TCGA molecular classification in endometriosis-associated ovarian carcinomas: Novel data on clear cell carcinoma

Molecular features for timely cancer diagnosis and treatment - tumors of the ovary, fallopian tube and endometrium

Gynecologic pathology has moved, within only a few years, from being a diagnostic area devoid of molecular testing into a diagnostic discipline in which such analyses are becoming routine. The direct relevance of molecular characterization to the choice of treatment of patients with carcinomas originating in both the uterus and adnexae makes it likely that such testing will only expand along with our understanding of the molecular make-up of these tumors. As a consequence, gynecologic pathologists have become an integral part of patient management, rather than lab personnel providing external services.In parallel, molecular testing is expanding as a tool for diagnosing rare tumors affecting these organs, including soft tissue tumors, sex cord-stromal tumors and germ cell tumors, as well as other rare entities. Increased knowledge in this area bears directly on the ability to diagnose these tumors in a reproducible manner, as well as recognize and consult on genetic diseases. Hopefully, despite the inherent difficulty in studying rare cancers, it will also translate into new therapeutic options for the malignant ones among these rare cancers.

Derivation and validation of a nomogram based on clinical characteristics to diagnose endometriosis associated ovarian cancer preoperatively

PURPOSE

The preoperative diagnosis of endometriosis associated ovarian cancer (EAOC) remains challenging for lack of effective diagnostic biomarker. We aimed to study clinical characteristics and develop a nomogram for diagnosing EAOC before surgery.

METHODS

A total of 87 patients with EAOC and 348 patients with ovarian endometrioma (OEM) were enrolled in our study. Least absolute shrinkage and selection operator (LASSO) regression and Logistic regression were utilized to select variables and construct the prediction model. The performance of the model was assessed using receiver operating characteristic (ROC) analyses and calibration plots, while decision curve analyses (DCAs) were conducted to assess clinical value. Bootstrap resampling was used to evaluated the stability of the model in the derivation set.

RESULTS

The EAOC patients were older compared to the OEM patients (46.41 ± 9.62 vs. 36.49 ± 8.09 year, P < 0.001) and proportion of postmenopausal women was higher in EAOC group than in the OEM group (34.5 vs. 1.5%, P < 0.001). Our prediction model, which included age at diagnosis, tumor size, cancer antigen (CA) 19-9 and risk of ovarian malignancy algorithm (ROMA), demonstrated an area under the curve (AUC) of 0.858 (95% confidence interval (CI): 0.795-0.920) in the derivation set (N = 304) and an AUC of 0.870 (95% CI: 0.779-0.961) in the validation set (N = 131). The model fitted both the derivation (Hosmer-Lemeshow test (HL) chi-square = 12.600, P = 0.247) and the validation (HL chi-square = 8.210, P = 0.608) sets well.

CONCLUSION

Compared to patients with OEM, those with EAOC exhibited distinct clinical characteristics. Our four-variable prediction model demonstrated excellent performance in both the derivation and validation sets, suggesting its potential to assist with preoperative diagnosis of EAOC.

Clinical Outcome and Morphology-Based Analysis of p53 Aberrant and Mismatch Repair Protein-Deficient Ovarian Clear Cell Carcinoma and Their Association With p16, HER2, and PD-L1 Expression

OBJECTIVES

We studied the prevalence and prognostic significance of mismatch repair deficient (MMRD) and p53 aberrant ovarian clear cell carcinoma (CCO) and their association with other prognostic and theranostic biomarkers (p16, HER2, PD-L1). We also aimed to identify morphologic features to serve as screening tools for immunohistochemical testing for these biomarkers.

METHODS

Tissue microarrays with 3-mm cores from 71 pure CCOs were immunostained with PMS2, MSH6, p53, p16, HER2, and PD-L1. Expression status was correlated with tumor recurrence/disease progression and survival. It was also correlated with morphologic features (tumor size, nuclear grade, tumor architecture, mitotic activity, presence of endometriosis, tumor budding, and tumor inflammation).

RESULTS

p53 aberrant tumors were associated with shorter overall and recurrence-free survivals (P = .002 and P = .01, respectively). In multivariate analysis, p53 aberrant status and tumor stage were independently associated with recurrence/disease progression (hazard ratio [HR] = 3.31, P = .037 and HR = 1.465, P = .004, respectively). p53 aberrant status was associated with tumor budding (P = .037). MMRD, p16, HER2, and PD-L1 expression had no prognostic significance. HER2 and PD-L1 were expressed in 56% and 35% of tumors, respectively. MMRD was associated with tumor expression of PD-L1 (P > .05) but not with tumor inflammation.

CONCLUSIONS

Aberrant p53 in CCO is infrequent but associated with poor prognosis independent of stage. Presence of tumor budding could be a screening tool for p53 testing. High prevalence of HER2 and PD-L1 expression indicates the eligibility of patients with CCO for ongoing clinical trials using these therapeutic targets.

Microsatellite instability in non-endometrioid ovarian epithelial tumors: a study of 400 cases comparing immunohistochemistry, PCR, and NGS based testing with mutation status of MMR genes

Testing of microsatellite instability is not only used as a triage for possible Lynch syndrome, but also to predict immunotherapy treatment response. The aim of this study was to assess the frequency of mismatch repair deficiency (MMR-D)/microsatellite instability (MSI) in 400 cases of non-endometrioid ovarian tumors (high-grade serous, low-grade serous, mucinous and clear cell), to compare different methodological approaches of testing, and to assess the optimal approach for next generation sequencing (NGS) MSI testing. For all tumors, we evaluated immunohistochemical (IHC) expression of MMR proteins and assessed microsatellite markers by PCR-based method. Except for high-grade serous carcinoma, we correlated the findings of IHC and PCR with NGS-based MSI testing. We compared the results with somatic and germline mutation in MMR genes. Among the whole cohort, seven MMR-D cases, all clear cell carcinomas (CCC), were found. On PCR analysis, 6 cases were MSI-high and one was MSS. In all cases, mutation of an MMR gene was found; in 2 cases, the mutation was germline (Lynch syndrome). An additional 5 cases with a mutation in MMR gene(s) with MSS status and without MMR-D were identified. We further utilized sequence capture NGS for MSI testing. Employing 53 microsatellite loci provided high sensitivity and specificity. Our study shows that MSI occurs in 7% of CCC while it is rare or absent in other nonendometrioid ovarian neoplasms. Lynch syndrome was present in 2% of patients with CCC. However, some cases with MSH6 mutation can evade all testing methods, including IHC, PCR, and NGS-MSI.

Endometriosis in clear cell and endometrioid carcinoma ovary: its impact on clinicopathological characteristics and survival outcomes

Background

Malignant transformation in endometriosis was first described by Sampson in 1925. There is now sufficient evidence of its association specifically with endometrioid (EOC) and clear cell ovarian cancer (CCOC). Whether endometriosis-associated ovarian cancer (EAOC) is a distinct clinicopathological entity from non-endometriosis-associated ovarian cancer (NEAOC) remains uncertain.

Objectives

This study aimed to assess the impact of endometriosis on clinical characteristics and survival outcomes in EOC and CCOC.

Methods

This is a retrospective single-institution analysis of patients diagnosed with CCOC AND EOC between 2010 and 2021. Demographic and clinical presentation data were obtained from medical records. Patients were followed up till March 2023. Statistical analysis was done using the IBM SPSS Statistics 20 Windows.

Results

Of the 77 cases of CCOC and EOC ovary, 38 had histopathologically proven endometriosis. There was no difference in age (51.62 and 50.05 years, respectively), body mass index, parity, menopausal status and CA 125 levels at presentation. Ascites was more frequent in the absence of endometriosis (30% versus 8.1%, p = 0.015). However, this did not translate to a statistical difference in the stage, with the majority presenting in the early stage. (94% versus 83%). All 78 patients underwent primary cytoreduction with equal rates of optimal resection.There was no difference in the mean disease-free interval between EAOC and NEAOC (107.6 and 109.4 months, p 0.484). Recurrences were predominantly pelvic in both groups. The disease-specific survival was 111.7 and 120.1 months, respectively, with and without endometriosis. This was however not statistically significant (p 0.751).

Conclusion

In the Indian population, endometriosis did not have any impact on the age at presentation, CA 125 levels, stage of the disease and survival outcomes in EOC and CCOC ovary.

A comprehensive molecular analysis of 113 primary ovarian clear cell carcinomas reveals common therapeutically significant aberrations

BACKGROUND

Molecular aberrations occurring in primary ovarian clear cell carcinoma (OCCC) can be of diagnostic, predictive, and prognostic significance. However, a complex molecular study including genomic and transcriptomic analysis of large number of OCCC has been lacking.

METHODS

113 pathologically confirmed primary OCCCs were analyzed using capture DNA NGS (100 cases; 727 solid cancer related genes) and RNA-Seq (105 cases; 147 genes) in order to describe spectra and frequency of genomic and transcriptomic alterations, as well as their prognostic and predictive significance.

RESULTS

The most frequent mutations were detected in genes ARID1A, PIK3CA, TERTp, KRAS, TP53, ATM, PPP2R1A, NF1, PTEN, and POLE (51,47,27,18,13,10,7,6,6, and 4%, respectively). TMB-High cases were detected in 9% of cases. Cases with POLE^mut and/or MSI-High had better relapse-free survival. RNA-Seq revealed gene fusions in 14/105 (13%) cases, and heterogeneous expression pattern. The majority of gene fusions affected tyrosine kinase receptors (6/14; four of those were MET fusions) or DNA repair genes (2/14). Based on the mRNA expression pattern, a cluster of 12 OCCCs characterized by overexpression of tyrosine kinase receptors (TKRs) AKT3, CTNNB1, DDR2, JAK2, KIT, or PDGFRA (p < 0.00001) was identified.

CONCLUSIONS

The current work has elucidated the complex genomic and transcriptomic molecular hallmarks of primary OCCCs. Our results confirmed the favorable outcomes of POLE^mut and MSI-High OCCC. Moreover, the molecular landscape of OCCC revealed several potential therapeutical targets. Molecular testing can provide the potential for targeted therapy in patients with recurrent or metastatic tumors.

p53 and ovarian carcinoma survival: an Ovarian Tumor Tissue Analysis consortium study

Our objective was to test whether p53 expression status is associated with survival for women diagnosed with the most common ovarian carcinoma histotypes (high-grade serous carcinoma [HGSC], endometrioid carcinoma [EC], and clear cell carcinoma [CCC]) using a large multi-institutional cohort from the Ovarian Tumor Tissue Analysis (OTTA) consortium. p53 expression was assessed on 6,678 cases represented on tissue microarrays from 25 participating OTTA study sites using a previously validated immunohistochemical (IHC) assay as a surrogate for the presence and functional effect of TP53 mutations. Three abnormal expression patterns (overexpression, complete absence, and cytoplasmic) and the normal (wild type) pattern were recorded. Survival analyses were performed by histotype. The frequency of abnormal p53 expression was 93.4% (4,630/4,957) in HGSC compared to 11.9% (116/973) in EC and 11.5% (86/748) in CCC. In HGSC, there were no differences in overall survival across the abnormal p53 expression patterns. However, in EC and CCC, abnormal p53 expression was associated with an increased risk of death for women diagnosed with EC in multivariate analysis compared to normal p53 as the reference (hazard ratio [HR] = 2.18, 95% confidence interval [CI] 1.36-3.47, p = 0.0011) and with CCC (HR = 1.57, 95% CI 1.11-2.22, p = 0.012). Abnormal p53 was also associated with shorter overall survival in The International Federation of Gynecology and Obstetrics stage I/II EC and CCC. Our study provides further evidence that functional groups of TP53 mutations assessed by abnormal surrogate p53 IHC patterns are not associated with survival in HGSC. In contrast, we validate that abnormal p53 IHC is a strong independent prognostic marker for EC and demonstrate for the first time an independent prognostic association of abnormal p53 IHC with overall survival in patients with CCC.

Molecular characteristics and clinical behaviour of epithelial ovarian cancers

Ovarian carcinoma (OC) is an umbrella term for multiple distinct diseases (histotypes), each with their own developmental origins, clinical behaviour and molecular profile. Accordingly, OC management is progressing away from a one-size-fits all approach, toward more molecularly-driven, histotype-specific management strategies. Our knowledge of driver events in high grade serous OC, the most common histotype, has led to major advances in treatments, including PARP inhibitor use. However, these agents are not suitable for all patients, most notably for many of those with rare OC histotypes. Identification of additional targeted therapeutic strategies will require a detailed understanding of the molecular landscape in each OC histotype. Until recently, tumour profiling studies in rare histotypes were sparse; however, significant advances have been made over the last decade. In particular, reports of genomic characterisation in endometrioid, clear cell, mucinous and low grade serous OC have significantly expanded our understanding of mutational events in these tumour types. Nonetheless, substantial knowledge gaps remain. This review summarises our current understanding of each histotype, highlighting recent advances in these unique diseases and outlining immediate research priorities for accelerating progress toward improving patient outcomes.

Assessing the role of low volume disease in endometrial cancer

The role of retroperitoneal staging in endometrial cancer is still unclear. Although the prognostic value of lymphadenectomy has been demonstrated no data support the therapeutic value of nodal dissection. Sentinel node mapping represents an evolution of lymphadenectomy. Sentinel node mapping allows a more accurate identification of low-volume diseases (i.e., micrometastasis and isolated tumor cells) that are not always detectable via conventional histopathological evaluation. Adjuvant therapy might play a role in patients with low-volume disease. However, the presence of isolated tumor cells alone seems to not impact outcomes of endometrioid endometrial cancer patients. Hence, the choice to deliver adjuvant therapies has to be tailored based on uterine factors only. The introduction of molecular and genomic profiling would be useful in selecting appropriate surgical and adjuvant treatments. The molecular-integrated risk profile should be integrated in clinical practice to overcome the need of retroperitoneal staging (in case of non-bulky nodes) in patients at low risk.