molecular studies of cancer. Even though nucleic acids extracted from archived FFPE tissues are degraded, their molecular analysis has become possible. In this study, we optimized a laboratory-based next-generation sequencing barcoded cDNA library preparation protocol for analysis of small RNAs recovered from archived FFPE tissues. Using matched fresh and FFPE specimens, we evaluated the robustness and reproducibility of our optimized approach, as well as its applicability to archived clinical specimens stored for up to 35 years. We then evaluated this cDNA library preparation protocol by performing a miRNA expression analysis of archived breast ductal carcinoma in situ (DCIS) specimens, selected for their relation to the risk of subsequent breast cancer development and obtained from six different institutions. Our analyses identified six miRNAs (miR-29a, miR-221, miR-375, miR-184, miR-363, miR-455-5p) differentially expressed between DCIS lesions from women who subsequently developed an invasive breast cancer (cases) and women who did not develop invasive breast cancer within the same time interval (control). Our thorough evaluation and application of this laboratory-based miRNA sequencing analysis indicates that the preparation of small RNA cDNA libraries can reliably be performed on older, archived, clinically-classified specimens.