A comprehensive investigation of histotype-specific microRNA and their variants in Stage I epithelial ovarian cancers.

isomiRs, the sequence-variants of microRNA, are known to be tissue and cell type specific but their physiological role is largely unknown. In our study, we explored for the first time the expression of isomiRs across different Stage I epithelial ovarian cancer (EOC) histological subtypes, in order to shed new light on their biological role in tumor growth and progression. In a multicentric retrospective cohort of tumor biopsies (n = 215) we sequenced small RNAs finding 971 expressed miRNAs, 64% of which are isomiRs. Among them, 42 isomiRs showed a clear histotype specific pattern, confirming our previously identified miRNA markers (miR192/194 and miR30a-3p/5p for mucinous and clear cell subtypes, respectively) and uncovering new biomarkers for all the five subtypes. Using integrative models, we found that the 38% of these miRNA expression alterations is the result of copy number variations while the 17% of differential transcriptional activities. Our work represents the first attempt to characterize isomiRs expression in Stage I EOC within and across subtypes and to contextualize their alterations in the framework of the large genomic heterogeneity of this tumor.

Characterization of ovarian cancer survival by histotype and stage: A nationwide study in Norway.

Contemporary population-based data on ovarian cancer survival using current subtype classifications and by surgical status are sparse. We evaluated 1-, 3-, 5- and 7-year relative (and overall) survival, and excess hazards in patients with borderline tumors or invasive epithelial ovarian cancer diagnosed 2012 to 2021 in a nationwide registry-based cohort in Norway. Outcomes were evaluated by histotype, FIGO stage, cytoreduction surgery and residual disease. Overall survival was evaluated for non-epithelial ovarian cancer. Survival of women with borderline ovarian tumors was excellent (≥98.0% 7-year relative survival). Across all evaluated invasive epithelial ovarian cancer histotypes, 7-year relative survival for cases diagnosed with stages I or II disease was ≥78.3% (stage II high-grade serous). Survival for ovarian cancers diagnosed at stage ≥III differed substantially by histotype and time since diagnosis (eg, stage III, 5-year relative survival from 27.7% [carcinosarcomas] to 76.2% [endometrioid]). Overall survival for non-epithelial cases was good (91.8% 5-year overall survival). Women diagnosed with stage III or IV invasive epithelial ovarian cancer and with residual disease following cytoreduction surgery had substantially better survival than women not operated. These findings were robust to restriction to women with high reported functional status scores. Patterns for overall survival were similar to those for relative survival. We observed relatively good survival with early stage at diagnosis even for the high grade serous histotype. Survival for patients diagnosed at stage ≥III invasive epithelial ovarian cancer was poor for all but endometrioid disease. There remains an urgent need for strategies for risk reduction and earlier detection, together with effective targeted treatments.

Profiling the immune landscape in mucinous ovarian carcinoma.

OBJECTIVE: Mucinous ovarian carcinoma (MOC) is a rare histotype of ovarian cancer, with low response rates to standard chemotherapy, and very poor survival for patients diagnosed at advanced stage. There is a limited understanding of the MOC immune landscape, and consequently whether immune checkpoint inhibitors could be considered for a subset of patients. METHODS: We performed multicolor immunohistochemistry (IHC) and immunofluorescence (IF) on tissue microarrays in a cohort of 126 MOC patients. Cell densities were calculated in the epithelial and stromal components for tumor-associated macrophages (CD68+/PD-L1+, CD68+/PD-L1-), T cells (CD3+/CD8-, CD3+/CD8+), putative T-regulatory cells (Tregs, FOXP3+), B cells (CD20+/CD79A+), plasma cells (CD20-/CD79a+), and PD-L1+ and PD-1+ cells, and compared these values with clinical factors. Univariate and multivariable Cox Proportional Hazards assessed overall survival. Unsupervised k-means clustering identified patient subsets with common patterns of immune cell infiltration. RESULTS: Mean densities of PD1+ cells, PD-L1- macrophages, CD4+ and CD8+ T cells, and FOXP3+ Tregs were higher in the stroma compared to the epithelium. Tumors from advanced (Stage III/IV) MOC had greater epithelial infiltration of PD-L1- macrophages, and fewer PD-L1+ macrophages compared with Stage I/II cancers (p = 0.004 and p = 0.014 respectively). Patients with high epithelial density of FOXP3+ cells, CD8+/FOXP3+ cells, or PD-L1- macrophages, had poorer survival, and high epithelial CD79a + plasma cells conferred better survival, all upon univariate analysis only. Clustering showed that most MOC (86%) had an immune depleted (cold) phenotype, with only a small proportion (11/76,14%) considered immune inflamed (hot) based on T cell and PD-L1 infiltrates. CONCLUSION: In summary, MOCs are mostly immunogenically 'cold', suggesting they may have limited response to current immunotherapies.

Gastric (gastrointestinal)-type endometrial adenocarcinoma presenting as a solitary endometrial polyp: a case report and literature review on a novel and potentially aggressive endometrial cancer histotype.

Gastric-type carcinoma of the endometrium is a rare endometrial cancer histotype, recently introduced in the 2020 WHO classification of the female genital tract tumors. Clinico-pathological features, as well as treatment strategies for this rare histotype, are not fully defined. We herein present an unusual case of endometrial carcinoma with mucinous features arising in a 58-year-old menopausal woman. Morphological features of the present case as well as immunohistochemical profile were consistent with gastrointestinal differentiation. Therefore, after clinical and imaging studies ruled out the possibility of a metastatic origin, a final diagnosis of gastric-type carcinoma of the endometrium was rendered.

The impact of the histological classification of ampullary carcinomas on long-term outcomes after pancreaticoduodenectomy: a single tertiary referral center evaluation.

PURPOSE: Ampullary carcinomas (ACs) are classified as pancreatobiliary (Pb-AC), intestinal (Int-AC), or mixed (Mixed-AC). The influencing role of AC subtypes on long-term outcomes is still matter of debate. Aim of this study is to evaluate the prognostic role of the three histological variants on the overall (OS) and disease-free survival (DFS) after pancreaticoduodenectomy(PD). METHODS: All PDs for AC between 2004 and 2020 were included. Patients were classified according to the histological feature in Pb-AC, Int-AC, and Mixed-AC. Five-year OS and DFS were compared among the subtypes. Additionally, the prognostic role of the histological classification on OS and DFS was evaluated. RESULTS: Fifty-six (48.7%) Pb-ACs, 53 (46.1%) Int-ACs, and 6 (5.2%) Mixed-ACs were evaluated. A poorer 5-year OS was evidenced for the Pb-AC group (54.1%) as compared to the Int-AC cohort (80.7%) (p = 0.03), but similar to the Mixed-AC population (33%) (p = 0.45). Pb-AC presented a worse 5-year DFS (42.3%) in comparison to the Int-AC (74.8%) (p = 0.002), while no difference was evidenced in comparison to the Mixed-AC (16.7%) (p = 0.51). At the multivariate analysis, the Pb-/Mixed-AC histotype was recognized as negative prognostic factor for both OS (OR: 2.29, CI: 1.05-4.98; p = 0.04) and DFS (OR: 2.17, CI: 1-4.33; p = 0.02). CONCLUSION: Histological subtypes of AC play a relevant role in long-term outcomes after PD. Pb-ACs and Mixed-ACs show a more aggressive tumor biology and a consequent worse survival as compared to the Int-AC subtype.

TCGA Molecular Prognostic Groups of Endometrial Carcinoma: Current Knowledge and Future Perspectives.

The four TCGA-based molecular prognostic groups of endometrial carcinoma (EC), i.e., POLE-mutant, mismatch repair (MMR)-deficient, p53-abnormal, and "no specific molecular profile" (NSMP), have recently been integrated into ESGO-ESTRO-ESP guidelines. The POLE-mutant and MMR-deficient groups are associated with high mutational load, morphological heterogeneity, and inflammatory infiltration. These groups are frequent in high-grade endometrioid, undifferentiated/dedifferentiated, and mixed histotypes. POLE-mutant ECs show good prognosis and do not require adjuvant treatment, although the management of cases at stage >II is still undefined. MMR-deficient ECs show intermediate prognosis and are currently substratified based on clinicopathological variables, some of which might not have prognostic value. These groups may benefit from immunotherapy. P53-mutant ECs are typically high-grade and often morphologically ambiguous, accounting for virtually all serous ECs, most carcinosarcomas and mixed ECs, and half of clear-cell ECs. They show poor prognosis and are treated with chemoradiotherapy; a subset may benefit from HER2 inhibitors or PARP inhibitors. The NSMP group is the most frequent TCGA group; its prognosis is highly variable and affected by clinicopathological/molecular factors, most of which are still under evaluation. In conclusion, the TCGA classification has improved diagnosis, risk stratification, and management of EC. Further studies are needed to resolve the points of uncertainty that still exist.

Metaplastic breast cancer: Prognostic and therapeutic considerations.

INTRODUCTION: Metaplastic breast cancer (MBC) is a rare condition of breast tumor with different subtypes, considered a disease with worse prognosis; treatments and survival are often unclear and conflicting. METHODS: We consecutively collected 153 primary MBCs of different subtypes. Breast surgery, neoadjuvant or adjuvant treatment, clinic-pathological factors, number and type of events during follow-up were considered to evaluate overall survival (OS) and invasive disease-free survival (IDFS). RESULTS: The majority of MBC was triple-negative (TN) subtype (88.7%), G3 (95.3%), pN0 (70.6%), and with high levels of Ki-67 (93.5%). For OS and IDFS, no significant associations were seen between the different MBC subtypes. The matched triple-negative MBC (TNMBC) and ductal TNBC cohorts had similar prognosis both in terms of OS (p = .411) and IDFS (p = .981). We observed a positive trend for TNMBC patients treated in the adjuvant setting with the cyclofosfamide, methotrexate, 5-fluorouracil protocol for better OS (p = .090) and IDFS (p = .087). A poor or absent response rate was observed in the neoadjuvant setting. CONCLUSION: Our results demonstrate that metaplastic and ductal breast cancers with TN phenotype are similar in terms of overall and disease-free survival. Metaplastic cancers are poorly responsive to neoadjuvant treatment, and in the absence of novel targeted therapies, surgical treatment remains the first choice.

Core needle biopsy versus incisional biopsy for differentiation of soft-tissue sarcomas: A systematic review and meta-analysis.

BACKGROUND: Controversies exist regarding the biopsy technique of choice for the accurate diagnosis of soft-tissue sarcoma (STS). The objective of this systematic review and meta-analysis was to compare the diagnostic accuracy of core needle biopsy (CNB) versus incisional biopsy (IB) in STS with reference to the final histopathological result. METHODS: Studies regarding the diagnostic accuracy of CNB and IB in detecting STS were searched systematically in the MEDLINE and EMBASE databases. Estimates of sensitivity and specificity with associated 95% CIs for diagnostic accuracy were calculated. The risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies version 2 (QUADAS-2). RESULTS: A total of 17 studies comprising 2680 patients who underwent 1582 CNBs and 241 IBs with subsequent tumor resection met the inclusion criteria. The sensitivity and specificity of CNB and IB to detect the dignity of lesions were 97% (95% CI, 95%-98%) and 99% (95% CI, 97%-99%), respectively, and 96% (95% CI, 92%-99%) and 100% (95% CI, 94%-100%), respectively. Estimates of the sensitivity and specificity of CNB and IB to detect the STS histotype were 88% (95% CI, 86%-90%) and 77% (95% CI, 72%-81%), respectively, and 93% (95% CI, 87%-97%) and 65% (95% CI, 49%-78%), respectively. Patients who underwent CNB had a significantly reduced risk of complications compared with patients who underwent IB (risk ratio, 0.14; 95% CI, 0.03-0.56 [P ≤ .01). Quality assessment of studies revealed a high risk of bias. CONCLUSIONS: CNB has high accuracy in diagnosing the dignity of lesions and STS histotype in patients with suspected STS with fewer complications compared with IB. Therefore, CNB should be regarded as the primary biopsy technique.

Dental morphology and microstructure of the Prickly Dogfish Oxynotus bruniensis (Squaliformes: Oxynotidae).

This study describes and illustrates the jaws, teeth, and tooth microstructure of the Prickly Dogfish Oxynotus bruniensis. Detailed accounts of the dental morphology of O. bruniensis are rare and have not addressed the tissue arrangement or microstructure of the teeth. These features are documented and discussed in the contexts of interspecific comparisons with other elasmobranchs and the dietary specialization of O. bruniensis. The overall tooth morphology of O. bruniensis is similar to those of other closely related members in the order Squaliformes, as is the tissue arrangement, or histotype. Oxynotus bruniensis exhibits a simplified enameloid microstructure, which we compare with previously documented enameloid microstructures of other elasmobranchs. Though subtle interspecific differences in dental characters are documented, neither overall tooth morphology nor histotype and microstructure are unique to O. bruniensis. We conclude that in the case of O. bruniensis, dietary specialization is facilitated by behavioral rather than morphological specialization.

Evolutionary trajectories of tooth histology patterns in modern sharks (Chondrichthyes, Elasmobranchii).

During their evolutionary history, modern sharks developed different tooth mineralization patterns that resulted in very distinct histological patterns of the tooth crown (histotypes). To date, three different tooth histotypes have been distinguished: (i) orthodont teeth, which have a central hollow pulp cavity in the crown, encapsulated by a prominent layer of dentine (orthodentine); (ii) pseudoosteodont teeth, which have their pulp cavities secondarily replaced by a dentinal core of porous dentine (osteodentine), encased by orthodentine; and (iii) osteodont teeth, which lack orthodentine and the whole tooth crown of which consists of osteodentine. The aim of the present study was to trace evolutionary trends of tooth mineralization patterns in modern sharks and to find evidence for the presence of phylogenetic or functional signals. High resolution micro-computed tomography images were generated for the teeth of members of all nine extant shark orders and the putative stem group †Synechodontiformes, represented here by three taxa, to examine the tooth histology non-destructively. Pseudoosteodonty is the predominant state among modern sharks and represents unambiguously the plesiomorphic condition. Orthodonty evolved several times independently in modern sharks, while the osteodont tooth histotype is only developed in lamniform sharks. The two shark orders Heterodontiformes and Pristiophoriformes showed highly modified tooth histologies, with Pristiophorus exhibiting a histology only known from batomorphs (i.e. rays and skates), and Heterodontus showing a histological difference between anterior and posterior teeth, indicating a link between its tooth morphology, histology and durophagous lifestyle. The tooth histotype concept has proven to be a useful tool to reflect links between histology, function and its taxonomic value for distinct taxa; however, a high degree of variation, especially in the pseudoosteodont tooth histotype, demonstrates that the current histotype concept is too simplistic to fully resolve these relationships. The vascularization pattern of the dentine might offer new future research pathways for better understanding functional and phylogenetic signals in the tooth histology of modern sharks.

Predictors of survival trajectories among women with epithelial ovarian cancer.

OBJECTIVE: Although ovarian cancer is a deadly disease, approximately a third of women survive ≥9 years after diagnosis. The factors associated with achieving long-term survival are not well understood. In this study, data from the Surveillance, Epidemiology, and End Results (SEER) program were used to determine predictors of survival trajectories among women with epithelial ovarian cancer and across histotype (high-grade serous carcinoma (HGSC) and non-HGSC). METHODS: Data on 35,868 women diagnosed with epithelial ovarian cancer in 2004-2016 were extracted from SEER. Extended Cox proportional hazards regression was used to estimate overall and histotype-specific associations between patient and tumor characteristics and all-cause mortality within each survival time (t) interval (t < 3, 3 ≤ t < 6, 6 ≤ t < 9, and 9 ≤ t < 13 years). RESULTS: Age at diagnosis, marital status, race/ethnicity, stage, and surgery were more strongly associated with mortality in the short-term survival period, and these associations waned with increasing survival time. Exceptions to this pattern were age >70 years at diagnosis, where a high risk of mortality was observed in both the t < 3 and t ≥ 9 year time periods, and non-Hispanic Asian/Pacific Islanders, where a more pronounced inverse association with mortality was observed in t ≥ 9 years after diagnosis. Similar associations were observed for HGSC, although the waning effect was not apparent for most characteristics. Mortality associations for non-HGSC were more pronounced for stage and race/ethnicity, primarily for non-Hispanic Asian/Pacific Islanders. CONCLUSIONS: Most patient and tumor characteristics were more strongly associated with mortality in the years following diagnosis, but have declining impact with increasing survival time. Given this waning effect, it is critical to identify factors impacting risk of mortality as ovarian cancer patients advance through the survival trajectory.

Clinicopathological parameters and survival of invasive epithelial ovarian cancer by histotype and disease stage.

Aim: To investigate clinicopathological parameters and histotype-specific survival of epithelial ovarian cancer by stage using the 2014 WHO classification. Patients & methods: Patients were obtained from the SEER database. Multivariate and univariate Cox regression analyses were applied to assess survival outcomes. Results: Irrespective of stages, low-grade serous and endometrioid had the best survival rates. In localized and regional stages, the poorest survival rates were detected for carcinosarcoma and malignant Brenner tumors, but in distant stage, the worst prognoses were observed in mucinous, clear cell and carcinosarcoma (p < 0.05 for all). Conclusion: Our study displayed significant differences in clinicopathological parameters and histotype-specific survival by stages that reflected current consensus on histotype classification and pathogenesis of epithelial ovarian cancer.

Gastric Adenocarcinomas in Central Tunisia: Evolution Specificities through Two Decades and Relation with Helicobacter pylori.

INTRODUCTION: In developed countries, authors have reported variations over time in the seat and histological type of gastric adenocarcinomas, which were explained by Helicobacter pylori infection (HPI) incidence changes. In North-African countries and the Arabic world, epidemiological changes in gastric adenocarcinomas are still unknown. Our study aims to explore and to describe those changes in central Tunisia. MATERIALS AND METHODS: This is a retrospective observational and descriptive study including 876 cases based on the National Central Tunisian Register of Cancers over a period of 21 years. Two groups were formed and compared (group A: 337 patients from 1995 to 2005; group B: 539 patients from 2006 to 2015). RESULTS: HPI decreased from 32.6% in group A to 11.2% in group B (p < 0.05). Signet ring cell carcinomas increased in 2 decades from 14% in group A to 36% in group B (p < 0.05). Proximal cancers were 16.61% in group A and increased to 19.66% in group B (p = 0.3). Total gastrectomy rate was 10.4% in group A versus 23.2% in group B (p < 0.05). CONCLUSION: This study has shown a significant increase of signet ring cell carcinomas with a simultaneous decrease in HPI in the last decade in central Tunisia.

Long-term mortality among women with epithelial ovarian cancer: a population-based study in British Columbia, Canada.

OBJECTIVES: Among women with epithelial ovarian cancer (EOC), histotype is one of the major prognostic factors. However, few data are available on histotype- specific survival and mortality estimates among these patients. We therefore examined survival and causes of death among women with EOC by histotype. METHODS: A population- based cohort including all ovarian cancer patients diagnosed in British Columbia (BC) between 1990 and 2014 was built using population-based administrative datasets. We compared causes of death within histotypes, by age at diagnosis, BRCA status, and time since diagnosis. RESULTS: A total of 6975 women were identified as having been diagnosed with EOC between 1990 and 2014 in BC. The most common cause of death among these women was ovarian cancer until 10 years post diagnosis when other causes surpassed ovarian cancer as the leading cause of death. Among women with serous EOCs, ovarian cancer was the leading cause of death 12 years after diagnosis, whereas ovarian cancer was the leading cause of death for 8 years among women with non- serous EOCs. Among women with serous EOCs, ovarian cancer was the leading cause of death for 12 years among younger women (< 60 years of age) compared to 8 years among women > = 60 years of age, and those with BRCA mutations were more likely to die from ovarian cancer than those without a BRCA mutation. CONCLUSIONS: Within 10 years from diagnosis, ovarian cancer is the leading cause of death among women diagnosed with EOC.

Characteristics and outcome of the COEUR Canadian validation cohort for ovarian cancer biomarkers.

BACKGROUND: Ovarian carcinoma is the most lethal gynecological malignancy due to early dissemination and acquired resistance to platinum-based chemotherapy. Reliable markers that are independent and complementary to clinical parameters are needed to improve the management of patients with this disease. The Canadian Ovarian Experimental Unified Resource (COEUR) provides researchers with biological material and associated clinical data to conduct biomarker validation studies. Using standards defined by the Canadian Tissue Repository Network (CTRNet), we have previously demonstrated the quality of the biological material from this resource. Here we describe the clinical characteristics of the COEUR cohort. METHODS: With support from 12 Canadian ovarian cancer biobanks in Canada, we created a central retrospective cohort comprised of more than 2000 patient tissue samples with associated clinical data, including 1246 high-grade serous, 102 low-grade serous, 295 endometrioid, 259 clear cell and 89 mucinous carcinoma histotypes. A two-step reclassification process was applied to assure contemporary histological classification (histotyping). For each histotypes individually, we evaluated the association between the known clinico-pathological parameters (stage, cytoreduction, chemotherapy treatment, BRCA1 and BRCA2 mutation) and patient outcome by using Kaplan-Meier and Cox proportional hazard regression analyses. RESULTS: The median follow-up time of the cohort was 45 months and the 5-year survival rate for patients with high-grade serous carcinomas was 34%, in contrast to endometrioid carcinomas with 80% at 5 years. Survival profiles differed by histotype when stratified by stage or cytoreduction. Women with mucinous or clear cell carcinomas at advanced stage or with non-optimally debulked disease had the worst outcomes. In high-grade serous carcinoma, we observed significant association with longer survival in women harboring BRCA1 or BRCA2 mutation as compared to patients without detectable mutation. CONCLUSIONS: Our results show the expected survival rates, as compared with current literature, in each histotype suggesting that the cohort is an unbiased representation of the five major histotypes. COEUR, a one stop comprehensive biorepository, has collected mature outcome data and relevant clinical data in a comprehensive manner allowing stratified analysis.

Inter-pathologist and pathology report agreement for ovarian tumor characteristics in the Nurses' Health Studies.

BACKGROUND: Grade and histotype of ovarian carcinomas are often used as surrogates of molecular subtypes. We examined factors affecting pathologists' reproducibility in two prospective studies. METHODS: Two pathologists independently reviewed slides from 459 incident ovarian cancers in the Nurses' Health Study (NHS) and NHSII. We described agreement on tumor characteristics using percent agreement and Cohen's standard kappa (κ) coefficients. We used logistic regression, with disagreement as the outcome, to evaluate the contribution of case and tumor characteristics to agreement. RESULTS: Inter-rater agreement was 95% (κ = 0.81) for carcinoma versus borderline, 89% (κ = 0.58) for grade and 85% (κ = 0.71) for histotype. Inter-rater grading disagreement was higher for non-serous histotypes (OR = 4.66, 95% CI 2.09-10.36) and lower for cancers with bizarre atypia (OR = 0.13, 95% CI 0.04-0.38). Agreement with original pathology reports was 94% (κ = 0.73) for carcinoma versus borderline, 78% (κ = 0.60) for histotype, and 79% (κ = 0.24) for grade. Grading disagreement was significantly lower for tumors with 'solid, pseudoendometrioid or transitional' (SET) architecture (OR = 0.08, 95%CI 0.01-0.84). Date of original diagnosis, hospital type, number of slides available for review, tumor stage, and slide quality were not related to agreement. CONCLUSION: Overall, inter-rater agreement for tumor type and grade for archival tissue specimens was good. Agreement between the consensus review and original pathology reports was lower. Factors contributing to grading disagreement included non-serous histotype, absence of bizarre atypia, and absence of SET architecture.

Histotype classification of ovarian carcinoma: A comparison of approaches.

OBJECTIVE: Major changes in the classification of ovarian carcinoma histotypes occurred over the last two decades, resulting in the current 2014 World Health Organization (WHO) diagnostic criteria that recognize five principal histotypes: high-grade serous, low-grade serous, endometrioid, clear cell, and mucinous carcinoma. We assessed the impact of these guidelines and use of immunohistochemical (IHC) markers on classification of ovarian carcinomas in existing population-based studies. METHODS: We evaluated histotype classification for 2361 ovarian carcinomas diagnosed between 1999 and 2009 from two case-control studies using three approaches: 1. pre-2014 WHO ("historic") histotype; 2. Standardized review of pathology slides using the 2014 WHO criteria alone; and 3. An integrated IHC assessment along with the 2014 WHO criteria. We used Kappa statistics to assess agreement between approaches, and Kaplan-Meier survival curves and Cox proportional hazards models to evaluate mortality. RESULTS: Compared to the standardized pathologic review histotype, agreement across approaches was high (kappa = 0.892 for historic, and 0.849 for IHC integrated histotype), but the IHC integrated histotype identified more low-grade serous carcinomas and a subset of endometrioid carcinomas that were assigned as high-grade serous (n = 25). No substantial differences in histotype-specific mortality were observed across approaches. CONCLUSIONS: Our findings suggest that histotype assignment is fairly consistent regardless of classification approach, but that progressive improvements in classification accuracy for some less common histotypes are achieved with pathologic review using the 2014 WHO criteria and with IHC integration. We additionally recommend a classification scheme to fit historic data into the 2014 WHO categories to answer histotype-specific research questions.

Confirmation of ProMisE: A simple, genomics-based clinical classifier for endometrial cancer.

BACKGROUND: Classification of endometrial carcinomas (ECs) by morphologic features is irreproducible and imperfectly reflects tumor biology. The authors developed the Proactive Molecular Risk Classifier for Endometrial Cancer (ProMisE), a molecular classification system based on The Cancer Genome Atlas genomic subgroups, and sought to confirm both feasibility and prognostic ability in a new, large cohort of ECs. METHODS: Immunohistochemistry (IHC) for the presence or absence of mismatch repair (MMR) proteins (to identify MMR deficiency [MMR-D]), sequencing for polymerase-ɛ (POLE) exonuclease domain mutations (POLE EDMs), and IHC for tumor protein 53 (p53) (wild type vs null/missense mutations; p53 wt and p53 abn, respectively) were performed on 319 new EC samples. Subgroups were characterized and assessed relative to outcomes. The prognostic ability of ProMisE was compared with that of current risk-stratification systems (European Society of Medical Oncology [ESMO]). RESULTS: ProMisE decision-tree classification achieved categorization of all cases and identified 4 prognostic subgroups with distinct overall, disease-specific, and progression-free survival (P < .001). Tumors with POLE EDMs had the most favorable prognosis, and those with p53 abn the worst prognosis, and separation of the 2 middle survival curves (p53 wt and MMR-D) was observed. There were no significant differences in survival between the ESMO low-risk and intermediate-risk groups. ProMisE improved the ability to discriminate outcomes compared with ESMO risk stratification. There was substantial overlap (89%) between the p53 abn and high-risk ESMO subgroups; but, otherwise, there were no predictable associations between molecular and ESMO risk groups. CONCLUSIONS: Molecular classification of ECs can be achieved using clinically applicable methods and provides independent prognostic information beyond established clinicopathologic risk factors available at diagnosis. Consistent, biologically relevant categorization enables stratification for clinical trials and/or targeted therapy, identification of women who are at increased risk of having Lynch syndrome, and may guide clinical management. Cancer 2017;123:802-13. © 2016 American Cancer Society.

Tubal ligation and ovarian cancer risk in a large cohort: Substantial variation by histological type.

Histopathological and molecular studies suggest that different histological subtypes (histotypes) of ovarian cancer have different aetiologies. Few studies have been large enough to explore reliably the effect of tubal ligation (sterilization), which has been associated with a reduced overall risk of ovarian cancer, on different tumour histotypes. In a prospective study of 1.1 million UK women without prior cancer or bilateral oophorectomy, 8,035 ovarian cancers occurred during mean follow-up of 13.8 years. Using a Cox proportional hazards model, we estimated adjusted relative risks of ovarian cancer associated with tubal ligation. Overall, there was substantial heterogeneity in tumour risk associated with tubal ligation for the four main histotypes, serous, endometrioid, mucinous and clear cell (heterogeneity: p < 0.0001). For serous tumours, the most common histotype (n = 3,515), risks differed significantly between high-grade (RR: 0.77, 95% CI: 0.67-0.89) and low-grade tumours (RR: 1.13, 95% CI: 0.89-1.42); heterogeneity: p = 0.007. Relative risks were almost halved for endometrioid (n = 690, RR: 0.54, 95% CI: 0.43-0.69) and clear cell tumours (n = 401, RR: 0.55, 95% CI: 0.39-0.77), but there was no association between tubal ligation and mucinous tumours (n = 836, RR: 0.99, 95% CI: 0.84-1.18). For the main tumour histotypes we found little variation of risk by timing of tubal ligation. The significant differences by tumour histotype are unlikely to be due to confounding and are consistent with hypotheses that high-grade and low-grade serous tumours have different origins, and that some endometrioid and clear cell tumours might arise from cells and/or carcinogens travelling through the fallopian tubes.

Significant frequency of MSH2/MSH6 abnormality in ovarian endometrioid carcinoma supports histotype-specific Lynch syndrome screening in ovarian carcinomas.

AIMS: Lynch syndrome screening in ovarian carcinoma is controversial. The aim of this study was to assess the frequency of deficient mismatch repair (dMMR) protein in a retrospective cohort enriched for non-high-grade serous carcinomas and its association with outcome within histological types. METHODS AND RESULTS: Tissue microarrays representing 612 ovarian carcinomas were tested for mismatch repair proteins (MLH1, PMS2, MSH2, and MSH6) by immunohistochemistry. dMMR was detected in 13.8% of endometrioid and 2.4% of clear cell carcinomas, but not in other histological types. Within endometrioid carcinomas, 11 of 25 dMMR cases showed abnormal MLH1/PMS2, 10 cases showed abnormal MSH2/MSH6, and four cases showed only abnormal MSH6, indicating that at least 7.7% of endometrioid carcinomas have dMMR probably related to Lynch syndrome. The four dMMR clear cell carcinomas showed abnormal MSH2/MSH6 in three cases and only abnormal MSH6 in one case, all probably related to Lynch syndrome. Within endometrioid carcinomas, dMMR was significantly associated with age <50 years, synchronous endometrial endometrioid carcinoma, a higher CA125 level at diagnosis, higher FIGO grade, absence of ARID1A, and at least 20 CD8-positive intraepithelial lymphocytes per high-power field, but was not associated with cancer-specific death. Age <50 years, higher CA125 levels at diagnosis and at least 20 CD8-positive intraepithelial lymphocytes per high-power field remained significant after adjustment for multiple testing, but their sensitivity for identifying dMMR remained insufficient. CONCLUSION: Our data support the policy of histotype-specific Lynch syndrome screening in ovarian carcinoma confined to endometrioid and clear cell carcinomas.