P53 Staining Pattern Research Articles

Utility of IMP3, p53, and S100P immunohistochemical stains in distinguishing reactive atypia from dysplasia in cholecystectomy specimens

BackgroundDistinguishing reactive atypia from dysplasia in cholecystectomy specimens can be histologically challenging. The aim of this study was to evaluate the utility of IMP3, p53, and S100P immunostains in differentiating reactive atypia from dysplasia in cholecystectomies.MethodsFifty-four cholecystectomies were reviewed and characterized into 5 groups: 2 normal, 29 reactive atypia, 16 low-grade dysplasia, 2 high-grade dysplasia, and 5 adenocarcinoma. IMP3, p53, and S100P immunostains were performed and evaluated. IMP3 (nuclear) and S100P (nuclear or nuclear/cytoplasmic) were categorized into negative or positive expression, and p53 was categorized into wild-type and aberrant/mutant expression. Chi-square test was used for statistical analysis.ResultsThe patients were mostly middle-aged women (mean 44, range 19–87 years, 81% female), with predominantly Hispanic White ethnicity (80%). The majority of the normal and reactive atypia cases showed negative IMP3 (100% and 75.9%, respectively) and wild-type p53 (100% and 89.7%, respectively) staining. Over half (56.3%) of the low-grade dysplasia and all the high-grade dysplasia cases showed IMP3 positivity. Aberrant p53 staining pattern was seen in half of both low and high-grade dysplasia cases. Adenocarcinoma showed IMP3 positivity in 80% and p53 aberrancy in all cases. S100P showed no statistical significance among the diagnostic categories. Significant differences in staining patterns were found between reactive atypia vs. low-grade dysplasia, and reactive atypia vs. low-grade + high-grade dysplasia using a combination of IMP3 and p53 stains (all p < 0.05).ConclusionsIn challenging cholecystectomies, IMP3 positivity or aberrant p53 expression may serve as a useful adjunct to support a diagnosis of dysplasia over reactive atypia.

P53 Immunohistochemistry staining patterns and prognosis significance in 212 cases of non-endometrioid endometrial cancer

ObjectiveTo investigate the immunohistochemistry (IHC) staining pattern and prognostic significance of p53 in non-endometrioid endometrial cancer (non-EEC). MethodsThis study retrospectively included 212 non-EEC patients, with histological types including serous carcinoma (SC), clear cell carcinoma (CCC), mixed carcinoma (MC), undifferentiated carcinoma (UC), and carcinosarcoma (CS). p53 IHC was interpreted as normal/wild-type and abnormal/mutant-type, the latter including overexpression, complete absence, and cytoplasmic staining patterns. Moreover, uncommon p53 subclonal/heterogeneous staining patterns were described. Disease-free survival (DFS) and overall survival (OS) were employed as endpoints to evaluate the prognostic significance of p53. ResultsIn 212 non-EEC cases, 50 (23.6 %) were p53 wild-type, while 162 (76.4 %) displayed abnormal p53 staining. Overexpression was the predominant abnormal p53 staining pattern (122/162), complete absence followed (33/162). All SCs exhibited the mutant p53 staining pattern. The p53 abnormal expression rates in CCC, MC, UC, and CS were 37.5 %, 78.9 %, 35.7 %, and 75.7 %, respectively. Interestingly, of the 12 MC cases with SC components, barring one with p53 subclonal staining, all showed the mutant-type staining. The concordance rate for p53 expression between epithelial and mesenchymal components of CS was 94.3 % (66/70). Kaplan-Meier curves indicated patients with p53 abnormalities had worse DFS compared to those with wild-type p53 (P=0.025). Multivariate Cox regression confirmed that p53 (HR: 2.270, 95 % CI: 1.124–4.586, P=0.022) independently predicted DFS in non-EEC patients, though not for OS. ConclusionsNon-EEC patients with various histological types exhibit different p53 staining patterns. However, abnormal p53 expression, regardless of histological type, implies a poor DFS in non-EEC patients.

P53 Abnormal Oral Epithelial Dysplasias are Associated With High Risks of Progression and Local Recurrence—A Retrospective Study in a Longitudinal Cohort

Grading of oral epithelial dysplasia (OED) can be challenging with considerable intraobserver and interobserver variability. Abnormal immunohistochemical staining patterns of the tumor suppressor protein, p53, have been recently shown to be potentially associated with progression in OED. We retrospectively identified 214 oral biopsies from 203 patients recruited in a longitudinal study between 2001 and 2008 with a diagnosis of reactive, nondysplastic lesions, low-grade lesions (mild OED and moderate OED) and high-grade lesions (HGLs; severe OED/carcinoma in situ). Tissue microarrays were constructed from the most representative area of the pathology. Three consecutive sections were sectioned and stained for hematoxylin and eosin, p53 immunohistochemistry, and p16 immunohistochemistry. The staining results were reviewed by 2 pathologists (Y.C.K.K., C.F.P.) blinded to clinical outcome. Samples were categorized into p53 abnormal OED (n = 46), p53 conventional OED (n = 118), and p53 human papillomavirus (HPV) OED (HPV associated) (n = 12) using a previously published pattern-based approach. All cases of p53 HPV OED (HPV associated) were identified in HGLs. In contrast, cases of p53 abnormal OED were observed in mild OED (9.5%), moderate OED (23%), and severe OED/carcinoma in situ (51%). None of the 27 reactive or nondysplastic lesions showed abnormal p53 staining patterns. Among the 135 low-grade lesions, 23 cases (17.0%; 2 mild OEDs and 21 moderate OEDs) progressed to HGL or squamous cell carcinoma, with 11 cases showing progression within the first 3 years. Remarkably, 82% (9/11) of these faster progressors showed abnormal p53 patterns. Survival analysis revealed that p53 abnormal OED had significantly poorer progression-free probability (P < .0001) with hazard ratio of 11.24 (95% CI, 4.26-29.66) compared with p53 conventional OED. Furthermore, p53 abnormal OED had poorer local recurrence–free survival compared with p53 wild-type OED (P = .03). The study supports that OED with p53 abnormal pattern is at high risk for progression and recurrence independent of the dysplasia grade.

An extensive immunohistochemical analysis of 290 ovarian adult granulosa cell tumors with 29 markers.

The current knowledge about the immunohistochemical features of adult granulosa cell tumor (AGCT) is mostly limited to the "traditional" immunohistochemical markers of sex cord differentiation, such as inhibin, calretinin, FOXL2, SF1, and CD99. Knowledge about the immunohistochemical markers possibly used for predictive purpose is limited. In our study, we focused on the immunohistochemical examination of 290 cases of AGCT classified based on strict diagnostic criteria, including molecular testing. The antibodies used included 12 of the "diagnostic" antibodies already examined in previous studies, 10 antibodies whose expression has not yet been examined in AGCT, and 7 antibodies with possible predictive significance, including the expression of HER2, PD-L1, CTLA4, and 4 mismatch repair (MMR) proteins. The results of our study showed expression of FOXL2, SF1, CD99, inhibin A, calretinin, ER, PR, AR, CKAE1/3, and CAIX in 98%, 100%, 90%, 78%, 45%, 41%, 94%, 82%, 26%, and 9% of AGCT, respectively. GATA3, SATB2, napsin A, MUC4, TTF1, and CD44 were all negative. PTEN showed a loss of expression in 71% of cases and DPC4 in 4% of cases. The aberrant staining pattern (overexpression) of p53 was found in 1% (3/268) of cases, 2 primary tumors, and 1 recurrent case. Concerning the predictive markers, the results of our study showed that AGCT is microsatellite stable, do not express PD-L1, and are HER2 negative. The CTLA4 expression was found in almost 70% of AGCT tumor cells.

Correlation between immunohistochemical staining and clinicopathological findings in endometrial carcinoma.

To analyze the immunohistochemical staining pattern of mismatch repair (MMR) proteins and p53 in endometrial carcinoma cases, including different subtypes and stages, to gain insights into their role in the pathogenesis and clinical behaviour of this malignancy. In this study, we investigate the association between MMR deficiency, p53 mutational status, and clinical outcomes in various subtypes of endometrial carcinoma. The immunohistochemical staining pattern of MMR proteins in 96 cases of endometrial carcinoma have been analyzed, including 72 endometrioid, 14 papillary serous, 5 clear cell, and 5 mixed Müllerian tumor. The results showed that 36 cases were MMR deficient, with the majority being of endometrioid subtype. The p53 immunostain showed a mutational pattern in a subset of cases, with a documented dismal prognosis. However, aforementioned stains failed to predict synchronous or metachronous cancers in 5 patients. These findings highlight the importance of MMR and p53 immunohistochemical staining in the classification, and prognosis of endometrial carcinoma.

Morphologic and Molecular Heterogeneity of High-grade Serous Carcinoma Precursor Lesions.

Serous tubal intraepithelial carcinoma (STIC) is the fallopian tube precursor lesion for most cases of pelvic high-grade serous carcinoma (HGSC). To date, the morphologic, molecular, and clinical heterogeneity of STIC and a less atypical putative precursor lesion, termed serous tubal intraepithelial lesion, has not been well characterized. Better understanding of precursor heterogeneity could impact the clinical management of women with incidental STICs (without concurrent carcinoma) identified in cases of prophylactic or opportunistic salpingectomy. This study analyzed morphologic and molecular features of 171 STICs and 21 serous tubal intraepithelial lesions. We assessed their histologic features, Ki-67 and p53 staining patterns, and genome-wide DNA copy number alterations. We classified all precursor lesions into 2 morphologic subtypes, one with a flat surface (Flat) and the other characterized by budding, loosely adherent, or detached (BLAD) morphology. On the basis of pathology review by a panel of 8 gynecologic pathologists, we found 87 BLAD, 96 Flat, and 9 indeterminate lesions. As compared with Flat lesions, BLAD lesions were more frequently diagnostic of STIC ( P <0.0001) and were found concurrently with HGSC ( P <0.0001). BLAD morphology was also characterized by higher Ki-67 proliferation index ( P <0.0001), presence of epithelial stratification ( P <0.0001), and increased lymphocyte density ( P <0.0001). BLAD lesions also exhibited more frequent DNA copy number gain/amplification at the CCNE1 or CMYC loci canonical to HGSCs ( P <0.0001). Both BLAD morphology and STIC diagnoses are independent risk factors for an elevated Ki-67 proliferation index. No correlation was observed between BLAD and Flat lesions with respect to patient age, presence of germline BRCA1/2 mutation, or p53 staining pattern. These findings suggest that tubal precursor lesions are morphologically and molecularly heterogeneous, laying the foundation for further studies on the pathogenesis of HGSC initiation and identifying histologic features predictive of poor patient outcomes.

Diagnostic Usefulness of p53 Immunostaining in Gastric Cancer and Dysplasia: A Real-world Clinical Experience.

Gastric cancer and its precancerous lesions represent a significant public health concern. A subset of gastric cancers exhibits mutations in the TP53 gene, often accompanying distinctive morphologic alterations. This study aimed to assess the diagnostic efficacy of p53 immunostaining in real-world clinical settings. A retrospective analysis was conducted on 50 cases of gastric tumors and tumor-like lesions, wherein p53 immunostaining played a pivotal diagnostic role. The staining pattern of p53 was examined in conjunction with clinicopathologic parameters. Mutant p53 staining pattern demonstrated a significant association with high-grade nuclear atypia (p<0.001), high-grade dysplasia, and tubular adenocarcinoma (p<0.001), as well as microsatellite instability status (p=0.034). Furthermore, the diagnostic utility of p53 immunostaining was evident in scenarios where: 1) biopsy specimens contained few tumor cells, 2) pathologic evaluation of resection margins was limited by cauterization artifacts, and 3) distinction between low-grade and high-grade gastric dysplasia was challenging. P53 immunostaining can be helpful for the diagnosis of gastric tumor and tumor-like lesions, and accurate pathologic margin evaluation, particularly in lesions demonstrating intestinal-type differentiation and some degree of nuclear atypia.

Clinicohistopathological Features and Immunohistochemical Expression Patterns of p53 in Epithelial Ovarian Tumours: A Cross-sectional Study

Introduction: Ovarian tumours represent 3% of female malignancies, with epithelial tumours constituting more than 90% of all ovarian cancers. Tumour suppressor gene 53 (TP53) mutations play an important role in the prognosis and treatment of ovarian cancer. The tumour suppressor gene Tumour Protein 53 (p53), located on the short arm of chromosome 17, acts by suppressing abnormal cell growth at the beginning of the Synthesis phase (S-phase) of the cell cycle. Previous studies have shown a correlation between p53 mutation or overexpression and patient prognosis in various types of tumours, including breast cancer, rectal cancer, intestinal cancer, lung cancer, and ovarian cancer. Aim: To investigate the clinicohistopathological features and immunohistochemical expression of p53 in Epithelial Ovarian Tumours (EOT). Materials and Methods: A cross-sectional study was conducted in the Department of Pathology at Hind Institute of Medical Sciences, Barabanki, Uttar Pradesh, India. The duration of the study was one year and two months, from September 2021 to November 2022. A total of 80 cases of EOT were included and histopathological diagnosis was performed, and immunohistochemical expression of p53 was evaluated in all cases. The Chi-square test was used to compare categorical data (the number of benign, borderline, and malignant EOT) and determine whether the difference in p53 expression (positive or negative) was statistically significant, using Statistical Package for the Social Sciences (SPSS) version 26.0. Results: The total of 80 cases of EOT in the present study comprised 56 (70%) benign, 5 (6.25%) borderline, and 19 (23.75%) malignant tumours. The p53 expression was statistically significant. Immunohistochemistry (IHC) for p53 showed diffuse strong positive nuclear staining (&gt;60%) of the tumour cells in 14 cases, all of which were malignant epithelial tumours. Focally weak and patchy positive nuclear staining patterns (5%-60%) were observed in 64 cases, including 56 benign cases, four borderline cases, and four cases of malignant epithelial tumours, respectively. p53 positivity (&lt;5% staining of tumour cells) was seen in two cases, one each of borderline and malignant epithelial tumour, respectively. Conclusion: The IHC marker p53 serves as a surrogate marker for p53 gene mutation, and its positivity is observed in serous EOT. Understanding p53 staining patterns can be used in conjunction with a panel of other antibodies to correctly classify morphologically confusing EOT. This can aid in assessing prognosis and understanding the biological behaviour of the tumour, which can be helpful in modifying the treatment plan.

Comparative analysis of EZH2, p16 and p53 expression in uterine carcinosarcomas.

Introduction: The role of p16 and p53 immunohistochemistry in the diagnosis of rare and aggressive uterine carcinosarcoma (UCS) has been well established. However, enhancer of zeste homolog 2 (EZH2), a histone methyltransferase and a member of the polycomb group family is a relatively new biomarker, with limited published data on its significance in this tumor type. The goal of this study was to examine EZH2 expression in UCS and its components, in correlation with morphological features, and p16 and p53 staining patterns. Methods: Twenty-eight UCSs were included in the study. EZH2, p16 and p53 immunoreactivity were assessed independently by two pathologists in both tumor components (epithelial and mesenchymal). EZH2 and p16 immunostains were scored semiquantitatively: based on the percentage and intensity of tumor cell staining a binary staining index ("high- or low-expressing") was calculated. The p53 staining pattern was evaluated as wild-type or aberrant (diffuse nuclear, null, or cytoplasmic expression). Statistical tests were used to evaluate the correlation between staining patterns for all three markers and the different tumor components and histotypes. Results: High EZH2 and p16 expression and aberrant p53 patterns were present in 89.3% 78.6% and 85.7% of the epithelial component and in 78.6%, 62.5% and 82.1% of the mesenchymal component, respectively. Differences among these expression rates were not found to be significant (p > 0.05). Regarding the epithelial component, aberrant p53 pattern was found to be significantly (p = 0.0474) more frequent in the serous (100%) than in endometrioid (66.6%) histotypes. Within the mesenchymal component, p53 null expression pattern occurred significantly (p = 0.0257) more frequently in heterologous sarcoma components (71.4%) compared to the homologous histotype (18.8%). Conclusion: In conclusion, EZH2, p16 and p53 seem to play a universal role in the pathogenesis of UCS; however, a distinctive pattern of p53 expression appears to exist between the serous and endometrioid carcinoma components and also between the homologous and heterologous sarcoma components.

Pleomorphic Adenoma With Cystic Change, Extensive Squamous Metaplasia and Positive Block-Like p16 Staining Pattern: A Sheep In Wolf’s Clothing

Abstract Introduction/Objective Pleomorphic adenoma, the most common benign salivary gland neoplasm may show squamous metaplasia in up to 25% of cases, and less frequent cystic change. We report an unusual case of pleomorphic adenoma with cystic change, extensive squamous metaplasia and block-like p16 staining that was misdiagnosed as metastatic p16-positive squamous cell carcinoma in a limited core biopsy. Methods/Case Report A 78-year-old female with no history of malignancy presented with a right neck painless mass. PET-CT demonstrated a hypermetabolic ovoid mass adjacent to the right submandibular gland measuring 1.7 cm concerning for metastatic disease within a lymph node. Fine needle aspiration of lesion was hypocellular and showed cystic contents and rare atypical squamoid cells. Core biopsy of the lesion demonstrated sheets of squamoid cells with mild to moderate cytologic atypia in a hyalinized fibrotic stroma. Immunostain for p16 showed cytoplasmic and nuclear block-staining pattern. The biopsy was diagnosed as metastatic p16-positive squamous cell carcinoma. Subsequent human papilloma virus (HPV) in situ hybridization for low- and high-risk types was negative. The patient underwent right level 1B neck dissection revealing a pleomorphic adenoma arising at the periphery of the submandibular gland with cystic change and extensive central squamous metaplasia. Repeated p16 staining showed diffuse positivity in the area with squamous metaplasia and heterogenous staining in the non-metaplastic areas. Cobas HPV-PCR test covering 14 high-risk HPV subtypes was also negative. Results (if a Case Study enter NA) NA Conclusion We describe the unusual coexistence of extensive squamous metaplasia, cystic change and aberrant p16 staining pattern in an exophytic pleomorphic adenoma to raise awareness of how these changes individually, and more so in combination can mimic squamous cell carcinoma. The mechanism of p16 overexpression in metaplastic PAs appears to be independent of HPV infection.

Early Identification of TP53 mutation in Myelodysplastic Neoplasms and Acute Myeloid Leukemia Via Point-of-Care p53 Immunohistochemistry

Background: Myelodysplastic neoplasms (MDS) and acute myeloid leukemia (AML) are heterogeneous diseases that often carry a poor prognosis. Once MDS or AML is diagnosed, first-line therapy choices include hypomethylating agent/venetoclax, induction chemotherapy, and/or targeted therapeutics as appropriate. Traditional “7+3” induction therapy has limited efficacy in in patients with TP53 disruption. Mutations in TP53 occur in at least 8% of de novo AML genomes, but turnaround time for next-generation sequencing (NGS) can be 10-14 days. Hence, it is possible that patients with TP53 mutation(s) will receive a regimen that will not be effective as it will not be known whether a patient has a TP53 mutation soon after diagnosis. Furthermore, health care disparities are amplified by the lack of readily available precision diagnostics in low- and middle-income countries (LMIC), leading to worse outcomes. Early identification of TP53 mutation through p53 immunohistochemistry (IHC) testing might allow for more timely prognostication and intervention. Methods: The UMass Chan Leukemia Registry and UMass Hematopathology archives identified patients with MDS or AML with TP53 disruption between 2011 and 2023. Immunohistochemical staining for p53 was performed on sections of bone marrow core biopsies by VENTANA CONFIRM anti-p53 (DO-7) primary antibody. Images were scored by manual counting by at least 2 separate hematopathologists. TP53 mutational analysis was performed as previously described (Patel SA , ..., Gerber JM. Leuk Lymphoma 2021; 62: 3348-60). For TP53 exome sequencing, the entire coding region from codons 1-393 of isoform A were covered, with coverage depth &amp;gt; 500X. The concordance between p53 IHC and the referent test ( TP53 mutational testing as the gold standard) was assessed. Results: Query of theUMass Leukemia Registry and UMass Hematopathology archives yielded 86 clinically annotated patients with MDS and AML with TP53 disruption. Among 42 patients with MDS (or its subentities) with TP53 disruption, 61 bone marrow biopsies had concurrently available data for p53 IHC and TP53 mutational testing. (Some cases were sequential biopsies from the same patient). Among 44 patients with AML (or its subentities) with TP53 disruption, 36 bone marrow biopsies had concurrently available data for p53 IHC and TP53 mutational testing. For patients with MDS with TP53 disruption, the sensitivity of p53 IHC testing was 68.1% and specificity was 93.3% (Panel A). For patients with AML with TP53 disruption, the sensitivity of p53 IHC testing was 75.8% and specificity was 100% (Panel B). Merged MDS and AML analysis showed sensitivity of 71.3% and specificity of 93.8%. When using a cutoff of ≥ 5% for p53 IHC testing, positive predictive value (PPV) was 100%. Conclusion: Our data show that p53 IHC testingdemonstrates high specificity and PPV but low sensitivity and negative predictive value (NPV), suggesting that IHC may be a valuable “rule-in” test. A cutoff value of ≥ 5% for IHC confers 100% PPV. This suggests that a positive IHC result may justify p53 IHC-adapted first-line choice of therapy, but a negative result does not exclude the possibility of TP53 mutation. IHC testing is a more cost-effective measure and is more readily available than NGS, which would make it an attractive alternative especially across global markets and in geographic regions marked by health care inequities, due to inability to access genomic testing. Limitations to our study include the relatively small sample size, as well as presence of TP53 mutations that prevent protein expression and thus prevent IHC positivity (i.e. stop codons and/or post-transcriptional modifications). Furthermore, results from our study may be distinct from other centers' studies given different inclusion criteria and non-uniform criteria for p53 staining analysis. However, our study retains value in that the use of a high-fidelity point-of-care p53 IHC staining method may lead to better outcomes with reduced financial toxicity and may inform first-line therapeutics if the IHC is positive. Further large-scale studies will be needed to confidently establish the p53 IHC staining method as the preferred surrogate for TP53 mutational testing. Additional work needs to be performed to assess the link between p53 staining pattern and TP53 allelic state. Earlier precision treatment may improve outcomes in this exceptionally high-risk population.

Is HPV-negative cervical carcinoma a different type of cervical cancer?

Human papillomavirus (HPV), which is known to play a very important role in genital area (vulva, vagina, and cervix) cancers in women, is responsible for almost all cervical cancers. However, a significant proportion of cervical carcinomas (approximately 7%) is HPV-negative. Therefore, there are still two important questions to be answered: 1. Why is HPV Deoxyribonucleic acid (DNA) not found in all cervical carcinomas? 2. Are HPV-DNA-negative cervical cancers a specific subgroup of cervical cancers with different biological behavior (worse prognosis)? In this article, we aimed to evaluate the clinicopathological characteristics and survival of patients with confirmed HPV-negative tumors in order to answer these two questions. A total of 97 patients who underwent HPV-DNA testing and received a histological diagnosis of cervical cancer were included in the study. 14 HPV-DNA negative and 83 HPV-DNA positive cervical carcinoma patients were detected. Demographic profiles, clinicopathological characteristics, progression-free, and overall survival of all patients were analyzed. Women with HPV-negative tumors were diagnosed at an older age range (p=0.05), and their demographic data other than age range were similar to HPV-positive tumors. P16 staining pattern was not observed in any of the HPV-negative tumors (p=0.001), and a positive P53 staining pattern was detected in 35.7% of the HPV-negative tumors. Although disease-free survival (PFS) (p=0.224) and overall survival (OS) (p=0.219) were worse in the HPV-negative patient group, this difference was not statistically significant. HPV-negative cervical cancers do not have a poor prognosis unlike their counterparts in other anatomical regions where HPV-associated tumors are present.

The fading guardian: clinical relevance of TP53 null mutation in high-grade serous ovarian cancers.

we evaluated the concordance between immunohistochemical p53 staining and TP53 mutations in a series of HGSOC. Moreover, we searched for prognostic differences between p53 overexpression and null expression groups. patients affected by HGSOC were included. For each case p53 immunohistochemical staining and molecular assay (Sanger sequencing) were performed. Kaplan-Meier survival analyses were undertaken to determine whether the type of TP53 mutation, or p53 staining pattern influenced overall survival (OS) and progression free survival (PFS). 34 HGSOC were considered. All cases with a null immunohistochemical p53 expression (n=16) showed TP53 mutations (n=9 nonsense, n=4 in-frame deletion, n=2 splice, n=1 in-frame insertion). 16 out of 18 cases with p53 overexpression showed TP53 missense mutation. Follow up data were available for 33 out of 34 cases (median follow up time 15 month). We observed a significant reduction of OS in p53 null group [HR = 3.64, 95% CI 1.01-13.16]. immunohistochemical assay is a reliable surrogate for TP53 mutations in most cases. Despite the small cohort and the limited median follow up, we can infer that HGSOC harboring p53 null mutations are a more aggressive subgroup.

Aberrant p16, p53 and Ki-67 immunohistochemistry staining patterns can distinguish solitary keratoacanthoma from cutaneous squamous cell carcinoma

Keratoacanthoma (KA) is widely considered a benign, usually self-resolving, neoplasm distinct from cutaneous squamous cell carcinoma (cSCC), while some consider KA to be indistinguishable from cSCC. Published studies indicate utility for p16, p53, Ki-67 immunostaining and elastic van Gieson (EVG) in the assessment of KA and cSCC. We compared clinical features and staining patterns for p16, p53, Ki-67 and EVG in fully excised KA, cSCC with KA-like features (cSCC-KAL) and other cSCC (cSCC-OTHER). Significant differences between KA, cSCC-KAL and cSCC-OTHER were found for head and neck location (20%, 86%, 84%), and duration <5 months (95%, 63%, 36%). KA shows both a mosaic pattern for p16 (>25-90% of neoplasm area) and peripheral graded pattern for p53 (up to 50% moderate and strong nuclear staining) in 92% compared with 0% of cSCC-KAL and 0% of cSCC-OTHER. In contrast, a highly aberrant pattern (usually null) for one or both p16 and p53, was present in 0% of KA, 83.8% of cSCC-KAL and 90.9% of cSCC-OTHER. Abnormal distribution of Ki-67 beyond the peripheral 1-3 cells was uncommon in KA (4.2%) and common in cSCC-KAL (67.6%) and cSCC-OTHER (88.4%). Moderate to striking entrapment of elastic and collagen fibres was present in the majority of KA (84%), cSCC-KAL (81%) and cSCC-OTHER (65%). KA are clinically distinct neoplasms typically of short duration occurring preferentially outside the head and neck and generally lacking aberrations of p16, p53 and Ki-67, compared with cSCC that have high rates of aberrant or highly aberrant p16, p53 and Ki-67, but EVG lacked specificity.

High-grade Serous Carcinoma can Show Squamoid Morphology Mimicking True Squamous Differentiation.

Tubo-ovarian high-grade serous carcinoma (HG-SC) and ovarian endometrioid carcinoma (EC) can show overlapping morphologic features, such as glandular and solid patterns. The differential diagnosis of these subtypes is thus sometimes difficult. The existence of "squamous differentiation" tends to lead to a diagnosis of EC rather than HG-SC. We noticed that HG-SC can contain a "squamoid component," but its nature has been poorly investigated. This study was thus established to clarify the nature of this "squamoid component" in HG-SC by investigating its frequency and immunohistochemical features. We reviewed hematoxylin and eosin-stained slides of 237 primary untreated cases of tubo-ovarian HG-SC and identified 16 cases (6.7%) of HG-SC with "squamoid component." An immunohistochemical staining panel (CK5/6, CK14, CK903, p40, p63, WT1, ER, and PgR) was used to analyze all of these 16 cases. We also selected 14 cases of ovarian EC with "squamous differentiation" as a control. The "squamoid component" in HG-SC was completely p40-negative and showed significantly lower expression of CK5/6, CK14, CK903, and p63 than the "squamous differentiation" in EC. The immunophenotype of the "squamoid component" in HG-SC was concordant with the conventional HG-SC component (WT1-positive/ER-positive). Furthermore, all 16 tumors were confirmed to be truly "HG-SC" by the findings of aberrant p53 staining pattern and/or WT1/p16 positivity, and the lack of mismatch repair deficiency and POLE mutation. In conclusion, HG-SC can on rare occasions show a "squamoid component" mimicking "squamous differentiation." However, the "squamoid component" in HG-SC does not represent true "squamous differentiation." The "squamoid component" is one part of the morphologic spectrum of HG-SC, which should be interpreted carefully for the differential diagnosis of HG-SC and EC. An immunohistochemical panel including p40, p53, p16, and WT1 is a useful adjunct to achieve a correct diagnosis.

Spectrum, Clinicopathologic Profile, and p16 Expression Pattern of Nonmalignant Cervical Tissues in Enugu, South-East Nigeria

Abstract Background p16 is a marker for p16-induced transformation of high-risk human papilloma virus (hrHPV)-infected cervical epithelium. HPV is a known etiologic agent of cervical cancer. Persistent hrHPV infection of cervical epithelium causes transformation of the infected epithelial cells resulting in increased proliferative potential of the cells and subsequent progression to frank malignancy. Early detection of transformation in cervical cells is crucial in reducing morbidity and mortality associated with cervical cancer. Materials and Methods We aimed to study the clinicopathologic profile of nonmalignant cervical lesions and their p16 staining pattern. Histopathology requisition forms, blocks, and slides of cases containing cervical tissue with nonmalignant diagnosis received into the morbid anatomy department of University of Nigeria Teaching Hospital, Enugu, from 2009 to 2018 were studied. Fresh sections from the blocks were immunohistochemically stained with p16 and examined. Results One-hundred and ninety-one cases were studied. Majority of the cases are normal cervical epithelium. Chronic nonspecific cervicitis was the major non-neoplastic lesion present and accounted for 33.3% of the biopsy and the mean age was 50.5 years. Other lesions were nabothian cyst (8.4%), cervical polyp (10.5%), low-grade and high-grade squamous intraepithelial lesion (LSIL and HSIL; 6.3 and 2.6%, respectively). The mean age for LSIL was 40.3 years, while that of HSIL was 45.2years. Four LSIL, two HSIL, one polyp, one chronic nonspecific cervicitis, and one lobular endocervical hyperplasia stained positively with p16. Conclusion The most common benign lesion of the cervix is cervicitis. Chronic cervicitis is negative to p16 immunoreactivity. There are more low-grade cervical intraepithelial neoplasia (CIN) than high-grade CIN. The low-grade CIN overexpress p16 in one-third of cases. There are more cases of p16-negative high-grade CIN in this study.

A DMBA-induced ovarian cancer model: Could it be clinically useful to test OncoTherad and erythropoietin as anticancer approaches?

e17589 Background: The term ovarian carcinoma (OC) refers to a heterogeneous collection of five distinct diseases known as histotypes. While histotype-specific treatment is still a clinical challenge, well-characterized models are required for testing new therapies. OncoTherad is a nanoimmunotherapy developed by University of Campinas/Brazil, which exhibits antitumor properties. Erythropoietin (EPO) has cytoprotective effects including in the ovaries. We assessed whether a chemically-induced animal OC model was representative of human disease by evaluating which histotype it best represents. We evaluated both mutational and immunohistochemical (IHC) biomarkers routinely used for human OC and used the observed features to provide context in the evaluation of OncoTherad and EPO effects. Methods: Thirty-five Fischer rats were distributed into 5 groups: Control (Sham surgery); Cancer (7,12-dimethylbenzoanthracene – DMBA injection in the ovarian bursa, 1.25 mg/kg); OncoTherad (20mg/kg IP); EPO (8.4 µg/kg IP); and OncoTherad+EPO (same doses). Ovary specimens were formalin-fixed into paraffin-embedded donor blocks. After DNA extraction and tissue microarray construction, we assessed typical gene mutations directly by Sanger sequencing (Pik3ca, Ctnnb1, and Kras) or indirectly using IHC surrogates (Arid1a and p53). Finally, we examined biomarkers typical of different OC histotypes (Wt1, Pr, Hnf1β) as well as lymphocyte density (CD3) by IHC. Results: The results were consistent across the cancer-induced animals. The majority of abnormal epithelial cells were Wt1+, Pr-, and Hnf1b-. Therefore, our rat model of DMBA-induced ovarian cancer was most likely serous type ovarian carcinoma, in agreement with the histopathological analysis. The ovarian lesions were molecularly similar to low-grade serous ovarian carcinoma as abnormal pattern of p53 staining was rarely observed. Loss of immunoreactivity for Arid1a protein was seen in some abnormal epithelium. However, the interpretability of mutation surrogates in rat tissues may not always be consistent with IHC analysis systems applied for human tissues. Furthermore, DNA sequencing did not reveal driver mutations in any of the sampled specimens. The treatments, especially OncoTherad+EPO, increased the number of CD3 positive immune cells. After EPO treatment, the tumor and abnormal areas showed a higher number of CD3+ lymphocytes than the normal regions; following a previous work, this could be due to substantial presence of Foxp3 positive cells. Conclusions: The features analyzed favored a low-grade serous carcinoma model in which treatments with OncoTherad and EPO showed immunomodulatory properties related to the reduction of ovarian lesions seen in previous work. The overall data highlight the importance of further characterizations of animal models to provide a complete and specific panel for testing new drugs.

P53 and PTEN expression evaluation with molecular evident recent criteria in laryngeal carcinoma.

The prognosis of laryngeal cancer is affected by clinicopathological factors. Because of that, an effective prognostic marker is very valuable in managing the clinical process. The p53 evaluation method, used in the literature recently, was used for the first time in laryngeal cancer. We evaluated PTEN with 2 methods with the highest significance in the literature on laryngeal cancer. All demographic and histopathological data from 140 laryngeal cancers were compared with p53 and PTEN expressions and survival. p53 staining patterns were classified as wild and mutant. PTEN expression was evaluated according to the staining intensity named PTEN1 and according to the proportion of stained cells named PTEN2. In the series, 93.6% were males, and the mean survival was 38 months. 69.3% of cases were p53 mutants. PTEN loss was found to be 85.7% and 57.9%, respectively. Tumor size and thyroid cartilage invasion for PTEN1 and age for p53 were identified as independent predictive factors (P < .01). Advanced age, total laryngectomy, and extranodal spread were independent poor prognostic factors for overall survival and the presence of subglottic involvement, perineural invasion, and extranodal spread were for disease-free survival (P < .01). This is the first study in which the new p53 classification was used in laryngeal cancer, and will contribute significantly to the literature with differences from the previous evaluation patterns. Evaluation of PTEN based on staining intensity is more appropriate compared to the percentage of stained cells.

The effect of P53 expression and smoking/alcohol in P16(+) and P16(–) oropharyngeal carcinoma and risk classification: the Turkish Society of Radiation Oncology Head & Neck Study Group 01-002

The aim of this study is to categorize the risk groups of patients with oropharyngeal carcinoma (OPC) according to p16 and p53 status, smoking/alcohol consumption history, and other prognostic factors. The immunostaining of p16 and p53 of 290 patients was retrospectively evaluated. The history of smoking/alcohol consumption of each patient was noted. p16 and p53 staining patterns were reviewed. The results were compared with demographic findings and prognostic factors. Risk groups have been classified for the p16 status of patients. The median follow-up was 47 months (range 6-240). Five-year disease-free survival (DFS) rates for patients with p16 (+) and (-) were 76% and 36%, and overall survival rates were 83% vs 40%, respectively (HR=0.34 [0.21-0.57], P < .0001), HR=0.22 [0.12-0.40] P < .0001, respectively). p16(-), p53(+), heavy smoking/alcohol consumption, performance status; advanced T and N stages in patients with p16(-), and continuing smoking/alcohol consumption after treatment were found to be unfavorable risk factors. Five-year overall survival rates were 95%, 78%, and 36% for low, intermediate, and high-risk groups, respectively. The results of our study have shown that p16 negativity in patients with oropharyngeal cancer was found to be an important prognostic factor, especially for those with lower p53 expression and not smoking/consuming alcohol.

Abstract 5555: Altered p53/p16 expression is linked to urothelial carcinoma progression but is unrelated to prognosis in muscle-invasive tumors

Abstract Background: Most inactivating p53 mutations result in a nuclear accumulation of the defective p53 protein. However, p53 alterations that result in a complete lack of cellular p53 and complete absence of p53 immunostaining do also occur. As p16 is upregulated in p53 inactivated cells, p16 immunohistochemistry may be a surrogate marker for p53 inactivation. Design: In this study, we investigated p53 and p16 immunostaining on more than 2,500 urothelial bladder carcinomas in a tissue microarray format to better understand their impact in relation to clinicopathological parameters of disease progression and patient outcome. Results: p16 immunostaining was not observed in normal urothelium but occurred in 1,576 (63.5%) of cancers including 755 (30.4%) with a strong staining. The fraction of p16 positive cases increased markedly from pTaG2 low grade (9.6%) to pTaG3 high grade tumors (46.5% strongly positive, p&amp;lt;0.0001 for pTaG2 low vs. pTaG3) but continuously decreased from pTaG3 to pT2 (41.3% strongly positive), pT3 (36.5%) and pT4 (33.3%; p=0.0030). Within pT2-4 carcinomas, p16 positivity was also linked to high grade (p=0.0005) but unrelated to overall survival. p53 staining has been recorded as negative in 203 (8.4%), very weak in 373 (15.4%), weak in 1,341 (55.3%), strong in 115 (4.7%), and very strong in 393 (16.2%) cancers. The fraction of tumors with negative (potentially p53 null phenotype), strong, and very strong p53 positivity increased markedly from pTaG2 low grade to pTaG3 high grade tumors (p&amp;lt;0.0001) and from pTaG3 to muscle-invasive pT2-4 cancers (p=0.0007). p53 staining pattern was unrelated to histopathological parameters of malignancy or patient prognosis within pT2-4 carcinomas, however. There was a significant overall association between p53 and p16 expression but strong p16 expression predominated in tumors with very strong, strong, and negative p53 staining. Subset analyses showed that the combination of p53 negative/p16 strongly positive cancers was particularly linked to features of tumor aggressiveness. Conclusion: Our data show that altered function of p53 and p16 immunostaining increases during grade and stage progression although these alterations lack prognostic significance in pT2-4 carcinomas. That high level p16 expression is limited to neoplastic urothelium and that the p53 null phenotype is largely limited to grade 3 and invasive urothelial carcinomas are features with potential diagnostic utility. Citation Format: Simon Schallenberg, Henning Plage, Sebastian Hofbauer, Kira Kornienko, Sarah Weinberger, Paul G. Bruch, Florian Roßner, Sefer Elezkurtaj, Martina Kluth, Maximilian Lennartz, Tim Mandelkow, Elena Bady, Niclas C. Blessin, Andreas H. Marx, Henrik Samtleben, Margit Fisch, Michael Rink, Marcin Slojewski, Krystian Kaczmarek, Thorsten Ecke, Steffen Hallmann, Stefan Koch, Nico Adamini, Sarah Minner, Ronald Simon, Guido Sauter, David Horst, Tobias Klatte, Thorsten Schlomm, Henrik Zecha. Altered p53/p16 expression is linked to urothelial carcinoma progression but is unrelated to prognosis in muscle-invasive tumors. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5555.