Naveena Singh

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&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.

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.

The spectrum of oestrogen receptor expression in endometrial carcinomas of no specific molecular profile

AimsDecreased oestrogen receptor (ER) expression is a marker of poor prognosis in endometrial carcinomas (EC) of no specific molecular profile (NSMP), but the optimal cut‐off to separate high‐risk ‘low ER’ versus low‐risk ‘high ER’ expression has not been defined. Here we characterised the distribution of ER staining in a cohort of ECs.Methods and resultsBiopsy specimens from 120 cases of NSMP EC were stained for ER and assigned an Allred score. In 66 additional cases ER staining of matched biopsy and hysterectomy were compared. Twelve of 120 tumours had an Allred score of 0–3, including three endometrioid carcinomas (EEA) (one G1, two G3), four clear cell carcinomas (CCC), two mesonephric‐like adenocarcinoma (MLA) and one each of: gastric‐type adenocarcinoma, carcinosarcoma and endometrial carcinoma NOS. Three had Allred scores of 4–5: two MLA and one high‐grade carcinoma with yolk sac differentiation. Five had Allred scores of 6: four EEA (one G1, one G2, two G3) and one mixed clear cell and endometrioid carcinoma. The remaining 100 tumours with Allred scores ≥ 7 were all EEA (66 G1, 28 G2, five G3 and one grade unknown). Comparing the biopsy versus hysterectomy ER staining (n = 66), the results were within a single Allred score point, except two cases with strong diffuse expression in the biopsy (Allred 8) and moderate expression in the hysterectomy (Allred 5).ConclusionsMost NSMP ECs (> 80%) show high ER expression (Allred score ≥ 7). All non‐endometrioid carcinomas and a few endometrioid carcinomas had lower ER expression (Allred score ≤ 6) or were completely negative.

Performance of a HER2 testing algorithm specific for p53‐abnormal endometrial cancer

AimsHuman epidermal growth factor receptor 2 (HER2) amplification in endometrial cancer (EC) is almost completely confined to the p53‐abnormal (p53abn) molecular subtype and independent of histological subtype. HER2 testing should therefore be molecular subtype‐directed. However, the most optimal approach for HER2 testing in EC has not been fully established. Therefore, we developed an EC‐specific HER2 immunohistochemistry (IHC) scoring method and evaluated its reproducibility and performance to establish an optimal diagnostic HER2 testing algorithm for p53abn EC.Methods and resultsHER2 IHC slides of 78 p53abn EC were scored by six gynaecopathologists according to predefined EC‐specific IHC scoring criteria. Interobserver agreement was calculated using Fleiss’ kappa and the first‐order agreement coefficient (AC1). The consensus IHC score was compared with HER2 dual in‐situ hybridisation (DISH) results. Sensitivity and specificity were calculated. A substantial interobserver agreement was found using three‐ or two‐tiered scoring [κ = 0.675, 95% confidence interval (CI) = 0.633–0.717; AC1 = 0.723, 95% CI = 0.643–0.804 and κ = 0.771, 95% CI = 0.714–0.828; AC1 = 0.774, 95% CI = 0.684–0.865, respectively]. Sensitivity and specificity for the identification of HER2‐positive EC was 100 and 97%, respectively, using a HER2 testing algorithm that recommends DISH in all cases with moderate membranous staining in >10% of the tumour (IHC+). Performing DISH on all IHC‐2+ and ‐3+ cases yields a sensitivity and specificity of 100%.ConclusionsOur EC‐specific HER2 IHC scoring method is reproducible. A screening strategy based on IHC scoring on all cases with subsequent DISH testing on IHC‐2+/‐3+ cases has perfect test accuracy for identifying HER2‐positive EC.

Metastases to the ovary arising from endometrial, cervical and fallopian tube cancer: recent advances

The introduction of genomic studies has enabled assessment of the clonality of synchronous tumours involving the ovary and other sites in the female genital tract in a definitive way. This has led to the abandonment of conventional approaches to primary site assignment, and the recognition that most such synchronous neoplasms are clonally related single tumours with metastatic spread, rather than independent primary tumours. These discoveries have implications for diagnostic practice, analogous to the gradual change over the last few decades in our approach to mucinous neoplasms of the ovary metastatic from the gastrointestinal tract. In this review, we first examine the routes of metastasis to the ovary, and then discuss the diagnostic and clinical implications of concurrent ovarian carcinomas arising in combination with endometrial, endocervical and tubal carcinomas. It is proposed that cases of primary low‐grade endometrioid endometrial carcinoma with a secondary unilateral ovarian tumour, both with indolent characteristics, may be classified as ‘FIGO stage IIIA‐simulating independent primary tumours’, with a comment that conservative management would be appropriate. It should be recognised that human papillomavirus‐associated endocervical adenocarcinomas may result in synchronous or metachronous ovarian metastases that appear to be unrelated to the primary tumour, and that these may be managed conservatively in the absence of other sites of disease. In cases of tubo‐ovarian high‐grade serous carcinoma, tubal intraepithelial or contralateral adnexal involvement should count as a pelvic disease site for staging purposes.

p53 immunohistochemistry is an accurate surrogate for TP53 mutational analysis in endometrial carcinoma biopsies

AbstractTP53 mutations are considered a surrogate biomarker of the serous‐like ‘copy number high’ molecular subtype of endometrial carcinoma (EC). In ovarian carcinoma, p53 immunohistochemistry (IHC) accurately reflects mutational status with almost 100% specificity but its performance in EC has not been established. This study tested whether p53 IHC reliably predicts TP53 mutations identified by next‐generation sequencing (NGS) in EC biopsy samples for all ECs and as part of a molecular classification algorithm after exclusion of cases harbouring mismatch repair defects (MMRd) or pathogenic DNA polymerase epsilon exonuclease domain mutations (POLEmut). A secondary aim assessed inter‐laboratory variability in p53 IHC. From a total of 207 cases from five centres (37–49 cases per centre), p53 IHC carried out at a central reference laboratory was compared with local IHC (n = 164) and curated tagged‐amplicon NGS TP53 sequencing results (n = 177). Following consensus review, local and central p53 IHC results were concordant in 156/164 (95.1%) tumours. Discordant results were attributable to both interpretive and technical differences in staining between the local and central laboratories. When results were considered as any mutant pattern versus wild‐type pattern staining, however, there was disagreement between local and central review in only one case. The concordance between p53 IHC and TP53 mutation was 155/168 (92.3%) overall, and 117/123 (95.1%) after excluding MMRd and POLEmut EC. Three (3/6) discordant results were in serous carcinomas with complete absence of p53 staining but no detectable TP53 mutation. Subclonal mutant p53 IHC expression was observed in 9/177 (5.1%) cases, of which four were either MMRd or POLEmut. Mutant pattern p53 IHC was observed in 63/63 (100%) serous carcinomas that were MMR‐proficient/POLE exonuclease domain wild‐type. Optimised p53 IHC performs well as a surrogate test for TP53 mutation in EC biopsies, demonstrates excellent inter‐laboratory reproducibility, and has high clinical utility for molecular classification algorithms in EC. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

The avoiding late diagnosis of ovarian cancer (ALDO) project; a pilot national surveillance programme for women with pathogenic germline variants inBRCA1andBRCA2

BackgroundOur study aimed to establish ‘real-world’ performance and cost-effectiveness of ovarian cancer (OC) surveillance in women with pathogenic germlineBRCA1/2variants who defer risk-reducing bilateral salpingo-oophorectomy (RRSO).MethodsOur study recruited 875 femaleBRCA1/2-heterozygotes at 13 UK centres and via an online media campaign, with 767 undergoing at least one 4-monthly surveillance test with the Risk of Ovarian Cancer Algorithm (ROCA) test. Surveillance performance was calculated with modelling of occult cancers detected at RRSO. The incremental cost-effectiveness ratio (ICER) was calculated using Markov population cohort simulation.ResultsOur study identified 8 OCs during 1277 women screen years: 2 occult OCs at RRSO (both stage 1a), and 6 screen-detected; 3 of 6 (50%) were ≤stage 3a and 5 of 6 (83%) were completely surgically cytoreduced. Modelled sensitivity, specificity, Positive Predictive Value (PPV) and Negative Predictive Value (NPV) for OC were 87.5% (95% CI, 47.3 to 99.7), 99.9% (99.9–100), 75% (34.9–96.8) and 99.9% (99.9–100), respectively. The predicted number of quality-adjusted life years (QALY) gained by surveillance was 0.179 with an ICER cost-saving of -£102,496/QALY.ConclusionOC surveillance for women deferring RRSO in a ‘real-world’ setting is feasible and demonstrates similar performance to research trials; it down-stages OC, leading to a high complete cytoreduction rate and is cost-saving in the UK National Health Service (NHS) setting. While RRSO remains recommended management, ROCA-based surveillance may be considered for femaleBRCA-heterozygotes who are deferring such surgery.

Vulval squamous cell carcinoma and its precursors

Vulval squamous cell carcinoma (VSCC) can arise through two distinct pathways [human papillomavirus (HPV)‐associated and HPV‐independent], and these VSCC variants are recognised as different disease entities on the basis of different aetiologies, morphological features, molecular events during oncogenesis, precursor lesions, prognosis, and response to treatment. The precursor of HPV‐associated VSCC, variously referred to as high‐grade squamous intraepithelial lesion (HSIL) [vulvar intraepithelial neoplasia (VIN) 2/3] or usual‐type VIN, is morphologically identical to the more common HSIL (cervical intraepithelial neoplasia 2/3) of the cervix. The precursor lesions of HPV‐independent VSCC include differentiated VIN, differentiated exophytic vulvar intraepithelial lesion, and vulvar acanthosis with altered differentiation; these have been under‐recognised by pathologists in the past, leading to delays in treatment. This review will discuss the recent advances in diagnostic surgical pathology of VSCC and its precursors, and how these diagnoses can impact on patient management.