Molecular Characterization of Endometrial Carcinomas in Black and White Patients Reveals Disparate Drivers with Therapeutic Implications

Histologic and Molecular Type Changes in Endometrial Cancer Recurrences in Comparison With Their Corresponding Primary Tumors

In this study, molecular alterations in endometrial carcinoma (EC) recurrences were analyzed. We aimed to identify genes implicated in tumor progression and to evaluate whether histologic and molecular type shifting occurs in recurrences. Thus, we analyzed 50 samples corresponding to 24 primary ECs (15 low-grade endometrioid endometrial carcinomas [LG-EECs] and 9 high-grade endometrial carcinomas) and their corresponding 26 recurrences. These were studied by immunohistochemistry, next-generation sequencing, and MLH1 promoter methylation. We observed shared mutations in all primary tumors and their recurrences, indicating a clonal relationship between both lesions. Most morphologic and molecular changes associated with progression were found in LG-EEC. In this group, 6 patients (40%) presented additional mutations in the recurrence. These mutations more frequently affected genes of the PI3K/AKT/PTEN pathway, implicating this pathway not only in tumor initiation but also in progression. In addition, 2 patients (13%) in which the primary tumor belonged to the nonspecific molecular profile subtype, shifted to the mismatch repair deficient (MMRd) subtype after the acquisition of MLH1 promoter methylation in the recurrence lesions. In 3 patients (20%) with MMRd, there was a change from LG-EEC to G3-EEC. One TP53-mutated LG-EEC transformed into an undifferentiated carcinoma in a mediastinal lymph node metastasis after losing the expression of SMARCA2 while preserving SMARCA4 and SMARCB1. Morphologic and molecular changes in EC recurrences, especially dedifferentiation and the acquisition of MMRd, should be considered for a correct diagnosis and treatment. MMRd should be tested in metastatic lesions, if available, in patients with primary tumors reported to be of a molecular subtype different from MMRd.

Single-cell RNA sequencing in endometrial cancer: exploring the epithelial cells and the microenvironment landscape

Single-cell RNA sequencing (scRNA-seq) technology has emerged as a powerful tool for dissecting cellular heterogeneity and understanding the intricate biology of diseases, including cancer. Endometrial cancer (EC) stands out as the most prevalent gynecological malignancy in Europe and the second most diagnosed worldwide, yet its cellular complexity remains poorly understood. In this review, we explore the contributions of scRNA-seq studies to shed light on the tumor cells and cellular landscape of EC. We discuss the diverse tumoral and microenvironmental populations identified through scRNA-seq, highlighting the implications for understanding disease progression. Furthermore, we address potential limitations inherent in scRNA-seq studies, such as technical biases and sample size constraints, emphasizing the need for larger-scale research encompassing a broader spectrum of EC histological subtypes. Notably, a significant proportion of scRNA-seq analyses have focused on primary endometrioid carcinoma tumors, underscoring the need to incorporate additional histological and aggressive types to comprehensively capture the heterogeneity of EC. By critically evaluating the current state of scRNA-seq research in EC, this review underscores the importance of advancing towards more comprehensive studies to accelerate our understanding of this complex disease.

Immunohistochemical p16 overexpression and Rb loss correlate with high-risk human papillomavirus infection in endocervical adenocarcinomas

AIMS

p16 is a sensitive surrogate marker for transcriptionally active high-risk human papillomavirus (HR-HPV) infection in endocervical adenocarcinoma (ECA); however, its specificity is not perfect.

METHODS AND RESULTS

We examined p16 and Rb expressions by immunohistochemistry (IHC) and the transcriptionally active HR-HPV infection by mRNA in-situ hybridisation (ISH) with histological review in 108 ECA cases. Thirteen adenocarcinomas of endometrial or equivocal origin (six endometrioid and seven serous carcinomas) were compared as the control group. HR-HPV was detected in 83 of 108 ECA cases (77%), including five HPV-associated adenocarcinomas in situ and 78 invasive HPV-associated adenocarcinomas. All 83 HPV-positive cases showed consistent morphology, p16 positivity and partial loss pattern of Rb. Among the 25 cases of HPV-independent adenocarcinoma, four (16%) were positive for p16, and of these four cases, three of 14 (21%) were gastric type adenocarcinomas and one of 10 (10%) was a clear cell type adenocarcinoma. All 25 HPV-independent adenocarcinomas showed preserved expression of Rb irrespective of the p16 status. Similarly, all 13 cases of the control group were negative for HR-HPV with preserved expression of Rb, even though six of 13 (46%) cases were positive for p16. Compared with p16 alone, the combination of p16 overexpression and Rb partial loss pattern showed equally excellent sensitivity (each 100%) and improved specificity (100 versus 73.6%) and positive predictive values (100 versus 89.2%) in the ECA and control groups. Furthermore, HR-HPV infection correlated with better prognosis among invasive ECAs.

CONCLUSIONS

The results suggest that the combined use of p16 and Rb IHC could be a reliable method to predict HR-HPV infection in primary ECAs and mimics. This finding may contribute to prognostic prediction and therapeutic strategy.

APOBEC3 mutagenesis drives therapy resistance in breast cancer

Acquired genetic alterations commonly drive resistance to endocrine and targeted therapies in metastatic breast cancer 1-7 , however the underlying processes engendering these diverse alterations are largely uncharacterized. To identify the mutational processes operant in breast cancer and their impact on clinical outcomes, we utilized a well-annotated cohort of 3,880 patient samples with paired tumor-normal sequencing data. The mutational signatures associated with apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like 3 (APOBEC3) enzymes were highly prevalent and enriched in post-treatment compared to treatment-naïve hormone receptor-positive (HR+) cancers. APOBEC3 mutational signatures were independently associated with shorter progression-free survival on antiestrogen plus CDK4/6 inhibitor combination therapy in patients with HR+ metastatic breast cancer. Whole genome sequencing (WGS) of breast cancer models and selected paired primary-metastatic samples demonstrated that active APOBEC3 mutagenesis promoted resistance to both endocrine and targeted therapies through characteristic alterations such as RB1 loss-of-function mutations. Evidence of APOBEC3 activity in pre-treatment samples illustrated a pervasive role for this mutational process in breast cancer evolution. The study reveals APOBEC3 mutagenesis to be a frequent mediator of therapy resistance in breast cancer and highlights its potential as a biomarker and target for overcoming resistance.

Novel Molecular Targets in Endometrial Cancer: Mechanisms and Perspectives for Therapy

Endometrial cancer (EC) has a high epidemiological impact with incidence and mortality rising worldwide. In recent years, the integration of the pathologic and molecular classification has provided relevant information to understand the heterogeneity in the biology of EC, which led to the evolution in the management of patients. Currently, therapeutic breakthroughs have been made in advanced EC to improve oncologic outcomes, with efforts to include patient reported outcomes. Precision and personalized medicine are under way in EC exploring different combination approaches to target cross-talk pathways, cancer cell microenvironment, and metabolic vulnerabilities and improve drug delivery. Yet, collaborative efforts are needed to face the challenges in practice by refining patient selection, ideal biomarker identification, and de-escalation of therapies according to emerging molecular and genomic features of EC.

Racioethnic Disparities in Endometrial Cancer Outcomes

Black women are twice as likely to die from endometrial cancer (EC) compared with white women. This represents one of the worst racioethnic disparities amongst all cancers globally. Compared with white women, black women are more likely to be diagnosed with advanced EC, have more barriers to accessing care and experience increased delays in obtaining an EC diagnosis and commencing treatment. Histological and molecular differences place black women at higher risk of being diagnosed with more aggressive EC subtypes that carry less favourable outcomes. Furthermore, EC diagnostic pathways are less reliable in black women, and black women are less likely to receive evidence-based treatment for EC. This racioethnic disparity in EC outcomes exists both in the UK and US, despite differences in healthcare systems. This review methodically describes the key factors along the patient journey that contribute to the disparity in black women and proposes multifaceted approaches to lessen these gaps.

Moving into the modern era of molecular classification for endometrial cancer

The molecular subtypes of endometrial carcinoma (EC) were first described by The Cancer Genome Atlas (TCGA) a decade ago. Using surrogate approaches, the molecular classification has been demonstrated to be prognostic across EC patients and to have predictive implications. Starting in 2020, the molecular classification has been incorporated into multiple guidelines as part of the risk assessment and most recently into the International Federation of Gynecology and Obstetrics (FIGO) staging. This review article discusses the implementation of the EC molecular classification into clinical practice, the therapeutic implications, and the molecular and clinical heterogeneity of the EC molecular subtypes.

Computational Image and Molecular Analysis Reveal Unique Prognostic Features of Immune Architecture in African Versus European American Women with Endometrial Cancer

Endometrial cancer (EC) disproportionately affects African American (AA) women in terms of progression and death. In our study, we sought to employ computerized image and bioinformatic analysis to tease out morphologic and molecular differences in EC between AA and European-American (EA) populations. We identified the differences in immune cell spatial patterns between AA and EA populations with markers of tumor biology, including histologic and molecular subtypes. The models performed best when they were trained and validated using data from the same population. Unsupervised clustering revealed a distinct association between immune cell features and known molecular subtypes of endometrial cancer that varied between AA and EA populations. Our genomic analysis revealed two distinct and novel gene sets with mutations associated with improved prognosis in AA and EA patients. Our study findings suggest the need for population-specific risk prediction models for women with endometrial cancer.