Comprehensive evaluation of the relationship between biomarker profiles and neoadjuvant chemotherapy outcomes for breast cancer patients.

BACKGROUND: Accurately predicting the response to neoadjuvant chemotherapy (NAC) in breast cancer patients is crucial for guiding treatment strategies and enhancing clinical outcomes. Current studies have primarily focused on a limited set of biomarkers. More importantly, the results of many studies are in conflict. To address this, we conducted a comprehensive evaluation of the predictive value of a diverse range of clinically available molecular biomarkers in breast cancer, including HER2, ER, PR, TOPO II, EGFR, Ki67, CK5/6, AR, and p53. Additionally, we assessed changes in these biomarkers after NAC administration. METHODS: Our study involved 189 patients with invasive breast cancer who underwent NAC at our institute. We examined biomarker profiles in core-needle biopsies taken before NAC and in surgical specimens obtained after NAC. We examined the association between these biomarkers and NAC outcomes, focusing on two main aspects: the rate of pathological complete response (pCR) and the reduction in tumor size. We used Chi-square and Mann-Whitney U tests to compare biomarker status changes between pCR and non-pCR patients. Linear regression analysis was employed to evaluate the relationship between biomarker status and tumor shrinkage rate. Additionally, we compared the expression status of these biomarkers before and after NAC using Chi-square and Wilcoxon signed-rank tests. RESULTS AND CONCLUSIONS: Our results demonstrated significant differences in the expression levels of HER2, ER, PR, TOPO II, EGFR, and Ki67 between pCR and non-pCR patients, underscoring their potential as predictive markers for NAC outcomes. Importantly, our results have shed light on the contentious issue surrounding TOPO II in NAC outcome prediction. We have provided evidence that establishes a significantly positive association between TOPO II expression level and the pCR rate. Notably, tumor size was identified as a relevant predictive factor for achieving pCR. Regarding biomarker profiles, only Ki67 levels and TOPO II status exhibited changes following NAC, resolving previous controversies. While the ER and PR status remained unchanged, their expression values exhibited a slight but significant decrease post-NAC. Our results provide clarity and insights into the value and potential of using these biomarkers to predict NAC responses and prognosis in breast cancer patients.

Predictive value of cyst/tumor volume ratio of pituitary adenoma for tumor cell proliferation.

BACKGROUND: MRI has been widely used to predict the preoperative proliferative potential of pituitary adenoma (PA). However, the relationship between the cyst/tumor volume ratio (C/T ratio) and the proliferative potential of PA has not been reported. Herein, we determined the predictive value of the C/T ratio of PA for tumor cell proliferation. METHODS: The clinical data of 72 patients with PA and cystic change on MRI were retrospectively analyzed. PA volume, cyst volume, and C/T ratio were calculated. The corresponding intraoperative specimens were collected. Immunohistochemistry and hematoxylin-eosin staining were performed to evaluate the Ki67 index and nuclear atypia. Patients were categorized according to the Ki67 index (< 3% and ≥ 3%) and nuclear atypia (absence and presence). Univariate and multivariate analyses were used to identify the significant predictors of the Ki67 index and nuclear atypia. The receiver operating characteristic curve assessed the prediction ability of the significant predictors. RESULTS: Larger tumor volumes, smaller cyst volumes, and lower C/T ratios were found in patients with higher Ki67 indexes and those with nuclear atypia (P < 0.05). C/T ratio was an independent predictor of the Ki67 index (odds ratio = 0.010, 95% confidence interval = 0.000-0.462) and nuclear atypia (odds ratio = 0.010, 95% confidence interval = 0.000-0.250). The predictive value of the C/T ratio did not differ significantly from that of tumor volume (P > 0.05) but was better than that of cyst volume (P < 0.05). The area under the curve of the C/T ratio for predicting the Ki67 index and nuclear atypia was larger than that for predicting cyst volume and tumor volume. CONCLUSIONS: C/T ratios can be used to predict PA tumor proliferation preoperatively. Our findings may facilitate the selection of surgery timing and the efficacy evaluation of surgery.

Correlation between high-risk HPV infection and p16/Ki-67 abnormalities in Pap samples in a South Eastern Europe cohort.

Cervical cancer (CC) is the fourth most common cause of cancer-related deaths amongst women worldwide. CC represents a major global healthcare issue, and Romania ranks the worst in mortality rates amongst EU countries. However, the early detection of CC can be lifesaving. To understand the testing process undergone by women in Romania, we performed a retrospective study, and investigated a cohort of 83 785 cervical cases from Romanian women aged 15-70, obtained in private-based opportunistic screening. We examined the correlation between Pap smear results, human papilloma virus (HPV) genotyping, and the expression of cell cycle markers p16 and Ki-67. Analysis of Pap results revealed approximately 10% abnormal cases, of which high-grade squamous intraepithelial lesions constituted 4.9%. HPV genotyping of 12 185 cases with available Pap results unveiled a range of high-risk HPV (hrHPV) types associated with cervical abnormalities. Notably, 26% of hrHPV-positive cases showed no observable abnormalities. In a subset of cases with abnormal Pap and a type of hrHPV, P16/Ki-67 double-staining was also positive. This study suggests the importance of an integrated diagnostic algorithm that should consider the HPV genotype, Pap smear, and p16/Ki-67 staining. This algorithm should enhance the CC screening accuracy and its management strategies, particularly in those regions with a high disease burden, such as Romania.

Recommendations for Use of p16/Ki67 Dual Stain for Management of Individuals Testing Positive for Human Papillomavirus.

OBJECTIVES: The Enduring Consensus Cervical Cancer Screening and Management Guidelines Committee developed recommendations for dual stain (DS) testing with CINtec PLUS Cytology for use of DS to triage high-risk human papillomavirus (HPV)-positive results. METHODS: Risks of cervical intraepithelial neoplasia grade 3 or worse were calculated according to DS results among individuals testing HPV-positive using data from the Kaiser Permanente Northern California cohort and the STudying Risk to Improve DisparitiES study in Mississippi. Management recommendations were based on clinical action thresholds developed for the 2019 American Society for Colposcopy and Cervical Pathology Risk-Based Management Consensus Guidelines. Resource usage metrics were calculated to support decision-making. Risk estimates in relation to clinical action thresholds were reviewed and used as the basis for draft recommendations. After an open comment period, recommendations were finalized and ratified through a vote by the Consensus Stakeholder Group. RESULTS: For triage of positive HPV results from screening with primary HPV testing (with or without genotyping) or with cytology cotesting, colposcopy is recommended for individuals testing DS-positive. One-year follow-up with HPV-based testing is recommended for individuals testing DS-negative, except for HPV16- and HPV18-positive results, or high-grade cytology in cotesting, where immediate colposcopy referral is recommended. Risk estimates were similar between the Kaiser Permanente Northern California and STudying Risk to Improve DisparitiES populations. In general, resource usage metrics suggest that compared with cytology, DS requires fewer colposcopies and detects cervical intraepithelial neoplasia grade 3 or worse earlier. CONCLUSIONS: Dual stain testing with CINtec PLUS Cytology is acceptable for triage of HPV-positive test results. Risk estimates are portable across different populations.

Immunohistochemical double nuclear staining for cell-specific automated quantification of the proliferation index - A promising diagnostic aid for melanocytic lesions.

AIMS: Pathologists often use immunohistochemical staining of the proliferation marker Ki67 in their diagnostic assessment of melanocytic lesions. However, the interpretation of Ki67 can be challenging. We propose a new workflow to improve the diagnostic utility of the Ki67-index. In this workflow, Ki67 is combined with the melanocytic tumour-cell marker SOX10 in a Ki67/SOX10 double nuclear stain. The Ki67-index is then quantified automatically using digital image analysis (DIA). The aim of this study was to optimise and test three different multiplexing methods for Ki67/SOX10 double nuclear staining. METHODS: Multiplex immunofluorescence (mIF), multiplex immunohistochemistry (mIHC), and multiplexed immunohistochemical consecutive staining on single slide (MICSSS) were optimised for Ki67/SOX10 double nuclear staining. DIA applications were designed for automated quantification of the Ki67-index. The methods were tested on a pilot case-control cohort of benign and malignant melanocytic lesions (n = 23). RESULTS: Using the Ki67/SOX10 double nuclear stain, malignant melanocytic lesions could be completely distinguished from benign lesions by the Ki67-index. The Ki67-index cut-offs were 1.8% (mIF) and 1.5% (mIHC and MICSSS). The AUC of the automatically quantified Ki67-index based on double nuclear staining was 1.0 (95% CI: 1.0;1.0), whereas the AUC of conventional Ki67 single-stains was 0.87 (95% CI: 0.71;1.00). CONCLUSIONS: The novel Ki67/SOX10 double nuclear stain highly improved the diagnostic precision of Ki67 interpretation. Both mIHC and mIF were useful methods for Ki67/SOX10 double nuclear staining, whereas the MICSSS method had challenges in the current setting. The Ki67/SOX10 double nuclear stain shows potential as a valuable diagnostic aid for melanocytic lesions.

Ki-67 Proliferation Index Is Associated With Tumor Grade and Survival in Pleural Epithelioid Mesotheliomas.

Pleural epithelioid mesothelioma (PEM) is divided into low and high grades based on nuclear atypia, mitoses, and necrosis in the tumor. Assessing mitoses and nuclear atypia tend to be labor-intensive with limited reproducibility. Ki-67 proliferation index was shown to be a prognostic factor in PEM, but its performance has not been directly correlated with tumor grade or mitotic score. This study evaluated the potential of Ki-67 index as a surrogate of tumor grade. We also compared the predictability of mitoses and Ki-67 index for overall survival (OS). Ninety-six PEM samples from 85 patients were identified from the surgical pathology file during 2000-2021 at our institution, and all glass slides were reviewed by 2 pulmonary pathologists to confirm the diagnosis and assign the tumor grade. Digital image analysis (DIA) was done for Ki-67 index. The agreement on tumor grading between 2 reviewers was moderate (kappa value = 0.47). The correlation between mitotic count (average count by 2 reviewers) and Ki-67 index was 0.65. The areas under the curve for predicting tumor grade by mitotic score and Ki-67 index were 0.84 and 0.74 (reviewer 1) and 0.85 and 0.81 (reviewer 2), respectively. High Ki-67 index and mitoses were significantly associated with poor OS ( P =0.03 and 0.0005, using 30% and 10/2 mm 2 as cutoffs, respectively). In conclusion, Ki-67 index by DIA was associated with tumor grade as well as mitotic count, and its predictability for OS was comparable to that of mitotic score, thus being a potential surrogate for tumor grade.

[The expression of Plakoglobin in residual cancer after neoadjuvant chemotherapy for breast cancer and its prognostic impact on patients].

Objective: To investigate the relationship between the expression levels of Plakoglobin protein in residual lesions after neoadjuvant chemotherapy (NAC) and the prognosis of breast cancer patients. Methods: Clinical and pathological data from 174 breast cancer patients who underwent surgery after receiving NAC at the Cancer Hospital of Chinese Academy of Medical Sciences from January 2009 to December 2017 were collected. The expression level of Plakoglobin in residual cancer lesions was evaluated by immunohistochemistry. The correlation between Plakoglobin expression level and clinicopathological features was analyzed. Survival analysis was performed using the Kaplan-Meier method, and Cox proportional hazard regression models were used for factor analysis. Results: Among the 174 patients, 140 had low expression of Plakoglobin, and 34 had high expression. The median disease-free survival (DFS) and overall survival (OS) in the Plakoglobin low expression group were 59.46 and 71.68 months, respectively, both of which were higher than those in the high expression group (36.58 and 47.26 months, respectively, both P<0.05). Univariate analysis showed that Plakoglobin expression, pathological N stage, lymphovascular invasion status, histological grade, Ki-67, and molecular subtypes were associated with OS (all P<0.05), while pathological N stage, histological grade, and Ki-67 were associated with DFS (all P<0.05). Multivariate analysis revealed that Plakoglobin expression (HR=2.438, 95% CI: 1.256-4.735, P=0.008) was an independent predictor for OS, and Ki-67 (HR=2.228, 95% CI: 1.316-3.773, P=0.003) was an independent predictor for DFS. Conclusion: In breast cancer patients with residual lesions after NAC, those with low Plakoglobin expression have relatively longer OS and Plakoglobin is an independent prognostic factor for OS.

Validation of an on-chip p16ink4a/Ki-67 dual immunostaining cervical cytology system using microfluidic device technology.

More specific screening systems for cervical cancer may become necessary as the human papillomavirus (HPV) vaccine becomes more widespread. Although p16/Ki-67 dual-staining cytology has several advantages, it requires advanced diagnostic skills. Here, we developed an automated on-chip immunostaining method using a microfluidic device. An electroactive microwell array (EMA) microfluidic device with patterned thin-film electrodes at the bottom of each microwell was used for single-cell capture by dielectrophoresis. Immunostaining and dual staining for p16/Ki-67 were performed on diagnosed liquid cytology samples using the EMA device. The numbers of p16/Ki-67 dual-stained cells captured by the EMA device were determined and compared among the cervical intraepithelial neoplasia (CIN) lesion samples. Seven normal, fifteen CIN grade 3, and seven CIN grade 2 samples were examined. The percentage of dual-positive cells was 18.6% in the CIN grade 2 samples and 23.6% in the CIN grade 3 samples. The percentages of dual-positive staining increased significantly as the severity of the cervical lesions increased. p16/Ki67 dual immunostaining using the EMA device is as sensitive as the conventional method of confirming the histopathological diagnosis of cervical samples. This system enables a quantified parallel analysis at the individual cell level.

Ki67 and breast cancer mortality in women with invasive breast cancer.

BACKGROUND: The percentage of cells staining positive for Ki67 is sometimes used for decision-making in patients with early invasive breast cancer (IBC). However, there is uncertainty regarding the most appropriate Ki67 cut points and the influence of interlaboratory measurement variability. We examined the relationship between breast cancer mortality and Ki67 both before and after accounting for interlaboratory variability and 8 patient and tumor characteristics. METHODS: A multicenter cohort study of women with early IBC diagnosed during 2009-2016 in more than 20 NHS hospitals in England and followed until December 31, 2020. RESULTS: Ki67 was strongly prognostic of breast cancer mortality in 8212 women with estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative early IBC (Ptrend < .001). This relationship remained strong after adjustment for patient and tumor characteristics (Ptrend < .001). Standardization for interlaboratory variability did little to alter these results. For women with Ki67 scores of 0%-5%, 6%-10%, 11%-19%, and 20%-29% the corresponding 8-year adjusted cumulative breast cancer mortality risks were 3.3% (95% confidence interval [CI] = 2.8% to 4.0%), 3.7% (95% CI = 3.0% to 4.4%), 3.4% (95% CI = 2.8% to 4.1%), and 3.4% (95% CI = 2.8% to 4.1%), whereas for women with Ki67 scores of 30%-39% and 40%-100%, these risks were higher, at 5.1% (95% CI = 4.3% to 6.2%) and 7.7% (95% CI = 6.6% to 9.1) (Ptrend < .001). Similar results were obtained when the adjusted analysis was repeated with omission of pathological information about tumor size and nodal involvement, which would not be available preoperatively for patients being considered for neoadjuvant therapy. CONCLUSION: Our findings confirm the prognostic value of Ki67 scores of 30% or more in women with ER-positive, HER2-negative early IBC, irrespective of interlaboratory variability. These results also suggest that Ki67 may be useful to aid decision-making in the neoadjuvant setting.

Blastoid and Pleomorphic Mantle Cell Lymphoma Demonstrate Distinct Clinicopathologic and Genetic Features.

The blastoid (B) and pleomorphic (P) variants of mantle cell lymphoma (MCL) are associated with aggressive clinical behavior. In this study, we collected 102 cases of B-MCL and P-MCL from untreated patients. We reviewed clinical data, analyzed morphologic features using an image analysis tool (ImageJ) and we assessed mutational and gene expression profiles. The chromatin pattern of lymphoma cells was assessed quantitatively by the pixel value. Cases of B-MCL showed a greater median pixel value with lower variation compared with P-MCL, indicating a homogeneously euchromatin-rich pattern in B-MCL. In addition, the Feret diameter of the nuclei was significantly smaller (median 6.92 vs. 8.49 µm per nucleus, P <0.001) and had a lesser degree of variation in B-MCL compared with P-MCL, indicating that B-MCL cells have smaller cells with a more monomorphic appearance. B-MCL showed a significantly higher median Ki-67 proliferation rate (60% vs. 40%, P =0.003), and affected patients had poorer overall survival compared with those with P-MCL (median overall survival: 3.1 vs. 8.8 y, respectively, P =0.038). NOTCH1 mutation was significantly more frequent in B-MCL compared with P-MCL (33% and 0%, respectively, P =0.004). Gene expression profiling showed 14 genes overexpressed in B-MCL cases and gene set enrichment assay for the overexpressed genes showed significant enrichment in the cell cycle and mitotic transition pathways. We also report a subset of MCL cases that has blastoid chromatin but a higher degree of pleomorphism in nuclear size and shape, designated here as hybrid MCL. Hybrid MCL cases had a similar Ki-67 proliferation rate, mutation profile, and clinical outcome to B-MCL and distinct from P-MCL. In summary, these data suggest biological differences between B-MCL and P-MCL cases justifying their separate designation when possible.

Exploration of Digital Image Analysis for Ki67 Quantification in the Grading of Medullary Thyroid Carcinoma: A Pilot Study with 85 Cases.

BACKGROUND: Although uncommon, medullary thyroid carcinoma (MTC) accounts for a significant proportion of thyroid cancer deaths. Recent studies have validated the two-tier International Medullary Thyroid Carcinoma Grading System (IMTCGS) to predict clinical outcomes. A 5% Ki67 proliferative index (Ki67PI) cut-off separates low-grade from high-grade MTC. In this study, we compared digital image analysis (DIA) to manual counting (MC) for determining the Ki67PI in a MTC cohort, and explored the challenges encountered. METHODS: Available slides from 85 MTCs were reviewed by two pathologists. The Ki67PI was documented by immunohistochemistry for each case, scanned with the Aperio® slide scanner at 40× magnification, and quantified using the QuPath® DIA platform. The same hotspots were screenshot, printed in color, and blindly counted. For each case, over 500 MTC cells were counted. Each MTC was graded using IMTCGS criteria. RESULTS: In our MTC cohort (n = 85), 84.7 and 15.3% were low- and high-grade with the IMTCGS. In the entire cohort, QuPath® DIA performed well (R2 = 0.9891) but appeared to undercall compared to MC. QuPath® performed better in high-grade cases (R2 = 0.99) compared to low-grade cases (R2 = 0.7071). Overall, Ki67PI determined with either MC or DIA did not affect IMTCGS grade. Encountered DIA challenges include optimizing cell detection, overlapping nuclei, and tissue artifacts. Encountered MC challenges include background staining, morphologic overlap with normal elements, and counting time. CONCLUSION: Our study highlights the utility of DIA in quantifying Ki67PI for MTC and can serve as an adjunct for grading in conjunction with the other criteria of mitotic activity and necrosis.

A Clinicopathological Analysis of Asian Patients with Adrenocortical Carcinoma: A Single-Center Experience.

BACKGROUND: There is limited information regarding the immunohistochemistry stain and its prognostic role in adrenocortical carcinoma (ACC), and few studies focus on Asian patients. Our study aims to identify the correlation between immunohistochemistry staining and the prognosis of ACC in Asian patients. METHODS: We searched the database of a single center in Taiwan for cases with a pathological diagnosis of ACC in the past 25 years. We collected patient data on age, sex, initial presentation, staging, metastatic site, and survival duration. Immunohistochemical studies using antibodies to CDK4, ATRX, beta-catenin, Ki-67, SSTR2, and p53 were performed. Survival analysis was performed using the log-rank test, the Cox proportional hazards model and bootstrapping with 5000 samplings. RESULTS: Fourteen patients were identified, and the median age was 49.5 (range 1-70) years. There were eight male and six female patients. Four patients presented with Cushing's syndrome, and half were diagnosed with stage IV ACC at presentation. Only three patients survived (21%). The median survival time was 15.5 (range 0.67-244) months. SSTR2 expression score > 50 (log-rank test: p = 0.009) and Ki-67 > 50% (log-rank test: p = 0.017) were associated with mortality. However, after adjusting for stage, the bootstrapping analysis demonstrated that Ki-67 [B 2.04, p = 0.004], Beta-catenin [B 2.19, p = 0.009], ATRX [B 1.48, p = 0.026], P53 [B 1.58, p = 0.027], SSTR2 [B 1.58, p = 0.015] and SSTR2 expression score [B 0.03, p < 0.001] were all significantly associated with mortality. CONCLUSIONS: After adjusting for stage, Ki-67 > 50%, Beta-catenin, ATRX, P53, SSTR2 and SSTR2 expression score > 50 were associated with mortality in Asian patients with ACC.

Triaging HPV-Positive Cervical Samples with p16 and Ki-67 Dual Stained Cytology within an Organized Screening Program-A Prospective Observational Study from Western Norway.

The implementation of high-risk human papillomavirus testing (hrHPV testing) as a screening method in substitute for cytology has evoked the need for more sensitive and less objective tests for the triage of HPV-positive women. In a cohort of 1763 HPV-positive women, the potential of immunocytochemical p16 and Ki-67 dual staining as compared to cytology, alone or in combination with HPV partial genotyping, was tested for triage of women attending a cervical cancer screening program. Performance was measured using sensitivity, specificity, and positive and negative predictive values. Comparisons were assessed using logistic regression models and the McNemar test. Dual staining was evaluated in a prospectively collected study cohort of 1763 HPV-screened women. For triage of CIN2+ and CIN3+, NPV and sensitivity, 91.8% and 94.2% versus 87.9% and 89.7%, respectively, were significantly higher using dual staining together with HPV 16/18 positive, as compared to cytology (p < 0.001). The specificities, however, were lower for dual staining as compared to cytology. Conclusions: Dual staining is safer for decision-making regarding HPV-positive women's need for follow-up with colposcopy and biopsy, as compared to cytology.

Using Intratumor Heterogeneity of Immunohistochemistry Biomarkers to Classify Laryngeal and Hypopharyngeal Tumors Based on Histologic Features.

Haralick texture features are used to quantify the spatial distribution of signal intensities within an image. In this study, the heterogeneity of proliferation (Ki-67 expression) and immune cells (CD45 expression) within tumors was quantified and used to classify histologic characteristics of larynx and hypopharynx carcinomas. Of 21 laryngectomy specimens, 74 whole-mount tumor slides were scored on histologic characteristics. Ki-67 and CD45 immunohistochemistry was performed, and all sections were digitized. The tumor area was annotated in QuPath. Haralick features independent of the diaminobenzidine intensity were extracted from the isolated diaminobenzidine signal to quantify intratumor heterogeneity. Haralick features from both Ki-67 and CD45 were used as input for a principal component analysis. A linear support vector machine was fitted to the first 4 principal components for classification and validated with a leave-one-patient-out cross-validation method. Significant differences in individual Haralick features were found between cohesive and noncohesive tumors for CD45 (angular second motion: P =.03, inverse difference moment: P =.009, and entropy: P =.02) and between the larynx and hypopharynx tumors for both CD45 (angular second motion: P =.03, inverse difference moment: P =.007, and entropy: P =.005) and Ki-67 (correlation: P =.003). Therefore, these features were used for classification. The linear classifier resulted in a classification accuracy of 85% for site of origin and 81% for growth pattern. A leave-one-patient-out cross-validation resulted in an error rate of 0.27 and 0.35 for both classifiers, respectively. In conclusion, we show a method to quantify intratumor heterogeneity of immunohistochemistry biomarkers using Haralick features. This study also shows the feasibility of using these features to classify tumors by histologic characteristics. The classifiers created in this study are a proof of concept because more data are needed to create robust classifiers, but the method shows potential for automated tumor classification.

Noninferiority of Artificial Intelligence-Assisted Analysis of Ki-67 and Estrogen/Progesterone Receptor in Breast Cancer Routine Diagnostics.

Image analysis assistance with artificial intelligence (AI) has become one of the great promises over recent years in pathology, with many scientific studies being published each year. Nonetheless, and perhaps surprisingly, only few image AI systems are already in routine clinical use. A major reason for this is the missing validation of the robustness of many AI systems: beyond a narrow context, the large variability in digital images due to differences in preanalytical laboratory procedures, staining procedures, and scanners can be challenging for the subsequent image analysis. Resulting faulty AI analysis may bias the pathologist and contribute to incorrect diagnoses and, therefore, may lead to inappropriate therapy or prognosis. In this study, a pretrained AI assistance tool for the quantification of Ki-67, estrogen receptor (ER), and progesterone receptor (PR) in breast cancer was evaluated within a realistic study set representative of clinical routine on a total of 204 slides (72 Ki-67, 66 ER, and 66 PR slides). This represents the cohort with the largest image variance for AI tool evaluation to date, including 3 staining systems, 5 whole-slide scanners, and 1 microscope camera. These routine cases were collected without manual preselection and analyzed by 10 participant pathologists from 8 sites. Agreement rates for individual pathologists were found to be 87.6% for Ki-67 and 89.4% for ER/PR, respectively, between scoring with and without the assistance of the AI tool regarding clinical categories. Individual AI analysis results were confirmed by the majority of pathologists in 95.8% of Ki-67 cases and 93.2% of ER/PR cases. The statistical analysis provides evidence for high interobserver variance between pathologists (Krippendorff's α, 0.69) in conventional immunohistochemical quantification. Pathologist agreement increased slightly when using AI support (Krippendorff α, 0.72). Agreement rates of pathologist scores with and without AI assistance provide evidence for the reliability of immunohistochemical scoring with the support of the investigated AI tool under a large number of environmental variables that influence the quality of the diagnosed tissue images.

A logarithmic model for hormone receptor-positive and breast cancer patients treated with neoadjuvant chemotherapy.

OBJECTIVE: The aim of this study was to investigate the predictive importance of the previously validated log(ER)*log(PgR)/Ki-67 predictive model in a larger patient population. METHODS: Patients with hormone receptor positive/HER-2 negative and clinical node positive before chemotherapy were included. Log(ER)*log(PgR)/Ki-67 values of the patients were determined, and the ideal cutoff value was calculated using a receiver operating characteristic curve analysis. It was analyzed with a logistic regression model along with other clinical and pathological characteristics. RESULTS: A total of 181 patients were included in the study. The ideal cutoff value for pathological response was 0.12 (area under the curve=0.585, p=0.032). In the univariate analysis, no statistical correlation was observed between luminal subtype (p=0.294), histological type (p=0.238), clinical t-stage (p=0.927), progesterone receptor level (p=0.261), Ki-67 cutoff value (p=0.425), and pathological complete response. There was a positive relationship between numerical increase in age and residual disease. As the grade of the patients increased, the probability of residual disease decreased. Patients with log(ER)*log(PgR)/Ki-67 above 0.12 had an approximately threefold increased risk of residual disease when compared to patients with 0.12 and below (odds ratio: 3.17, 95% confidence interval: 1.48-6.75, p=0.003). When age, grade, and logarithmic formula were assessed together, the logarithmic formula maintained its statistical significance (odds ratio: 2.47, 95% confidence interval: 1.07-5.69, p=0.034). CONCLUSION: In hormone receptor-positive breast cancer patients receiving neoadjuvant chemotherapy, the logarithmic model has been shown in a larger patient population to be an inexpensive, easy, and rapidly applicable predictive marker that can be used to predict response.

Urothelial carcinoma in situ with "overriding" features can evade detection by mimicking umbrella cells.

Urothelial carcinoma in situ (uCIS) is typically recognized by overtly malignant cells with characteristic nuclear features; multiple histologic patterns have been described. A rare "overriding" pattern, in which uCIS tumor cells extend on top of normal urothelium, has previously been mentioned in the literature, but not well described. Herein, we report 3 cases of uCIS with "overriding" features. Detailed morphologic evaluation revealed somewhat subtle cytologic atypia: variably enlarged hyperchromatic nuclei and scattered mitotic figures but with abundant cytoplasm and limited to superficial urothelium. Immunohistochemical (IHC) analysis showed a distinctive diffuse positive aberrant p53 pattern, limited to the atypical surface urothelial cells; these cells also showed CK20+, CD44-, and increased Ki-67. In 2 cases, there was a history of urothelial carcinoma and adjacent conventional uCIS. In the third case, the "overriding" pattern was the first presentation of urothelial carcinoma; therefore, next-generation sequencing molecular testing was also performed, revealing pathogenic mutations in TERTp, TP53, and CDKN1a to further support neoplasia. Notably, the "overriding" pattern mimicked umbrella cells, which normally line surface urothelium, can have abundant cytoplasm and more variation in nuclear and cell size and shape, and show CK20+ IHC. We therefore also evaluated umbrella cell IHC patterns in adjacent benign/reactive urothelium, which showed CK20+, CD44-, p53 wild-type, and very low Ki-67 (3/3). We also reviewed 32 cases of normal/reactive urothelium: all showed p53 wild-type IHC in the umbrella cell layer (32/32). In conclusion, caution is warranted to avoid overdiagnosis of usual umbrella cells as CIS; however, "overriding" uCIS should be recognized, may have morphologic features that fall short of the diagnostic threshold of conventional CIS, and requires further study.

Ki67 in Breast Cancer Assay: An Ad Hoc Testing Recommendation from the Canadian Association of Pathologists Task Force.

Ki67, a marker of cellular proliferation, is commonly assessed in surgical pathology laboratories. In breast cancer, Ki67 is an established prognostic factor with higher levels associated with worse long-term survival. However, Ki67 IHC is considered of limited clinical use in breast cancer management largely due to issues related to standardization and reproducibility of scoring across laboratories. Recently, both the American Food and Drug Administration (FDA) and Health Canada have approved the use of abemaciclib (CDK4/6 inhibitor) for patients with HR+/HER2: high-risk early breast cancers in the adjuvant setting. Health Canada and the FDA have included a Ki67 proliferation index of ≥20% in the drug monograph. The approval was based on the results from monarchE, a phase III clinical trial in early-stage chemotherapy-naïve, HR+, HER2 negative patients at high risk of early recurrence. The study has shown significant improvement in invasive disease-free survival (IDFS) with abemaciclib when combined with adjuvant endocrine therapy at two years. Therefore, there is an urgent need by the breast pathology and medical oncology community in Canada to establish national guideline recommendations for Ki67 testing as a predictive marker in the context of abemaciclib therapy consideration. The following recommendations are based on previous IKWG publications, available guidance from the monarchE trial and expert opinions. The current recommendations are by no means final or comprehensive, and their goal is to focus on its role in the selection of patients for abemaciclib therapy. The aim of this document is to guide Canadian pathologists on how to test and report Ki67 in invasive breast cancer. Testing should be performed upon a medical oncologist's request only. Testing must be performed on treatment-naïve tumor tissue. Testing on the core biopsy is preferred; however, a well-fixed resection specimen is an acceptable alternative. Adhering to ASCO/CAP fixation guidelines for breast biomarkers is advised. Readout training is strongly recommended. Visual counting methods, other than eyeballing, should be used, with global rather than hot spot assessment preferred. Counting 100 cells in at least four areas of the tumor is recommended. The Ki67 scoring app developed to assist pathologists with scoring Ki67 proposed by the IKWG, available for free download, may be used. Automated image analysis is very promising, and laboratories with such technology are encouraged to use it as an adjunct to visual counting. A score of <5 or >30 is more robust. The task force recommends that the results are best expressed as a continuous variable. The appropriate antibody clone and staining protocols to be used may take time to address. For the time being, the task force recommends having tonsils/+pancreas on-slide control and enrollment in at least one national/international EQA program. Analytical validation remains a pending goal. Until the data become available, using local ki67 protocols is acceptable. The task force recommends participation in upcoming calibration and technical validation initiatives.

The usefulness of immunohistochemistry for phosphohistone H3 as a prognostic factor in myxoid liposarcoma.

Myxoid liposarcoma (MLS) is a common subtype of liposarcoma. Although the prognosis is generally good, there are factors known to be associated with poor prognosis. Accurate indices are important to predict prognosis. We aimed to assess the usefulness of immunohistochemistry for phosphohistone H3 (PHH3) as a potential biomarker in comparison with Ki-67 antigen and other prognostic factors. Twenty-five patients with MLS were evaluated. Age, sex, depth of tumor, tumor size, surgical margin, oncological outcome, histological grade, presence of necrosis, proportion of round cell component (RC%), PHH3 index, and Ki-67 index were examined. Prognostic factors of the examination criteria were statistically analyzed, survival rate analyses were performed using the Kaplan-Meier method, and multivariate analysis was performed using Cox proportional-hazard regression analysis. The number of PHH3-positive tumor cells and the PHH3 and Ki-67 indices demonstrated a statistical correlation with the prognosis of MLS in univariate analysis (P < 0.001, P < 0.001, P = 0.01, respectively). PHH3 index and RC% were significant factors in multivariate analysis (P = 0.03, P = 0.02). The immunohistochemistry of PHH3 may be associated with prognosis and could serve as a valid criterion of histological grade in MLS.

Yassir Alaa Muhammed Hassan Shubbar CORRELATION BETWEEN DIFFERENT CLINICOPATHOLOGICAL PARAMETERS AND MOLECULAR SUBTYPES OF FEMALE BREAST CARCINOMA IN SOUTH REGION OF IRAQ.

OBJECTIVE: The aim: To correlate variable clincopathological parameters with molecular subtypes of the breast carcinoma, which affect the prognosis and management of breast malignancy. PATIENTS AND METHODS: Materials and methods: In this study a total of 511 female patients with breast carcinoma were included, ranging from 32 to 85 years of age, with 35.8% premenopausal and 64.1% being post-menopausal. The sample slides were stained immunohistochemically for estrogen receptors (ER), progesterone receptors (PR), ki67 and HER2, the tumors were graded histologically using the Nottingham criteria system. RESULTS: Results: Most tumors (72.8%) ranged between 2 and 5 cm in size; the most common histological type of breast carcinoma (49.7%) was invasive ductal carcinoma of no special type, with grade 2 presented in 51.8% cases; most frequent stage at time of presentation was stage 3A, found in 39.9%; the most frequent molecular subtype was ER and/or PR+, Her2- with low proliferation rate ki67<14% subtype in 48.5%, and those group were more likely (statistically significant) to be older, have stage 3 breast cancer, present with tumor size between 2 and 5 cm and tend to be well differentiated histological grade (grade1), mostly with lymph node positive, and most likely have tumor type of invasive ductal carcinoma of no special type. CONCLUSION: Conclusions: the most common histological type of breast carcinoma in Iraq south was invasive ductal carcinoma of no special type and most cases showed (ER and/or PR+, HER 2-, low ki67) as the most common molecular subtype.