A comparison of p53 and WT1 immunohistochemical expression patterns in tubo-ovarian high-grade serous carcinoma before and after neoadjuvant chemotherapy

Cytohistologic immunohistochemical correlation of epithelial tubo-ovarian neoplasms: Can cell blocks substitute for tissue?

BACKGROUND

Cytologic specimens often represent the initial diagnostic material for tubo-ovarian neoplasms resulting from therapeutic paracentesis for patients presenting with high-volume ascites. However, subtyping and immunohistochemical (IHC) characterization, which have implications in preoperative management and downstream ancillary testing, are not routinely performed in many institutions. This study aims to perform cytohistologic correlation of commonly used IHC stains to establish their reliability in peritoneal fluids/washing specimens.

METHODS

A retrospective search of the laboratory information systems was performed to identify peritoneal fluid/washing specimens involved by borderline or malignant epithelial tubo-ovarian neoplasms and concurrent/subsequent surgical resection specimens. Cell blocks and tissue were stained for PAX8, WT-1, p53, p16, Napsin-A, estrogen receptor, and progesterone receptor, and staining between cytological and surgical specimens was compared.

RESULTS

A total of 56 case pairs were included, with the following final diagnoses on histological examination: 37 high-grade serous carcinomas, eight clear cell carcinomas, one endometrioid adenocarcinoma, two low-grade serous carcinomas, and eight serous borderline tumors. There was perfect cytohistologic correlation for PAX8 (Lin's concordance correlation coefficient [LINCCC] = 1.00) and WT-1 (LINCCC = 1.00), substantial/good correlation for p53 (LINCCC = 0.96), p16 (LINCCC = 0.93), napsin-A (LINCCC = 0.91) and ER (LINCCC = 0.77), and moderate correlation for PR (LINCCC = 0.54).

CONCLUSIONS

Immunohistochemical correlation between peritoneal fluid and surgical resection specimens for tubo-ovarian neoplasms is high. Common subtypes of tubo-ovarian carcinomas can be reliably distinguished on fluids using IHC.

Clinical outcomes of immunohistochemistry of the p53 Staining pattern in high-grade serous ovarian carcinoma

Objective

To investigate the prevalence of p53 mutations and associated factors between immunohistochemistry (IHC) and p53 staining patterns among patients with high-grade serous ovarian carcinoma (HGSOC).

Methods

This study is a retrospective review. A total of 62 patients with HGSOC underwent surgery at Srinagarind Hospital between January 2016 and December 2020. Histological examination was performed based on a combination of morphology and IHC staining with p53. The p53 immunostaining pattern was interpreted as a missense mutation, nonsense mutation, or a wild-type pattern. Missense (p53 overexpression pattern) and nonsense (null expression p53 pattern) mutations were considered p53 mutations. A wild-type pattern was defined as a p53 non-mutation.

Results

p53 mutations were identified in 93.6% of the patients. Subgroup analysis of the p53 mutation group between the p53 overexpression pattern and the p53 null expression pattern in terms of clinicopathological characteristics and initial treatment was performed. Patients with the p53 overexpression pattern had significantly more omental metastases than those with the p53 null expression pattern (87.8% vs. 64.7%, P=0.042). There were no statistically significant differences in median progression-free survival (PFS) (9 vs. 10 months, P=0.813) or median overall survival (OS) (12 vs. 17 months, P=0.526) between the two groups.

Conclusion

The prevalence of p53 mutations in HGSOC patients in this study was 93.6%. Omental metastasis is a significant pathological factor in predicting overexpression p53 pattern in HGSC. However, IHC analysis of the p53 staining pattern did not affect OS or PFS among patients with HGSOC.

MCM3 is a novel proliferation marker associated with longer survival for patients with tubo-ovarian high-grade serous carcinoma

Tubo-ovarian high-grade serous carcinomas (HGSC) are highly proliferative neoplasms that generally respond well to platinum/taxane chemotherapy. We recently identified minichromosome maintenance complex component 3 (MCM3), which is involved in the initiation of DNA replication and proliferation, as a favorable prognostic marker in HGSC. Our objective was to further validate whether MCM3 mRNA expression and possibly MCM3 protein levels are associated with survival in patients with HGSC. MCM3 mRNA expression was measured using NanoString expression profiling on formalin-fixed and paraffin-embedded tissue (N = 2355 HGSC) and MCM3 protein expression was assessed by immunohistochemistry (N = 522 HGSC) and compared with Ki-67. Kaplan-Meier curves and the Cox proportional hazards model were used to estimate associations with survival. Among chemotherapy-naïve HGSC, higher MCM3 mRNA expression (one standard deviation increase in the score) was associated with longer overall survival (HR = 0.87, 95% CI 0.81-0.92, p < 0.0001, N = 1840) in multivariable analysis. MCM3 mRNA expression was highest in the HGSC C5.PRO molecular subtype, although no interaction was observed between MCM3, survival and molecular subtypes. MCM3 and Ki-67 protein levels were significantly lower after exposure to neoadjuvant chemotherapy compared to chemotherapy-naïve tumors: 37.0% versus 46.4% and 22.9% versus 34.2%, respectively. Among chemotherapy-naïve HGSC, high MCM3 protein levels were also associated with significantly longer disease-specific survival (HR = 0.52, 95% CI 0.36-0.74, p = 0.0003, N = 392) compared to cases with low MCM3 protein levels in multivariable analysis. MCM3 immunohistochemistry is a promising surrogate marker of proliferation in HGSC.

Evaluation of the incidence and clinical significance of WT-1 expression in uterine serous carcinoma

Background

Wilms tumor gene 1 (WT1) expression is a hallmark of ovarian serous carcinoma and considered to be diagnostic marker of these tumors, differentiating them from uterine serous carcinoma (USC), historically thought to rarely express WT1. However, more recent data indicates a significant percentage of USC may express WT1. The clinical implications of WT1 positivity in USC remain unclear.

Methods

A multicenter retrospective analysis of patients with USC was conducted from 2000 to 2019. Inclusion criteria were patients who had undergone comprehensive surgical staging/tumor debulking with archival tissue available for WT1 assessment via immunohistochemistry (IHC). Chemosensitive patients were defined as those recurring >6 months from last platinum-based chemotherapy. Progression free survival (PFS) and overall survival (OS) analysis was performed using Kaplan-Meier estimates. Multivariate analysis (MVA) was performed using Cox proportional hazards model.

Results

WT1 status was evaluated in 61 patients with USC. 13 (21.3%) were positive for WT1 by IHC. Stage distribution included 32% stage I, 5% stage II, 25% stage III and 38% stage IV. There was no difference in the stage (p = 0.158), race (p = 0.227) or distribution of recurrence sites (p = 0.581) between WT1 positive and WT1 negative tumors. The majority of patients were chemosensitive (63%). Chemosensitivity was significantly improved in WT1 positive (92.3%) vs. WT1 negative tumors (55.8%) (p = 0.016). We observed a trend towards improved PFS among WT1 positive tumors (21 vs. 16-months, respectively) (p = 0.544). On MVA, stage (p < 0.001) and chemosensitivity (p < 0.001) were independent predictors of PFS.

Conclusions

WT1 positivity is observed in over 20% of USC. WT1 expression is associated with improved chemosensitivity which may contribute to improvements in PFS.

Cytoplasmic P53 Immunostaining With N-Terminus P53 Antibody And Absence Of Staining With C-Terminus P53 Antibody: A Report Of Two Pediatric Sarcomas With Distal Truncating TP53 Mutations Affecting Nuclear Localization Domain

P53 immunohistochemical staining with antibodies targeted to epitopes at or near the N-terminus are commonly used in diagnostic pathology practice as a surrogate for TP53 mutations. The abnormal staining patterns indicating TP53 mutations include nuclear overexpression, null, and the recently described cytoplasmic staining. The latter staining pattern occurs with the less common TP53 mutations affecting its nuclear localization and/or tetramerization domains that are located toward the C-terminus. Here we describe the first two cases of pediatric sarcomas with cytoplasmic staining with P53 antibody against N-terminus epitope and the absence of staining with P53 antibody against C-terminus epitope. We propose that a more precise description of P53 immunohistochemical staining patterns should include the nature of the antibody used.

Cytoplasmic Pattern p53 Immunoexpression in Pelvic and Endometrial Carcinomas With TP53 Mutation Involving Nuclear Localization Domains: An Uncommon But Potential Diagnostic Pitfall With Clinical Implications

A cytoplasmic pattern of p53 immunohistochemical expression has recently been reported in a rare subset of pelvic and endometrial cancers with a TP53 mutation involving domains affecting nuclear localization. This study reports the clinicopathologic features of 31 cases with a TP53 mutation involving nuclear localization, the largest study to date, emphasizing practical strategies for recognizing this uncommon variant and distinguishing it from the p53 wild-type pattern. The study also evaluates the prognostic significance of TP53 mutation involving nuclear localization in the ovarian high-grade serous carcinoma (HGSC) cohort of The Cancer Genome Atlas database. Most of the 31 tumors were advanced stage pelvic or endometrial HGSC. All TP53 mutations were predicted to result in loss of function. The p53 overexpression pattern was present in 6 tumors; the p53 null pattern in 3 and the p53 cytoplasmic pattern in 22 tumors. The p53 cytoplasmic pattern predominantly consisted of weak to moderate cytoplasmic staining in >95% of tumor cells as well as variable intensity nuclear staining involving a range of just a few cells to just under 80% of tumor cells. The p53 cytoplasmic pattern was observed in 100% of tumors with TP53 mutation in the nuclear localization domain and in 33% to 44% of tumors with a mutation in the adjacent tetramerization domain or nuclear exclusion sequence (P<0.01). p16 immunoexpression was present in 74% of tumors. In The Cancer Genome Atlas ovarian HGSC cohort, 9% of 471 nonredundant TP53-mutant cases had a nuclear localization domain, tetramerization domain, or nuclear exclusion sequence mutation but there was no significant difference in survival when compared to cases with TP53 mutation outside those domains (P>0.05). p53 cytoplasmic staining merits classification as an aberrant result despite coexisting nuclear staining that in some cases may resemble the p53 wild-type pattern. While positive p16 immunostaining may be of value to confirm diagnostically challenging cases of p53 cytoplasmic staining, a negative result is noninformative and molecular testing for TP53 mutation should be considered, if available.

Morphologic and Immunocytochemical Features of High-Grade Serous Carcinoma of Ovary in Ascitic Fluid Effusion and Fine-Needle Aspiration Cytology

OBJECTIVES

High-grade serous carcinoma (HGSC) is the most common ovarian malignancy. The role of cytopathology in obtaining tissue diagnosis before institution of neoadjuvant chemotherapy (NACT) was evaluated.

METHODS

All histopathology-proven HGSC specimens between 2015 and 2018 with prior cytopathologic diagnosis by ascitic fluid evaluation or fine-needle aspiration (FNA) of ovarian mass were reviewed with cell block immunocytochemistry for CK7, CK20, PAX8, WT1, and p53.

RESULTS

Of 288 cases of HGSC, pre-NACT cytology diagnosis was established in 32% (93/288), with specific HGSC diagnoses made on ascitic fluid in 88% (82/93) and by ovarian mass FNA in 12% (11/93). The ascitic fluid showed moderate/high cellularity with papillary clusters in 76% (71/93) cases. Cell block immunocytochemistry showed tumor cells positive for CK7, PAX8, and WT1. p53 showed mutant or null-type positivity in 65% (33/51) and 33% (17/51) of cases, respectively, with 100% concordance with subsequent histopathology specimens. Poor/intermediate response to chemotherapy was shown in 75% of cases.

CONCLUSIONS

Combined assessment of cytomorphology, cell block histomorphology, and ancillary immunohistochemical testing, including PAX8, WT1, and p53, allows for specific pre-NACT diagnoses of HGSC in ascitic fluid and ovarian FNA cytology. This practice allows for initiation of chemotherapy and diminution of disease burden prior to definitive surgical therapy.

Effect of neoadjuvant chemoradiotherapy on p53 and SOX2 protein expression in esophageal adenocarcinoma

Aim: To determine if neoadjuvant chemoradiotherapy (nCRT) affects p53 and SOX2 expression in esophageal adenocarcinoma (EAC). Materials & methods: Comparison of p53 and SOX2 expression in 100 paired pre- and post-nCRT EAC samples. Results: Aberrant p53 was largely concordant (75/83, 90%), while 13/18 (72%) pre-nCRT samples with wild-type (WT) p53 staining, showed aberrant staining in paired post-nCRT samples. Similarly, 31/45 (69%) with previous WT SOX2 showed SOX2 loss in paired post-nCRT samples, whereas aberrant SOX2 loss was concordant in 50/55 (91%) cases. The prognostic values of both markers regarding survival differ before and after nCRT. Conclusion: Aberrant expression of p53 and SOX2 staining in EAC tissue is unaffected by nCRT. Conversely, the WT-staining pattern frequently changed to aberrant expression.

Apparent Diffusion Coefficient Histogram Analysis for Assessing Tumor Staging and Detection of Lymph Node Metastasis in Epithelial Ovarian Cancer: Correlation with p53 and Ki-67 Expression

PURPOSE

To investigate the potential of apparent diffusion coefficient (ADC) histogram parameters in epithelial ovarian cancer (EOC) for distinguishing different tumor stages and determining lymph node status and correlations between ADC values and p53 and Ki-67 expression.

PROCEDURES

Forty-nine EOC patients underwent preoperative magnetic resonance imaging. Staging and lymph node status were determined postoperatively. ADC values were measured using histogram analysis and compared between groups. Relationships between ADCs and Ki-67 and p53 expression were explored.

RESULTS

DC parameters differed significantly between stage I vs II, I vs III, and I vs IV. The parameters were significantly lower in the lymph node-positive group than in the lymph node-negative group, were significantly negatively correlated with Ki-67 labeling index, and were all significantly lower in the mutation-type p53 group than in the wild-type p53 group.

CONCLUSIONS

ADC histogram analysis can help discriminate stage I from advanced-stage EOC and predict lymph node metastasis. ADC parameters were correlated with Ki-67 labeling index; the parameters may help indicate p53 expression.

Targeted Sequencing of Tubo-ovarian and Peritoneal High-grade Serous Carcinoma With Wild-type p53 Immunostaining Pattern

BACKGROUND/AIM

We aimed to demonstrate the use of next-generation sequencing (NGS) to confirm the presence of tumor protein 53 (TP53) mutations in tubo-ovarian and peritoneal high-grade serous carcinoma (HGSC) with a wild-type p53 immunostaining pattern and investigate whether the TP53 mutational status is altered by chemotherapy.

MATERIALS AND METHODS

A commercial NGS panel comprising 171 genes was used to analyze the genetic profiles of 15 HGSC samples. Paired specimens obtained before and after chemotherapy were available for four patients.

RESULTS

All examined samples exhibited TP53 mutations. For all the patients who underwent neoadjuvant or postoperative adjuvant chemotherapy, TP53 mutations identified in samples obtained after chemotherapy were the same as those detected in pre-chemotherapeutic samples.

CONCLUSION

HGSCs exhibit TP53 mutations even though a subset of HGSCs displayed a wild-type p53 immunostaining pattern. Chemotherapy does not affect the TP53 mutational status in HGSC.

A detailed morphological and immunohistochemical comparison of primary endometrial and tubo-ovarian high-grade serous carcinomas and their corresponding omental metastases

Increasingly, high-grade serous carcinomas (HGSCs) of fallopian tube/ovarian origin are managed initially with neoadjuvant chemotherapy (NACT) and pre-treatment diagnosis is often based upon relatively limited core biopsy and/or cytology specimens. Endometrial HGSC can also present with adnexal and peritoneal metastasis, thus mimicking a primary tubo-ovarian neoplasm, but the role of NACT in these cases is less established. Immunohistochemistry has been considered useful in this distinction but with a wide range of reported findings in the literature. In this study we have examined tumour growth patterns and the expression p16, Ki-67, WT1, PAX2, HER2, ER-α, ER-β, PR, and BAF250a in 18 tubo-ovarian and 14 endometrial HGSCs, comparing the findings in primary and omental sites. Metastatic tubo-ovarian carcinomas demonstrated significantly more varied architectural patterns than metastatic endometrial HGSCs (median 2.5 versus 1). None of the immunohistochemical markers proved completely reliable but only endometrial HGSC were WT1 negative (7/14 metastatic tumours) or demonstrated over-expression of HER2 (2/14 cases). Micropapillary tumour elements more often showed retained PAX2 and WT1 expression, low Ki-67 labelling, and (in endometrial tumours) PR staining. Diverse architectural patterns suggest tubo-ovarian origin in a metastatic HGSC. Immunohistochemical results should be cautiously interpreted, particularly in small specimens.

Ovarian High-Grade Serous Carcinoma: Assessing Pathology for Site of Origin, Staging and Post-neoadjuvant Chemotherapy Changes

High-grade serous (HGSC) stands apart from the other ovarian cancer histotypes in being the most frequent, in occurring as part of a genetic predisposition in a significant proportion of cases, and in having the poorest clinical outcomes. Although the pathologic diagnosis of HGSC is now made with high accuracy, there remain areas of disagreement regarding viewpoints on tissue site of origin and designation of primary site, with impact on staging in low-stage cases, as well as difficulties in reproducible and clinically relevant reporting of HGSC in specimens taken after neoadjuvant chemotherapy. These areas are discussed in the current article.

[Biopathology of ovarian carcinomas early and advanced-stages: Article drafted from the French guidelines in oncology entitled "Initial management of patients with epithelial ovarian cancer" developed by FRANCOGYN, CNGOF, SFOG, GINECO-ARCAGY under the aegis of CNGOF and endorsed by INCa]

OBJECTIVES

Ovarian carcinomas represent a heterogeneous group of lesions with specific therapeutic management for each histological subtype. Thus, the correct histological diagnosis is mandatory.

MATERIAL AND METHODS

References were searched by PubMed from January 2000 to January 2018 and original articles in French and English literature were selected.

RESULTS AND CONCLUSIONS

In case of ovarian mass suspicious for cancer, a frozen section analysis may be proposed, if it could impact the surgical management. A positive histological diagnosis of ovarian carcinoma (type and grade) has to be rendered on histological (and not cytological) material before any chemotherapy with multiples and large sized biopsies. In case of needle biopsy, at least three fragments with needles>16G are needed. Histological biopsies need to be formalin-fixed (4% formaldehyde) less than 1h after resection and at least 6hours fixation is mandatory for small size biopsies. Tissue transfer to pathological labs up to 48hours under vacuum and at +4°C (in case of large surgical specimens) may be an alternative. Gross examination should include the description of all specimens and their integrity, the site of the tumor and the dimension of all specimens and nodules. Multiples sampling is needed, including the capsule, the solid areas, at least 1 to 2 blocks per cm of tumor for mucinous lesions, the Fallopian tube in toto, at least 3 blocks on grossly normal omentum and one block on the largest omental nodule. WHO classification should be used to classify the carcinoma (type and grade), with the use of a panel of immunohistochemical markers. High-grade ovarian carcinomas (serous and endometrioid) should be tested for BRCA mutation and in case of a detectable tumor mutation, the patient should be referred to an oncogenetic consultation.

Neoadjuvant therapy in gynaecological malignancies: What pathologists need to know

In recent times, there has been a growing tendency to treat advanced gynaecological malignancies with neoadjuvant chemotherapy (NACT), with the goal of reducing tumour volume and enhancing operability resulting in optimal cytoreduction. This approach is used in particular for patients with advanced high-grade serous carcinoma of the ovary, fallopian tube or peritoneum. Pathology plays a crucial role in the management of these patients, both before and after NACT. Prior to initiation of NACT, a biopsy should be performed, usually of the omental cake, to confirm that a malignancy is present, to identify the site of origin of the tumour and to type and grade the tumour. Histopathologists must be aware of the resultant morphological effects of NACT when examining specimens following interval cytoreduction surgery. Tumour typing and grading, and even the identification of residual neoplasia, are particular challenges. Immunohistochemistry, when used judiciously, can be a useful adjunct in certain scenarios. A pathological assessment of the response to chemotherapy, and the pathological stage should be provided in the pathology report, as these may inform prognosis and subsequent management. We present a comprehensive overview of the relevant clinical and pathological aspects pertaining to NACT for gynaecological malignancies for the practicing surgical pathologist.

Interpretation of P53 Immunohistochemistry in Endometrial Carcinomas: Toward Increased Reproducibility

P53 immunohistochemistry has evolved into an accurate surrogate reflecting the underlying TP53 mutation status of a tumor, and has utility in the diagnostic workup of endometrial carcinomas. Recent work predominantly carried out in tubo-ovarian high-grade serous carcinoma has revealed 4 main patterns of p53 staining (normal/wild-type, complete absence, overexpression, and cytoplasmic); the latter 3 patterns are variably termed abnormal/aberrant/mutation-type and are strongly predictive of an underlying TP53 mutation. The aim of this review is to provide practical advice to pathologists regarding various aspects of p53 immunohistochemical staining. These include laboratory methods to optimize staining, a description of the different patterns of staining, advice regarding the interpretation, and reporting of p53 staining and practical uses of p53 staining in endometrial carcinoma diagnosis. Illustrations are provided to aid in the interpretational problems.

Suppressed OGT expression inhibits cell proliferation while inducing cell apoptosis in bladder cancer

Background

This study aimed to explore hyper-O-linked N-acetylglucosaminylation (O-GlcNAcylation) with an elevation of the expression of O-linked-β-N-acetylglucosamine transferase (OGT) in human bladder cancer.

Methods

Immunohistochemical staining for OGT and O-GlcNAcylation was performed in 20 paired human bladder cancer and adjacent normal tissues, as well as in human bladder cancer tissue microarrays (N = 169). The expression level of OGT and O-GlcNAcylation in cell lines were detected using the Western blot analysis. The effects of O-GlcNAcylation on the cell proliferation of bladder cancer were detected using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and clone formation assays. Cell apoptosis and cell cycle analysis were detected using flow cytometry. The autophagy of bladder cancer cells was investigated using the Western blot analysis, and GFP–LC3 plasmid was used to detect the autophagic flux. MTT assay was performed to detect the sensitivity of bladder cancer cells to cisplatin after OGT knockdown.

Results

The expression of OGT and the O-GlcNAcylation were upregulated in bladder cancer tissues and cell lines. O-GlcNAcylation and OGT were observed in nucleus and cytoplasm and found to be higher in muscle-invasive bladder cancer (MIBC) than in non-muscle-invasive bladder cancer (NMIBC). Reducing hyper-O-GlcNAcylation by OGT knockdown inhibited the proliferation of bladder cancer cells in vitro and xenograft tumor growth in vivo, triggered apoptosis, as well as led to cell cycle arrest. It also increased autophagy in bladder cancer cells. This study demonstrated increased autophagy pro-survival, but not pro-death. Reducing hyper-O-GlcNAcylation by OGT knockdown facilitated the chemosensitivity of bladder cancer cells to cis-platinum.

Conclusions

The data indicated that hyper-O-GlcNAcylation enhanced oncogenic phenotypes and was involved in DNA damage response in bladder cancer.

A Cell Line-based Immunohistochemical p53 Expression Pattern Control Panel

TP53 gene mutations are known to manifest in distinct p53 immunohistochemical staining patterns; overexpression, wild-type, and null. These stratified staining patterns are routinely utilized in subtyping ovarian cancer subtypes. Three ovarian cancer cell lines were used in the construction of an immunohistochemical p53 expression pattern control panel that highlight respective TP53 mutation status. The cell line control panel sections demonstrated consistent clean and easily interpretable p53 immunohistochemical staining. Procured resection, biopsy, and cytologic specimens were submitted along with either standard control tissue or a p53 cell line control panel to pathologists of varying experience for interrater reliability analysis. Individual interrater reliability was near-perfect and was improved with the p53 cell line control panel when compared with the tissue control. The cell line control panel demonstrated decreased misinterpretation of null expression pattern as wild-type. Next-generation sequencing analysis was performed on the cell lines and select cases, in which there was discordance in p53 expression pattern interpretation. Next-generation sequencing analysis demonstrated low-frequency variant mutations in some cases in which there was reviewer discordance. This study suggests the addition of a p53 cell line expression pattern control panel could potentially increase p53 interpretation accuracy for ovarian cancer subtypes. We developed a cell line-based p53 control panel that has the potential to increase individual interrater reliability for p53 immunohistochemical expression pattern determination, support immunohistochemical optimization, and direct submission of difficult to interpret p53 staining cases to next-generation sequencing.