Amy Jamieson

Recurrence rates and patterns of recurrence in stage IA p53abn endometrial cancer with and without myometrial invasion

Optimal management of patients with stage IA p53abn endometrial cancer without myoinvasion, classified as intermediate risk in the 2020 European Society of Gynaecological Oncology, European Society for Radiotherapy and Oncology, and European Society of Pathology (ESGO-ESTRO-ESP) guidelines, and the 2022 European Society of Medical Oncology (ESMO) guidelines, is currently unclear. Practice varies from surgery alone to adjuvant radiation±chemotherapy. Our aim was to assess the risk of disease recurrence in patients with stage IA p53abn endometrial cancer without myoinvasion compared with stage IA with myoinvasion (<50%). Stage IA p53abn endometrial cancers were identified from retrospective cohorts. Cases were segregated into stage IA with no myoinvasion, including (1) tumor restricted to a polyp, (2) residual endometrial tumor, and (3) no residual tumor in hysterectomy specimen, versus stage IA p53abn with myoinvasion (<50%), with treatment and outcomes assessed. There were 65 stage IA p53abn endometrial cancers with no myoinvasion (22 polyp confined, 38 residual endometrial tumor, 2 no residual in hysterectomy specimen, 3 not specified) and 97 with myoinvasion. There was no difference in survival outcomes in patients with stage IA without myoinvasion (16% of patients recurred, 19% if there was residual endometrial disease) compared with stage IA with myoinvasion (17%). The risk of recurrence was lowest in patients with stage IA p53abn endometrial cancer without myoinvasion treated with chemotherapy±radiation (8%). Most recurrences in patients with stage IA without myoinvasion were distant (89%), with no isolated vaginal vault recurrences, and all except one distant recurrence occurred in patients who had not received adjuvant chemotherapy. The recurrence rate in patients with stage IA p53abn endometrial cancer without myoinvasion was 16%, highest in the setting of residual endometrial disease (19%), and exceeding the threshold where adjuvant therapy is often considered. The high frequency of distant recurrences observed may support chemotherapy as part of the treatment regimen.

Targeted and Shallow Whole-Genome Sequencing Identifies Therapeutic Opportunities in p53abn Endometrial Cancers

Abstract Purpose: Shallow whole-genome sequencing (sWGS) can detect copy-number (CN) aberrations. In high-grade serous ovarian cancer (HGSOC) sWGS identified CN signatures such as homologous recombination deficiency (HRD) to direct therapy. We applied sWGS with targeted sequencing to p53abn endometrial cancers to identify additional prognostic stratification and therapeutic opportunities. Experimental Design: sWGS and targeted panel sequencing was performed on formalin-fixed, paraffin-embedded p53abn endometrial cancers. CN alterations, mutational data and CN signatures were derived, and associations to clinicopathologic and outcomes data were assessed. Results: In 187 p53abn endometrial cancers, 5 distinct CN signatures were identified. Signature 5 was associated with BRCA1/2 CN loss with features similar to HGSOC HRD signature. Twenty-two percent of potential HRD cases were identified, 35 patients with signature 5, and 8 patients with BRCA1/2 somatic mutations. Signatures 3 and 4 were associated with a high ploidy state, and CCNE1, ERBB2, and MYC amplifications, with mutations in PIK3CA enriched in signature 3. We observed improved overall survival (OS) for patients with signature 2 and worse OS for signatures 1 and 3. Twenty-eight percent of patients had CCNE1 amplification and this subset was enriched with carcinosarcoma histotype. Thirty-four percent of patients, across all histotypes, had ERBB2 amplification and/or HER2 overexpression on IHC, which was associated with worse outcomes. Mutations in PPP2R1A (29%) and FBXW7 (16%) were among the top 5 most common mutations. Conclusions: sWGS and targeted sequencing identified therapeutic opportunities in 75% of patients with p53abn endometrial cancer. Further research is needed to determine the efficacy of treatments targeting these identified pathways within p53abn endometrial cancers.

Clinical Behavior and Molecular Landscape of Stage I p53-Abnormal Low-Grade Endometrioid Endometrial Carcinomas

Abstract Purpose: The clinical significance of the p53-abnormal (p53abn) molecular subtype in stage I low-grade endometrioid endometrial carcinoma (EEC) is debated. We aimed to review pathologic and molecular characteristics, and outcomes of stage I low-grade p53abn EEC in a large international cohort. Experimental Design: Previously diagnosed stage I p53abn EC (POLE–wild-type, mismatch repair–proficient) low-grade EEC from Canadian retrospective cohorts and PORTEC-1&amp;2 trials were included. Pathology review was performed by six expert gynecologic pathologists blinded to p53 status. IHC profiling, next-generation sequencing, and shallow whole-genome sequencing was performed. Kaplan–Meier method was used for survival analysis. Results: We identified 55 stage I p53abn low-grade EEC among 3,387 cases (2.5%). On pathology review, 17 cases (31%) were not diagnosed as low-grade EEC by any pathologists, whereas 26 cases (47%) were diagnosed as low-grade EEC by at least three pathologists. The IHC and molecular profile of the latter cases were consistent with low-grade EEC morphology (ER/PR positivity, patchy p16 expression, PIK3CA and PTEN mutations) but they also showed features of p53abn EC (TP53 mutations, many copy-number alterations). These cases had a clinically relevant risk of disease recurrence (5-year recurrence-free survival 77%), with pelvic and/or distant recurrences observed in 12% of the patients. Conclusions: A subset of p53abn EC is morphologically low-grade EEC and exhibit genomic instability. Even for stage I disease, p53abn low-grade EEC are at substantial risk of disease recurrence. These findings highlight the clinical relevance of universal p53-testing, even in low-grade EEC, to identify women at increased risk of recurrence.

Co-existent endometrial and ovarian carcinoma: molecular and pathological features define low risk entity

Most co-existent endometrial and ovarian carcinomas are clonally related and exhibit an indolent disease course. Pathologic assignment and clinical management of this entity vary greatly. The International Federation of Gynecology and Obstetrics (FIGO) 2023 endometrial carcinoma staging/risk stratification system introduced a new substage for co-existent endometrial and ovarian carcinomas that meet strict pathologic criteria (stage IA3, distinct from IIIA1). Our aim was to validate if FIGO IA3 identifies a subset of co-existent endometrial and ovarian carcinomas at very low risk of recurrence and determine whether further refinement, through molecular features and expanded ovarian pathologic criteria, could improve prognostic discernment and direct more patients for consideration of de-escalation. Clinicopathologic, molecular, and outcome data were collected on patients with co-existent endometrial and ovarian carcinoma, extracted from pathology archives and molecularly classified endometrial carcinoma cohorts. Among the 154 co-existent endometrial and ovarian carcinoma patients, higher recurrence rates were observed with the p53abn (2/6, 33%), mismatch repair deficiency (MMRd) (7/34, 21%) or no specific molecular profile (NSMP) estrogen receptor (ER) negative-low (2/15, 13%) molecular sub-types, compared with patients with POLEmut or NSMP ER strong positive tumors. Thirty-two patients met FIGO IA3 criteria, with one recurrence and death event (MMRd). Eliminating patients with adverse molecular features (p53abn or MMRd endometrium or ovary, or NSMP ER negative-low endometrium) and expanding criteria to include any POLEmut or cases with bilateral ovarian involvement, intra- or pre-operative ovarian rupture, or ovarian surface involvement significantly improved risk stratification (p = .008) and added 48 co-existent endometrial and ovarian carcinoma patients (>2-fold increase) with no recurrence events (mean follow-up: 6 years). There was 91% concordance of molecular sub-type assignment between endometrial and ovarian tumors. FIGO IA3 criteria identify a subset of co-existent endometrial and ovarian carcinomas with excellent outcomes. However, incorporating molecular features into the definition enables greater prognostic discernment and supports the inclusion of patients with a broader range of pathologic features with indolent disease (increased from 20% to 49% of the cohort, 0 recurrences) who may be candidates for treatment de-escalation.

Papillary and ductal patterns of mesonephric‐like adenocarcinomas are often overlooked: a retrospective revaluation of over 1000 endometrial carcinomas

AimsMesonephric‐like adenocarcinoma (MLA) of the endometrium is often a diagnostic challenge, due to its morphological resemblance to other more common Müllerian neoplasms. This study aimed to retrospectively identify overlooked MLA in a large endometrial carcinoma cohort, using a combination of immunohistochemistry (IHC), morphology and KRAS sequencing.Methods and resultsIHC was conducted on 1094 endometrial carcinomas, identifying 16 potential MLA cases based on GATA3+ and/or TTF1+ and ER− staining patterns, which subsequently underwent detailed histological review, KRAS sequencing and ProMisE molecular classification. Of the IHC screen‐positive cases, one was positive for both GATA3 and TTF1, nine were positive for GATA3 only and six were positive for TTF1 only. All IHC screen‐positive cases were POLE wild‐type. All five tumours in the NSMP category showed morphological features of MLA, while the three MMRd and eight p53abn tumours did not show MLA morphology. The five cases diagnosed as MLA on review were all originally diagnosed as low‐grade endometrioid adenocarcinoma probably because of rare morphological patterns, being predominantly papillary or ductal. Four of the five cases harboured a KRAS mutation.ConclusionThis study highlights the importance of a comprehensive diagnostic approach for accurately identifying endometrial MLA and for pathologists to be aware of papillary and ductal patterns in endometrial carcinoma assessment. Further exploration into the molecular landscape of MLA is essential for refining diagnostic criteria and developing targeted therapies.

Validation and clinical performance of a single test, DNA based endometrial cancer molecular classifier

We have previously shown that DNA based, single test molecular classification by next generation sequencing (NGS) (Proactive Molecular risk classifier for Endometrial cancer (ProMisE) NGS) is highly concordant with the original ProMisE classifier and maintains prognostic value in endometrial cancer. Our aim was to validate ProMisE NGS in an independent cohort and assess the performance of ProMisE NGS in real world clinical practice to address if there were any practical challenges or learning points for implementation. We evaluated DNA extracted from an external research cohort of 211 endometrial cancer cases diagnosed in 2016 from Germany, Switzerland, and Austria, across seven European centers, comparing standard molecular classification (NGS for A total of 545 endometrial cancers were compared. Prognostic differences in progression free, disease specific, and overall survival between the four molecular subtypes were observed for the NGS classifier, recapitulating the survival curves of original ProMisE. In 28 of 545 (5%) discordant cases (8/211 (4%) in the validation set, 20/334 (6%) in the real world cohort), molecular subtype was able to be definitively assigned in all, based on review of the histopathological features and/or additional immunohistochemistry. DNA based molecular classification identified twice as many 'multiple classifier' endometrial cancers; 37 of 545 (7%) compared with 20 of 545 (4%) with original ProMisE. External validation confirmed that single test, DNA based molecular classification was highly concordant (95%) with original ProMisE classification, with prognostic value maintained, representing an acceptable alternative for clinical practice. Careful consideration of reasons for discordance and knowledge of how to correctly assign multiple classifier endometrial cancers is imperative for implementation.

Grade and Estrogen Receptor Expression Identify a Subset of No Specific Molecular Profile Endometrial Carcinomas at a Very Low Risk of Disease-Specific Death

Endometrial carcinoma (EC) can be divided into 4 prognostic molecular subtypes, and no specific molecular profile (NSMP) type is the most commonly occurring type (∼50%). Although described as having an intermediate to favorable prognosis, this subtype encompasses pathologically and molecularly diverse tumors. We aimed to identify factors associated with outcomes within the NSMP ECs that might be used to stratify prognosis and direct treatment. Clinicopathologic, immunohistochemical, and genetic features of a large series of NSMP EC were used to identify parameters that could identify the subset associated with a very favorable outcome (disease-specific death rate 1%], 84% of cases), which showed a 5-year disease-specific death rate of 1.6% across all stages and 1.4% within stage I. The remaining cases (high-risk NSMPs, grade 3, and/or ER-negative status) were responsible for most of the disease-specific deaths (disease-specific death rate at 5 years, 22.9%; hazard ratio compared with that of low-risk NSMPs: 16.3; 95% CI, 8.4-31.7). Within NSMP EC, the low-risk and high-risk categories were of prognostic significance independent of the stage on a multivariate analysis. Low-grade and ER-positive NSMP ECs are a homogeneous low-risk group associated with an exceptionally favorable prognosis in which de-escalation and/or endocrine therapy strategies can be applied. Grade 3 and/or ER-negative status identifies a high-risk NSMP subset, including rare high-grade histotypes (eg, clear cell, dedifferentiated, and mesonephric-like), responsible for most NSMP-related deaths. Subclassification of NSMPs allows for the category of low-risk EC molecular subtypes to be dramatically expanded because it now includes both POLEmut and the much more common low-risk NSMP EC.

Molecular subclassification of vulvar squamous cell carcinoma: reproducibility and prognostic significance of a novel surgical technique

Vulvar squamous cell carcinoma is subclassified into three prognostically relevant groups: (i) human papillomavirus (HPV) associated, (ii) HPV independent p53 abnormal (mutant pattern), and (iii) HPV independent p53 wild type. Immunohistochemistry for p16 and p53 serve as surrogates for HPV viral integration and In this retrospective cohort study, 68 cases treated by vulvar field resection were identified from the Leipzig School of Radical Pelvic Surgery. Immunohistochemistry for p16 and p53 was performed at three different institutions and evaluated independently by seven pathologists and two trainees. Tumors were classified into one of four groups: HPV associated, HPV independent p53 wild type, HPV independent p53 abnormal, and indeterminate. Selected cases were further interrogated by (HPV RNA in situ hybridization, Final subclassification yielded 22 (32.4%) HPV associated, 41 (60.3%) HPV independent p53 abnormal, and 5 (7.3%) HPV independent p53 wild type tumors. Interobserver agreement (overall Fleiss' kappa statistic) for the four category classification was 0.74. No statistically significant differences in clinical outcomes between HPV associated and HPV independent vulvar squamous cell carcinoma were observed. Interobserver reproducibility of vulvar squamous cell carcinoma subclassification based on p16 and p53 immunohistochemistry may support routine use in clinical practice. Vulvar field resection surgery showed no significant difference in clinical outcomes when stratified based on HPV status.

Proteomic analysis uncovers biological diversity in molecularly defined endometrial carcinomas

While endometrial cancer has an overall favorable prognosis, some patients have poor outcomes and may benefit from further refinements of the current classification systems. Molecular classification stratifies endometrial cancer patients into four prognostic subtypes: POLEmut, MMRd (mismatch repair deficient), p53abn, and NSMP (no specific molecular profile), where patients with POLEmut have the best prognosis and p53abn has the worst prognosis. We used proteomic profiling to assess if additional prognostic or predictive information could be identified across or within molecular subtypes. Global proteome profiling of formalin fixed, paraffin embedded samples, that had clinicopathologic and outcome data, was performed on 184 endometrial cancers encompassing all four molecular subtypes, including replicate samples of the same tumor, and both biopsy and final hysterectomy specimens. To ensure representation of each subtype, we profiled an approximately equal distribution in the 148 unique tumors; 34 (23%) POLEmut, 40 (27%) MMRd, 35 (24%) p53abn and 39 (26%) NSMP, rather than the population-based distributions. There was high reproducibility in the proteomic profiles of intra-tumor replicate samples, and between matched biopsy and hysterectomy tumor samples. Consensus clustering identified four clusters with different prognosis, named 'Adhesion', 'Immune', 'Proliferation', and 'Metabolic' based on the functional characteristics of the enriched proteins. We associated protein expression features with common mutations, molecular subtype, and outcomes. These results demonstrate the biologic diversity within endometrial cancers, both between and within molecular subtypes, and provide candidate features for functional and clinical investigation.

Integrating molecular classification into endometrial cancer management

Endometrial carcinoma is biologically heterogeneous. Molecular classification derived from The Cancer Genome Atlas (TCGA) identifies clinically relevant molecular subtypes, each with distinct prognostic and therapeutic implications. FIGO 2023 recognizes tumor biology in staging, and the new 2025 ESGO guidelines incorporate molecular data into risk-stratified management. This is a position paper on the incorporation of molecular classification in endometrial cancer. We focused on molecular taxonomy, diagnostic surrogates, prognostic validation, and therapeutic implications of immune and targeted agents. The five molecular subtypes (POLEmut; MMRd/MSI-H; p53abn; NSMP ER-positive; NSMP ER-negative) provide stronger prognostic discrimination than grade or histotype alone. We recommend that molecular subtype should guide adjuvant treatment de-escalation or intensification, inform the use of immunotherapy and targeted agents, and refine risk stratification beyond conventional parameters. We also discussed implementation challenges, including test standardization, reporting, equity of access, and areas of ongoing uncertainty. This position paper aims to support consistent, equitable, and biologically informed management of endometrial carcinoma in contemporary practice.