P16 Immunohistochemistry Research Articles

Morphomolecular Correlation and Clinicopathologic Analysis in Endometrial Carcinoma.

Research groups have identified 4 groups [polymerase epsilon (POLE) mutant, mismatch repair-deficient, p53-abnormal, and no specific molecular profile)] reflecting the Tumor Cancer Genomic Atlas Research Network subgroups in endometrial carcinomas, improving the clinical applicability of molecular classification. We have analyzed the histopathologic and prognostic characteristics of our cases based on the ProMisE classification, supported by growing data on recommended treatment regimens. The study included 118 cases of endometrial carcinoma diagnosed between 2016 and 2020, which underwent mismatch repair and p53 immunohistochemistry. Next-generation sequencing was performed for POLE mutation analysis, dividing the cases into 4 subgroups. The histopathologic and clinical characteristics of these groups were then analyzed statistically. Four cases(3.4%) were classified as POLE mutant, 31 (26.3%) as mismatch repair-deficient, 22 (18.6%) as p53 mutant, and 61 (51.7%) as no specific molecular profile. We categorized 118 patients with endometrial carcinoma into low (n=43), intermediate (n=28), high-intermediate (n=21), high (n=22), and advanced metastatic (n=4) risk groups regardless of the molecular subtypes of their disease. When we reclassified all cases according to the molecular subtypes of endometrial carcinoma only the risk group of 3 (2.5%) cases changed. Using the new algorithm we designed, after narrowing down the number of patients, the microcystic, elongated, and fragmented pattern of invasion was revealed as an independent prognostic factor that reduces overall survival time (hazard ratio: 16.395, 95% CI: 2.140-125.606, P =0.007). In conclusion, using the new algorithm we have designed, and by identifying patients for whom molecular classification could alter risk groups, we observed that molecular tests can be utilized more efficiently in populations with limited economic resources and, in doing so, we discovered a new morphologic marker with prognostic significance.

Outcomes of De Novo Oligometastatic Breast Cancer Treated With Surgery of Primary and Metastasis Directed Radiotherapy.

With sensitive imaging for breast cancer, the question arises whether present-day oncologists treat dOMBC with palliative systemic therapy (ST), which, a few years earlier, would have been treated with curative intent. We retrospectively analyzed outcomes of dOMBC treated with curative intent using a combination of surgery, metastasis-directed radiotherapy (RT), and adjuvant/neoadjuvant ST and have also explored the possible role of total lesional glycolysis of metastases and p53 immunohistochemistry in predicting outcomes. Data were collected from a prospectively maintained database using electronic medical records and Radiation Oncology Information System. In the study, dOMBC was defined as up to 3 metastatic sites, all amenable to treatment with ablative RT and primary and axillary disease amenable to curative surgery. Patients were treated with surgery, ST, and RT. Patients underwent either breast conservation surgery or modified radical mastectomy. Patients were treated with 6 to 8 cycles of chemotherapy in the neoadjuvant and/or adjuvant setting. Hormone receptor-positive patients received either tamoxifen or aromatase inhibitors. Trastuzumab was offered to Her-2-neu receptor-positive patients. RT included locoregional RT and metastases-directed ablative body RT. The median progression-free survival was 39 months (95% CI: -28.7 to 50.1mo). Two and 3 year estimated disease-free survival (DFS) was 79% and 60.5%, respectively. The median overall survival was not reached. The estimated 3-year overall survival was 87.3%. Total lesional glycolysis of metastases score and p53 status did not affect DFS. Combination treatment of surgery, metastases-directed ablative RT, and ST may provide prolonged DFS in dOMBC.

Human Papilloma Virus-Independent/p53abnormal Keratinizing Squamous Cell Carcinoma of the Uterine Cervix Associated With Uterine Prolapse.

Knowledge about the morphologic and molecular characteristics of cervical squamous cell carcinomas (CSCCs) associated with uterine prolapse is very limited. Detailed histopathological and immunohistochemical (p16, p53, and cytokeratin 17), as well as molecular evaluation for human papillomavirus (HPV)-DNA and p53-mutational analyses in 4 consecutive CSCCs associated with uterine prolapse with definition of a hitherto not well-described HPV-independent/p53abnormal precursor lesion (HPV-independent cervical intraepithelial neoplasia [CIN; differentiated CIN]) and molecular tumorigenetic pathway. Cases diagnosed within 7 years with a mean age of 75 (range: 69-83) years and a mean tumor size of 7.3cm (range: 5.2-9.4cm). All patients presented with locally advanced disease, and 1 woman died of the disease within 4, and another within 14 months of follow-up. All CSCCs and their adjacent precursor lesions were negative for p16, with aberrant p53-expression and diffuse and strong staining for cytokeratin 17. Both the CSCCs and their precursors were negative for HPV-DNA but harbored a TP53 mutation. The precursor lesions were characterized by epithelial thickening with superficial keratinization, and the presence of basal and parabasal keratinocytes with mitotic figures beyond the basal layer, thus showing features similar to those seen in differentiated types of vulvar intraepithelial lesions (vulvar intraepithelial neoplasia [VIN] syn. HPV-independent/p53abn VIN), suggesting the terminology of differentiated CIN or HPV-independent/p53abn CIN. An HPV-independent pathogenetic pathway with a p53-alteration was identified for these cases. CSCC associated with uterine prolapse represents HPV-independent tumors harboring a TP53 mutation. For the first time, a precursor lesion of HPV-independent CSCC of the uterine cervix is described with a differentiated VIN-like morphology, and a separate tumorigenic pathway defined.

Biomarker Expression and Clinical Outcomes in International Study of Chemoradiation and Magnetic Resonance Imaging-Based Image-Guided Brachytherapy for Locally Advanced Cervical Cancer: BIOEMBRACE

PurposeBIOEMBRACE-I was designed to study the impact of biomarkers in addition to clinic-pathological factors on disease outcomes in patients treated with chemoradiation and MRI-guided brachytherapy (BT) for locally advanced cervical cancer in EMBRACE study. Patient and MethodsBetween 2018-2021, eight EMBRACE-I sites contributed tumour tissue for immunohistochemistry of p16, PD-L1 and L1CAM. These biomarkers and clinicopathological factors (FIGO 2009 stage, nodal status, histology, necrosis on MRI) were analysed to predict poor response at brachytherapy (BT) (high-risk clinical target volume [HR-CTV] ≥40cc) at BT), and 5-year local control, pelvic control and disease-free survival (DFS). Interaction between p16, PD-L1, radiotherapy dose (HR-CTV D90) and disease outcomes was investigated. Univariable and multivariable analysis were performed. ResultsTwo-hundred sixty-four patients were included. The median HR-CTV D90 was 89 (86-95) Gy. p16 positive (pos), PD-L1>1% and L1CAM ≥ 10% was noted in 86.6%, 20.1% and 17.8% respectively. P16 negative (neg) status (OR 2.0 (1.0-5.7), p=0.04), necrosis on MRI (OR 2.1 (1.1-4.3), p<0.02) independently predicted for HR-CTV≥40cc, as did FIGO stage and tumour width >5cm. PDL1>1% was associated with reduced local (82% vs. 94%, p=0.02) and pelvic control (79% vs. 89%, p=0.02). HR-CTV D90 <85Gy was associated with inferior 5-year local control in p16+ patients especially if PD-L1 was co-expressed. On multivariable analysis, PD-L1>1% was the only independent factor for 5-year local control (HR 3.3, p=0.04) and L1CAM ≥50% for pelvic control (HR 5.5 (1.3-23.3), p =0.02). ConclusionsP16 neg status and tumor necrosis on MRI are independently associated with poor response to chemoradiation, whereas PD-L1>1% and L1CAM≥50% have an independent impact on local and pelvic control suggesting impact of biomarker expression on outcomes. Further validation is needed.

DNA Methylation and p53 Immunohistochemistry as Prognostic Biomarkers for Vulvar Lichen Sclerosus

Vulvar lichen sclerosus (LS) is an inflammatory dermatosis that can progress to human papillomavirus (HPV)-independent vulvar intraepithelial neoplasia (HPVi VIN) and vulvar squamous cell carcinoma (VSCC). Although LS has a much lower cancer risk compared with HPVi VIN (5% vs 50%, respectively), its incidence is significantly higher. Therefore, there is a clinical need to identify LS patients with an increased cancer risk. Our objective was to study the value of DNA methylation and p53 immunohistochemistry (IHC) as prognostic biomarkers for progression to cancer in patients with LS. Vulvar tissues from 236 patients were selected, including 75 LS and 68 HPVi VIN, both with and without cancer development, 32 VSCC, and 61 healthy vulvar controls. Samples were subjected to p53 IHC and DNA methylation analysis of a 3-gene marker panel containing ZNF582, SST, and miR124-2. Methylation levels and p53 IHC status (mutant or wild-type) were assessed and compared among all disease categories. Odds ratios were determined to identify whether the biomarkers were associated with progression to cancer in patients with LS. The highest methylation levels were found in HPVi VIN and VSCC, followed by LS and healthy vulvar controls. The largest heterogeneity in methylation levels was observed in LS cases. In fact, the 3-marker panel tested positive in 70% of LS, which progressed to VSCC vs only 17% of LS in patients without cancer development (P = .002). Also, mutant p53 IHC was observed more frequently in LS with progression to VSCC compared with nonprogressive LS cases (42% vs 3%, respectively, P = .001). Multivariable analysis identified a mutant p53 status as the only independent risk factor for cancer development in LS (odds ratio: 34.0, 95% CI: 1.4-807.4). In conclusion, DNA methylation testing and p53 IHC show strong potential as prognostic biomarkers for the identification of LS patients at high risk of progression to cancer.

Histopathologic and molecular profile of gliomas diagnosed in Lagos, Nigeria

Abstract Background The optimal diagnosis and management of patients with brain tumors currently uses the 2021 WHO integrated diagnosis of histomorphologic and molecular features. However, neuro-oncology practice in resource-limited settings usually relies solely on histomorphology. This study aimed to classify glioma cases diagnosed in the Department of Anatomic and Molecular Pathology, Lagos University Teaching Hospital, using the 2021 WHO CNS tumor classification. Methods Fifty-six brain tumors from 55 patients diagnosed with glioma between 2013 and 2021 were reevaluated for morphologic diagnosis. Molecular features were determined from formalin-fixed paraffin-embedded (FFPE) tissue using immunohistochemistry (IHC) for IDH1-R132H, ATRX, BRAF-V600E, p53, Ki67, and H3-K27M, OncoScan chromosomal microarray for copy number, targeted next generation sequencing for mutation and fusion and methylation array profiling. Results Of 55 central nervous system tumors, 3 were excluded from histomorphologic reevaluation for not being of glial or neuroepithelial origin. Of the remaining 52 patients, the median age was 20.5 years (range: 1 to 60 years), 38(73%) were males and 14(27%) were females. Seventy-one percent of the gliomas evaluated provided adequate DNA from archival FFPE tissue blocks. After applying the 2021 WHO diagnostic criteria the initial morphologic diagnosis changed for 35% (18/52) of cases. Diagnoses of 5 (9.6%) gliomas were upgraded, and 7 (14%) were downgraded. Conclusions This study shows that the incorporation of molecular testing can considerably improve brain tumor diagnoses in Nigeria. Furthermore, this study highlights the diagnostic challenges in resource-limited settings and what is at stake in the global disparities of brain tumor diagnosis.

Clinical Significance of Human Papillomavirus DNA Test and p16 Overexpression in Oropharyngeal Cancer

Background and Objectives Oropharyngeal squamous cell carcinoma (OPSCC) can be caused by human papilloma virus (HPV) infection or other factors like smoking. The 8th Edition of the AJCC Cancer Staging Manual recommends different staging and treatment approaches based on etiology. Despite criticisms of its low specificity, the current guidelines suggest using p16 immunohistochemistry (IHC) as a surrogate marker for the HPV-related OPSCC. This study assessed the reliability of p16 as a surrogate marker by correlating the survival rates of OPSCC patients with the results of p16 IHC and HPV-DNA testing.Subjects and Method A retrospective analysis was performed on patients treated for tonsil squamous cell carcinoma at a tertiary medical institution between 1994 and 2018. All patients underwent p16 immunostaining and HPV-DNA chip tests. Out of 88 patients, 17 were excluded due to insufficient data or secondary primary cancer, leaving 71 patients.Results Among the 71 patients, 51 were p16 positive and 49 were HPV-DNA positive; both tests were associated with extended survival. However, discrepancies were noted in 18 patients: specifically, 11 patients were p16 positive but HPV-DNA negative, displaying a different survival pattern compared to HPV-associated and non-HPV-associated patients.Conclusion Both p16 immunostaining and HPV-DNA testing have their pros and cons. p16 immunostaining is cost-effective but has lower specificity. The study found discrepancies in 18 patients, suggesting that relying solely on p16 immunostaining may have limitations. It would be advisable to complement it with additional tests like the HPV-DNA chip test to predict the disease’s prognosis more accurately.

P53 protein expression patterns associated with TP53 mutations in breast carcinoma

PurposeThe importance of a TP53 mutation has been demonstrated in several tumor types, including breast cancer (BC). However, the accuracy of p53 protein expression as a predictor of gene mutation has not been well studied in BC. Therefore, we evaluated p53 protein expression associated with TP53 mutations in breast cancers from 64 patients.MethodsTP53 mutation was examined using next-generation sequencing (NGS). p53 protein expression was examined using immunohistochemistry (IHC).ResultsAmong the 64 BCs, 55% demonstrated abnormal expression patterns including 27% overexpression, 22% null, 6% equivocal with 45% having a wild-type pattern. A TP53 mutation was present in 53% (34/64) of tumors including 30% (19/64) demonstrating a missense mutation, 11% (7/64) with a frameshift mutation, 11% (7/64) with a nonsense mutation, and 3% (1/64) with a splice site mutation. Abnormal expression of p53 protein was present in 33 of 34 (97%) tumors carrying a TP53 mutation; conversely, a wild-type pattern was present in 28 of 30 (93%) tumors without a detectable mutation (p < 0.0001). The majority of BCs with a p53 IHC overexpression pattern (15/17, 88%) contained a missense TP53 mutation; while the majority of BCs with a null pattern (12/14, 86%) contained a truncating mutation (p < 0.0001). The BCs with a null pattern are associated with a high Nottingham histological grade and a triple-negative phenotype when compared to those demonstrating overexpression (p < 0.05).ConclusionThese findings suggest that p53 IHC can be a potential surrogate for TP53 mutations in BC. Different p53 expression patterns may correlate with specific TP53 genetic mutations in BC.

PRAME and Historical Immunohistochemical Antibodies Ki-67, P16, and HMB-45 in Ambiguous Melanocytic Tumors.

Ambiguous melanocytic lesions/tumors (AMLs) can be simply described as melanocytic neoplasms that cannot be differentiated as either a melanoma or a nevus. Preferentially expressed antigen in melanoma (PRAME) is a novel antibody that can help differentiate between nevi and melanomas. However, its usefulness remains controversial in AMLs. The aim of this study was to demonstrate the importance of PRAME and diagnostic auxiliary antibodies (Ki-67, p16, HMB-45) in the diagnosis of melanocytic lesions, especially in AMLs. This study included 52 ambiguous melanocytic lesions, 40 nevi, and 40 melanomas. All immunohistochemical studies were performed automatically using the Universal Alkaline Phosphatase Red Detection Kit. Different analytic approaches were used for each antibody based on the literature. Statistically, the multinomial forward stepwise elimination logistic regression analysis was used to create a statistical model to predict the diagnosis of melanocytic lesions based on clinical, morphological, and immunohistochemical data. PRAME positivity was very strong and diffuse in the melanoma group and statistically significantly higher than that of the AML and nevus groups. There was no statistically significant difference between the nevus and AML groups. The Ki-67 proliferation index and HMB-45 staining pattern provided valuable indications for distinguishing between these 3 groups. The P16 antibody was limited in supporting the differential diagnosis. Our statistical model showed that a high mitosis count, central pagetoid spread, and PRAME positivity increased the probability of melanoma against an AML diagnosis. This study showed the advantages of evaluating the PRAME antibody together with morphological features and other immunohistochemical markers (Ki-67 and HMB-45) in the differential diagnosis of melanocytic lesions.

Immunohistochemistry of p53 surrogates TP53 mutation as an accurate predictor for early-relapse of surgically resected stage I-III lung adenocarcinoma

IntroductionTP53 is a strong tumor suppressor gene; its deactivation contributes to carcinogenesis and influences clinical outcomes. However, the prognostic influence of p53 deactivation on early relapse in patients with surgically resected non–small cell lung cancer remains unclear. Materials and methodsA cohort of 170 patients with primary stage I through III lung adenocarcinoma (LADC) and lung squamous cell carcinoma who underwent complete resection at Tokyo Medical and Dental University was screened for TP53 mutations using panel testing, and association studies between TP53 mutations and clinical data, including histology and postoperative recurrence, were performed. The association between TP53 mutations and postoperative recurrence was validated using data from 604 patients with MSK-IMPACT from The Cancer Genome Atlas. Additional immunohistochemistry for p53 was performed on some subsets of the Tokyo Medical and Dental University population. ResultsMutations in TP53 were recurrently observed (35.9%; 61 out of 170) in the Tokyo Medical and Dental University cohort. In the histology-stratified analysis, patients with LADC histology showed TP53 mutations that were associated with poor relapse-free survival (log-rank test; P = .020), whereas patients with lung squamous cell carcinoma histology showed TP53 mutations that were not (P = .99). The poor prognosis of TP53 mutation-positive LADCs was validated in The Cancer Genome Atlas-LADC cohort (log-rank test; P = .0065). Additional immunohistochemistry for p53 in patients with LADC histology in the Tokyo Medical and Dental University cohort showed a significant correlation between TP53 mutations and abnormal IHC pattern of p53 (Cramer's correlation coefficient V = 0.67). ConclusionsTP53 mutation is a potential marker for worse prognosis in surgically resected LADC; immunohistochemistry for p53 could be a surrogate method to identify patients with LADC with a worse prognosis.

Correlation study of functional magnetic resonance index and clinicopathological features of rectal cancer.

To investigate the correlation between DCE-MRI, R2*, IVIM, and clinicopathological features of rectal cancer. This was a prospective study, enrolling 42 patients with rectal cancer, 20 of whom underwent rectal mesorectal excision. Dynamic contrast-enhanced magnetic resonance imaging scanning was performed preoperatively in all patients, and additional preoperative scanning of R2* imaging and intravoxel incoherent motion was performed in those who underwent surgery. Artificially delineate the ROI around the tumor. Functional magnetic resonance index parameters Ktrans, Ve, R2*, D, D*, and f were estimated by computer software to analyze postoperative pathological reports of patients undergoing total mesenteric resection. Correlation and significance analyses of imaging metrics and pathologic features were performed by GraphPad Prism 9 to assess statistical significance. DEC-MRI, R2*, and IVIM have certain application values in the distance from the lower margin of the tumor to the anorectal ring, imaging T stage and N stage, tumor markers CEA and CA199, immunohistochemical indexes Ki-76 and P53, lymph node cancer metastasis, and rectal fascia status (P < 0.05). DEC-MRI, R2*, and IVIM provide reliable quantitative parameters for preoperative clinicopathological evaluation of patients with rectal cancer.

Ancillary immunohistochemical and molecular testing in the classification of cutaneous sweat gland/duct neoplasms: A validation study with emphasis on histomorphologic correlation and pathological diagnosis

Sweat gland neoplasms represent a challenging area of dermatopathology, as they are relatively uncommon and often histopathologically complex. Recent studies have uncovered distinct immunohistochemical and molecular profiles in several sweat gland neoplasms, including digital papillary adenocarcinoma (DPA), papillary eccrine adenoma/tubular apocrine adenoma (PEA/TAA), poroid family tumors (PFT)/porocarcinoma, and clear cell hidradenoma (CCH)/clear cell hidradenocarcinoma (CCHCa). To further evaluate the diagnostic utility of ancillary studies in various sweat gland neoplasms, we performed an independent validation study in a cohort of patients with acral and non-acral tumors (9 DPA, 8 PEA/TAA, 13 PFT, 5 porocarcinoma, 23 CCH, 7 CCHCa, 6 sweat gland carcinoma not otherwise specified). p63 immunohistochemistry (IHC) demonstrated a myoepithelial pattern in 8/8 DPA and 4 of 4 tested PEA/TAA cases, and showed a ductal pattern in all tested PFT/porocarcinoma and CCH/CCHCa cases (42/42). All PEA/TAA (8/8) cases were positive for BRAF V600E IHC. 5 of 12 tested PFT and 5/5 porocarcinoma cases showed either positive staining with NUT IHC or harbored YAP1::NUTM1 fusion gene by RNA sequencing. MAML2 fluorescence in situ hybridization (FISH) was positive in all CCH and CCHCa cases (23/23 and 7/7, respectively). Our results further support the usefulness of appropriate ancillary studies in precise classification of sweat gland tumors, which may be routinely applied in diagnostic pathology practice when morphologic evaluation is in doubt.

Molecular classification of metastatic and recurrent endometrial endometrioid carcinoma: prognostic relevance among low- and high-stage tumours.

Molecular classification according to The Cancer Genome Atlas (TCGA) improves endometrial endometrioid carcinoma (EEC) prognostication and has specific treatment implications; however, original data were skewed towards low-grade and low-stage tumours. Herein, we molecularly classify EECs metastatic at the time of diagnosis or with subsequently documented recurrent/metastatic disease to examine correlation with clinical outcomes. TCGA categories include POLE-mutated, microsatellite instability (MSI), p53 abnormal (p53 abnl) and no specific molecular profile (NSMP). POLE targeted sequencing at exons 9, 11, 13 and 14 and immunohistochemistry (IHC) for PMS2, MSH6 and p53 were performed to establish molecular classification. The distribution in our cohort of 141 EECs was similar to that generally reported in EEC, with nine POLE-mutated (6%), 45 MSI (32%), 16 p53 abnl (11%) and 71 NSMP (50%), with similar distributions between low- and high-stage cohorts. We demonstrate that when stratified by molecular subtype, disease-specific survival from the time of high-stage (stages III-IV) presentation or time of recurrence in low-stage (stages I-II) disease among metastatic and/or recurrent EEC is strongly associated with TCGA classification (high-stage P = 0.02, low-stage P = 0.017). Discordant molecular classification between primary and metastatic/recurrent tumours occurred in four of 105 (3.8%) patients, two related to PMS2/MSH6 IHC and two related to p53 IHC. We demonstrate that molecular classification is prognostically relevant not only at the time of diagnosis, but also at the time of recurrence and in the metastatic setting. Rare subclonal alterations occur and suggest a role for confirming TCGA classification in recurrent/metastatic tumours.

Advances in human papillomavirusdetection and molecular understanding in head and neck cancers: Implications for clinical management.

Head and neck cancers (HNCs), primarily head and neck squamous cell carcinoma (HNSCC), are associated with high-risk human papillomavirus (HR HPV), notably HPV16 and HPV18. HPV status guides treatment and predicts outcomes, with distinct molecular pathways in HPV-driven HNSCC influencing survival rates. HNC incidence is rising globally, with regional variations reflecting diverse risk factors, including tobacco, alcohol, and HPV infection. Oropharyngeal cancers attributed to HPV have significantly increased, particularly in regions like the United States. The HPV16 genome, characterized by oncoproteins E6 and E7, disrupts crucial cell cycle regulators, including tumor protein p53 (TP53) and retinoblastoma (Rb), contributing to HNSCC pathogenesis. P16 immunohistochemistry (IHC) is a reliable surrogate marker for HPV16 positivity, while in situ hybridizationand polymerase chain reaction (PCR) techniques, notably reverse transcription-quantitative PCR (RT-qPCR), offer sensitive HPV detection. Liquid-based RT-qPCR, especially in saliva, shows promise for noninvasive HPV detection, offering simplicity, cost-effectiveness, and patient compliance. These molecular advancements enhance diagnostic accuracy, guide treatment decisions, and improve patient outcomes in HNC management. In conclusion, advances in HPV detection and molecular understanding have significant clinical management implications. Integrating these advancements into routine practice could ultimately improve patient outcomes.

Neoadjuvant adebrelimab plus dalpiciclib in HPV-negative locally advanced head and neck squamous cell carcinoma: A phase II clinical trial.

TPS6129 Background: The efficacy and safety of neoadjuvant immunotherapy (NAI) for treating resectable locally advanced head and neck squamous cell carcinoma (LAHNSCC) remain uncertain, and the comprehensive protocol of NAI needs further explored. The tumor suppressor gene CDKN2A plays a pivotal role in cell cycle regulation by modulating cyclin-dependent kinase (CDK) activity. Mutations in CDKN2A lead to continuous activation of CDK4/6, resulting in uncontrolled cell proliferation and tumor growth. Approximately 35.7% of HNSCC patients exhibit CDKN2A mutations, with the incidence rising to 58% among HPV-negative LAHNSCC patients. Studies have shown that combining immunotherapy with a CDK4/6 inhibitor produces a synergistic anti-tumor effect. This study aims to assess the efficacy and safety of combining anti-PD-L1 (adebrelimab) with a CDK4/6 inhibitor (dalpiciclib) as NAI in resectable LAHNSCC patients. Methods: This open-label, single-arm, prospective phase II trial will enroll LAHNSCC patients eligible for surgery. Inclusion criteria include: being 18 to 75 years old at study entry; pathologically confirmed HPV-negative HNSCC (oral, laryngeal, hypopharyngeal, and HPV-negative oropharyngeal carcinoma), determined via p16 immunohistochemistry or HPV DNA tests; with CDKN2A mutation; resectable LAHNSCC, staged III-IVB according to the UICC/AJCC 8th edition TNM system; an ECOG Performance Status score of 0 or 1; no prior relevant anti-tumor treatments; intent for curative treatment; and adequate organ function. Key exclusion criteria are active autoimmune diseases, use of immunosuppressive drugs, or systemic corticosteroids. Eligible patients receive 3 cycles of adebrelimab (1200 mg intravenously every 3 weeks, Day 1, 22 and 43) and 2 cycles of dalpiciclib (150 mg, po, every 4 weeks, day 1-21 and 29-49) before surgery. Dose adjustments are allowed based on toxicity. Surgery will follow 2-4 weeks post-NAI, with subsequent adjuvant radiotherapy or chemoradiotherapy based on risk factors after surgery. The primary endpoints are 1-year disease-free survival (defined as the time from surgical resection to local recurrence) and major pathological response (MPR, defined as ≤10% residual viable tumor cells), with secondary endpoints focusing on safety and predictive biomarkers. Clinical trial information: NCT06199271 .

Redefining aberrant P53 expression of gastric cancer and its distinct clinical significance among molecular-histologic subtypes

BackgroundNumerous studies have demonstrated a correlation between p53 overexpression and diminished survival in gastric cancer patients. However, conflicting findings exist, and we hypothesize that these discrepancies arise from the cancer's complexity and heterogeneity, coupled with a lack of consensus on aberrant p53 expression. MethodsWe enrolled a cohort of 187 patients with surgically resected gastric cancer. Patient categorization was based on Epstein–Barr virus (EBV), microsatellite instability (MSI), and Lauren classification (intestinal, diffuse and mixed). Utilizing an incremental algorithm, we evaluated p53 immunohistochemical (IHC) patterns in all 187 cases, while next-generation sequencing was successfully performed on 152 cases to identify TP53 mutations (mutTP53). ResultsMutTP53 was identified in 32 % of the 152 cases, comprising 36 missense, 5 nonsense, and 7 frameshift alterations. Missense mutations predominantly correlated with p53 overexpression, while nonsense and frameshifting alterations related to null expression. Trial calculations indicated that null expression and a p53 IHC cutoff at >40 % offered the best prediction of mutTP53 (kappa coefficient, 0.427), with the highest agreement (0.524) observed in diffuse type and the lowest (0.269) in intestinal type. Null expression and a p53 IHC cutoff at >10 %, but not mutTP53 per se, provided the optimal prediction of survival outcome (p = 0.043), particularly in diffuse type (p = 0.044). Multivariate analysis showed that aberrant p53 IHC expression was not an independent prognostic factor. ConclusionsP53 IHC patterns are predictive biomarkers for mutTP53 and gastric cancer outcomes, where a prerequisite involves a nuanced approach considering cutoff values and molecular-histologic subtyping.

Stromal p16 and SATB2 Expression Does Not Distinguish Atypical Polypoid Adenomyoma (APA) From its Benign Mimics.

Atypical polypoid adenomyoma (APA) is a polypoid biphasic lesion of low malignant potential that arises in the lower uterine segment and uterine corpus. The diagnosis of APA is often challenging on biopsy and curettage specimens, and both benign and malignant processes need to be considered in the differential. Stromal expression of p16 and SATB2 have recently been shown to distinguish APA from myoinvasive endometrioid carcinoma. The authors hypothesized that p16 and SATB2 immunohistochemistry could also aid in the distinction of APA from benign adenomyomatous polyp and endometrioid adenomyoma. The study comprised 10 APAs, 7 adenomyomatous polyps, 11 endometrioid adenomyomas, and 10 myoinvasive endometrioid carcinomas. The majority of APAs showed moderate to strong, diffuse p16 and stromal expression. However, most adenomyomatous polyps and endometrioid adenomyomas also exhibited moderate to strong, focal to diffuse p16 stromal expression. SATB2 showed weak to moderate, focal to diffuse expression in the majority of APAs, adenomyomatous polyps and endometrioid adenomyomas. In contrast, p16 and SATB2 were negative to weak and focal in 90% of myoinvasive endometrioid carcinomas. Our findings demonstrate that p16 and SATB2 may be helpful in the differential diagnosis of myoinvasive endometrioid carcinoma and APA while not useful in separating APA from adenomyomatous polyp and endometrioid adenomyoma.

P63 Expressing Adenocarcinoma of The Prostate Gland, A Rare Neoplasm Which Tends to Pose Diagnostic Dilemma Sometimes: Review and Update

It has been documented that prostate cancer is the world's leading cause of cancer and also the second commonest cancer in men which does tend to pose challenges in its diagnosis. It has been iterated that immunohistochemistry studies utilising tumour markers like high molecular weight cytokeratin, p63 aid in the diagnosis of prostate cancer. It has been known for some time that the absence of immunohistochemistry staining of prostate lesion for p63 and high molecular weight cytokeratin and presence of p504s in the biopsies indicate malignant lesions. Nevertheless, it had also been pointed out as well as documented that some rare cases of adenocarcinoma of prostate variants do demonstrate evidence of the tumour cells exhibiting p63 immunohistochemistry staining and this does pose a diagnostic dilemma that may make the unfamiliar pathologist mis-diagnose such a malignant tumour as a benign prostate lesion. p63-positive adenocarcinoma of the prostate gland is a major diagnostic pitfall. There is a danger of interpreting malignant glands as benign and arriving at a false-negative diagnosis. This can be prevented by the understanding of the pattern of immunohistochemistry staining expression related to this variant of prostate cancer. The major points that favour the diagnosis of carcinoma in these cases include: non-basal p63 staining and negative HWMCK and positive p504s staining. The biological behaviour of this particular rare variant of prostatic carcinoma is not certain and requires to be studied further into more detail. Considering the rarity of p63 expressing prostate cancers and the fact that most clinicians including pathologists, urologists, and oncologists would not have encountered a case of p63 expressing prostate cancer before in order to update all clinicians regarding this rare tumour, the ensuing article has been extensively written and divided into two parts: (A) Overview which has discussed general overview aspects of p63 expressing neoplasms and (B) Miscellaneous Narrations and Discussions from Some Case Reports, Case Series, and Studies Related to Primary p63 Expressing Adenocarcinomas of the Prostate Gland. A high-index of suspicion as well as knowledge of the histopathology examination features as well as immunohistochemistry examination features of this rare tumour is required from all clinicians. Knowledge of the treatment options, biological behaviour as well as outcome following treatment of the tumour has been extensively discussed as updating information. The update has clearly pointed out that further studies are required to determine the role of p63 overexpression in prognostication.

P16 Expression in Multinucleated Stromal Cells of Fibroepithelial Polyps of the Anus (FEPA): A Comprehensive Review and Our Experience

Fibroepithelial polyps of the anus (FEPA) are a common benign polypoid proliferation of the stroma covered by squamous epithelium. They are also an often-overlooked part of pathological practice. Currently, immunohistochemistry (IHC) for p16 is the only recommended test for anal intraepithelial neoplasia, but the expression of p16 in stromal multinucleated atypical cells in FEPA has not been described. We aimed to evaluate the expression of p16 in stromal multinucleated atypical cells in FEPA and its role as a diagnostic biomarker to determine the origin of the atypical multinucleated cells in the stroma of FEPA and to rule out the possibility of a neoplastic process. Therefore, we researched a series of 15 FEPA in middle-aged patients histologically and by IHC. Examination of the subepithelial connective tissue from the FEPA showed bizarre, multinucleated cells, while their causal relationship with human papillomavirus (HPV) infection was rejected. In all cases, these cells showed mild to moderate atypical nuclear features and positive expression for p16, while the overlying squamous epithelium was negative. We concluded that FEPA are benign lesions in the stroma where mononuclear and multinucleated (sometimes atypical) cells showing fibroblastic and myofibroblastic differentiation can be found. Nevertheless, we believe that these cells have a practical diagnostic significance, although sometimes the presence of giant cells is difficult to establish, especially in the inflammatory context. The histological similarity between FEPA and normal anal mucosa supports the hypothesis that FEPA may represent the reactive hyperplasia of subepithelial fibrous connective tissue of the anal mucosa.

Abstract A025: Integrating genomic alterations and histopathological features for enhanced risk stratification in non-muscle invasive bladder cancer

Abstract Urothelial carcinoma is the most prevalent type of bladder cancer, where non-muscle invasive bladder cancer (NMIBC) accounts for about 75% of the initial diagnosis. Recognizing the limitations of current WHO04/16 grading and TNM staging systems, this study investigates genomic alterations, mitotic activity index (MAI) and immunohistochemical (IHC) markers CK20, p53, and CD25 to identify better prognostic biomarkers in NMIBC. In this retrospective population-based study of NMIBC patients (n=287), a targeted next-generation sequencing (NGS) panel analysis was performed using Oncomine™ Focus Assay on Ion GeneStudio S5 platform to identify genomic changes, including single nucleotide variations (SNVs) and copy number variations (CNVs) across 52 genes. The results revealed that the most frequent gene variants were identified in FGFR3 (n=183, 45%) and PIK3CA (n=98, 24%), while AKT1 (n=39, 20%), ERBB2 (n=24, 12%), MYCN (n=23, 12%) and CCND1 (n=22, 11%) were among the most amplified genes. Distinct genetic associations were observed among Ta, T1, low-grade (LG), and high-grade (HG) tumors. Ta tumors were significantly associated with FGFR3 and PIK3CA mutations, while T1 tumors were linked to ERBB2 mutations (p&amp;lt;0.001). Additionally, LG tumors were enriched with FGFR3 mutations, while HG tumors were significantly associated with FGFR1, CCND1, and ERBB2 mutations (p&amp;lt;0.001). In the analysis of tumor recurrence, patients with FGFR3 mutations had significantly shorter recurrence-free survival (RFS) (p=0.033). Analysis of stage progression revealed a significant association between FGFR3 mutations and improved PFS (p&amp;lt;0.001), while MYC, ERBB2 (p&amp;lt;0.001), and MYCN (p=0.011) were linked to shorter PFS. In gene set enrichment analysis, gene sets like PIK3CA and ERBB2 (p=0.003), and PIK3CA and MYC (p=0.005), were inversely associated with progression-free survival (PFS). In the multivariate Cox regression analysis, MAI was the strongest predictor for PFS (p&amp;lt;0.001). The study emphasizes the potential of combining genomic alterations with histopathological features for enhanced risk stratification in NMIBC patients. Citation Format: Melinda Lillesand, Vebjørn Kvikstad, Einar Gudlaugsson, Ivar Skaland, Aida Slewa Johannessen, Almaz Nigatu Tesfahun, Sigmund Vegard Sperstad, Emiel A.M. Janssen, Marie Austdal. Integrating genomic alterations and histopathological features for enhanced risk stratification in non-muscle invasive bladder cancer [abstract]. In: Proceedings of the AACR Special Conference on Bladder Cancer: Transforming the Field; 2024 May 17-20; Charlotte, NC. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(10_Suppl):Abstract nr A025.