Use Of Ki-67 Research Articles

A Multicenter Physician Survey Evaluating the Use of Ki-67 in Breast Cancer Management in Canada

Background: Ki-67’s response to pre-operative endocrine therapy (ET) in early breast cancer is an evidence-based tool to guide adjuvant treatment decisions. Physicians across Canada were surveyed to explore current practice patterns and perceived barriers to the use of Ki-67 in practice. Methods: Physicians were invited to participate in an anonymous survey and were eligible if they prescribed systemic therapy for breast cancer in Canada. Respondents were asked to describe their usage of Ki-67, perceptions of the evidence surrounding Ki-67 ET response, and interest in future trials using this approach. Results: The survey received 48/163 responses (29.4%). The majority of respondents (97.6%) reported access to Ki-67 testing upon request. Treatment decisions for adjuvant Abemaciclib was the most common reason (97.6%), followed by adjuvant chemotherapy decisions (16.7%). Only 19.0% had used Ki-67’s response to pre-operative ET in practice. Common barriers to this approach that were identified included a lack of awareness from other providers (54.8%), an increased resource requirement (54.8%), and a lack of timely medical oncology consultation (52.4%). The majority of physicians (85.3%) reported that they would participate in future trials using the Ki-67 endocrine response, and that rate of treatment decision change (95.2%) and cost analysis (42.3%) were important endpoints. Conclusions: Despite the widespread availability of Ki-67 testing, few physicians in Canada currently use it to assess endocrine response, predominantly due to logistical and resource constraints. There is a high level of interest in participating in future trials using this strategy, which should focus on disease related outcomes, feasibility, and the financial impact on the public healthcare system.

Ki67 proliferation index in follicular lymphoma is associated with favorable outcome in patients treated with R-CHOP

Follicular lymphoma (FL) is a common, indolent small B-cell lymphoma. While the Follicular Lymphoma International Prognostic Index is widely used, reliable prognostic and predictive biomarkers are needed. A recent study suggested that architectural patterns of CD10, BCL6, and Ki67 expression may correlate with progression-free survival (PFS) in FL patients treated with chemotherapy-free regimens. We examined the prognostic and predictive utility of architectural patterns of CD10, BCL6, Ki67, and FOXP1 in 90 patients treated with immunochemotherapy (bendamustine-rituximab [BR] and R-cyclophosphamide, doxorubicin, vincristine, prednisone [CHOP]). We found that high follicular Ki67 (≥30%) was associated with longer PFS in the subgroup of patients treated with R-CHOP but not among those treated with BR. Validation of this biomarker may support routine use of Ki67 as a predictive marker in FL.

The Evolution of Ki-67 and Breast Carcinoma: Past Observations, Present Directions, and Future Considerations.

The 1983 discovery of a mouse monoclonal antibody-the Ki-67 antibody-that recognized a nuclear antigen present only in proliferating cells represented a seminal discovery for the pathologic assessment of cellular proliferation in breast cancer and other solid tumors. Cellular proliferation is a central determinant of prognosis and response to cytotoxic chemotherapy in patients with breast cancer, and since the discovery of the Ki-67 antibody, Ki-67 has evolved as an important biomarker with both prognostic and predictive potential in breast cancer. Although there is universal recognition among the international guideline recommendations of the value of Ki-67 in breast cancer, recommendations for the actual use of Ki-67 assays in the prognostic and predictive evaluation of breast cancer remain mixed, primarily due to the lack of assay standardization and inconsistent inter-observer and inter-laboratory reproducibility. The treatment of high-risk ER-positive/human epidermal growth factor receptor-2 (HER2) negative breast cancer with the recently FDA-approved drug abemaciclib relies on a quantitative assessment of Ki-67 expression in the treatment decision algorithm. This further reinforces the urgent need for standardization of Ki-67 antibody selection and staining interpretation, which will hopefully lead to multidisciplinary consensus on the use of Ki-67 as a prognostic and predictive marker in breast cancer. The goals of this review are to highlight the historical evolution of Ki-67 in breast cancer, summarize the present literature on Ki-67 in breast cancer, and discuss the evolving literature on the use of Ki-67 as a companion diagnostic biomarker in breast cancer, with consideration for the necessary changes required across pathology practices to help increase the reliability and widespread adoption of Ki-67 as a prognostic and predictive marker for breast cancer in clinical practice.

Education to Improve Ki67 Testing in Hormone Receptor-Positive/HER2-Negative Early-Stage Breast Cancer (HR+ EBC)

Abstract Introduction/Objective Ki67 is a marker of active cellular proliferation with prognostic utility in EBC. However, clinical use has been limited due to variability in assay protocols and interpretation. Recently, a Ki67 companion diagnostic received FDA approval for assessing recurrence risk and guiding therapy decision-making for high-risk HR+ EBC. We report a comprehensive program to understand current clinical use of Ki67 and identify and address educational needs of healthcare professionals regarding Ki67 testing to improve patient care. Methods/Case Report The multimodal program included a baseline survey to explore gaps in knowledge, skills, and clinical confidence in Ki67 assessment; a live, virtual webinar featuring a pathologist and an oncologist discussing practice-changing developments; and an interactive on-demand webcast developed from the webinar. Results (if a Case Study enter NA) Of the 653 survey respondents (227 self-identified a role in medical oncology and 261 in pathology), 77% indicated that they currently test for Ki67 in patients with HR+ EBC, and 64% indicated they were very or moderately knowledgeable on how to use Ki67 as a diagnostic assay. However, only 46% indicated they were very or moderately knowledgeable about the strengths and limitations of Ki67 testing methods or identifying patients who would likely benefit from CDK4/6 inhibition. At the end of the webinar, 67% to 83% of the evaluation respondents (92 – 115) indicated that the education increased their knowledge and/or confidence around how to use and test for Ki67 and identify eligible patients. There were also statistically significant gains from the webcast, including knowledge of strengths/limitations of Ki67 testing methods and confidence in the ability to identify patients for targeted therapies or clinical trials. Conclusion These data suggest some challenges in integrating Ki67 as a biomarker for clinical practice, but education can enhance knowledge and confidence on this topic. A detailed analysis of the survey and outcomes from the linked education are presented.

Concordance between Ki-67 index in invasive breast cancer and molecular signatures: EndoPredict and MammaPrint.

Identifying patients with hormone receptor-positive (HR+) early invasive breast cancer (EIBC) who benefit from adjuvant chemotherapy has improved with molecular signature tests. However, due to high cost and limited availability, alternative tests are used. The present study sought to evaluate the performance of the proliferation marker Ki-67 to identify these patients and explore its association with molecular signatures and risk stratification markers. From the San José TecSalud Hospital in Monterrey México, patients with HR+ EIBC as tested with EndoPredict or MammaPrint and Ki-67 index were identified. They were categorized into two groups: Group 1 (June 2016-August 2018) was evaluated using EndoPredict and Group 2 (June 2016-August 2018) with MammaPrint. A ≥20% Ki67 index cutoff was utilized to identify highly proliferative EIBC and an area under the receiver-operating characteristic curve and κ concordance were utilized to evaluate the performance of Ki-67 index compared to molecular signature tests. In the EndoPredict group, 54/96 patients were considered high-risk based on their EPclin score, while 57/96 patients had Ki-67 index ≥20%. However, there was no significant overall concordance between them (59.37%, κ=0.168, P=0.09), while the given risk of distant recurrence given in percentage by EPclin had a positive association with the Ki67 index (P=0.04). In the MammaPrint group, 21/70 patients were considered high-risk and 36/70 patients presented with a Ki-67 index ≥20% with a significant overall concordance (67.14%, κ=0.35, P<0.001). In addition, high Ki-67 index was associated with the Nottingham histological grade in both groups. In conclusion, there was a concordance between Ki-67 and MammaPrint risk stratification of HR+ EIBC and no concordance with the EndoPredict molecular signature, but a positive association with the given percentage of recurrence and the median Ki-67 index as the cutoff at our center. Cost-effectiveness analyses of these tests in developing countries are required; until then, the use of Ki-67 appears reasonable to aid clinical decisions, together with the other established clinicopathological variables.

Correlation of Ki67 working group prognostic risk categories with oncotype DX recurrence score (RS) in early breast cancer (EBC).

553 Background: The 21-gene RS (Oncotype DX) provides prognostic information for distant recurrence risk and is predictive of adjuvant chemotherapy benefit in hormone receptor (HR)-positive, HER-2 negative EBC. Ki67 protein expression is a proliferation marker that is determined by immunohistochemistry (IHC). The International Ki67 Working Group (IKWG) has provided guidelines for clinical use of Ki67 for prognostic classification (PMID: 33369635). The objectives of this study were to determine the correlation between IHC-measured Ki67 with the 21-gene RS, and evaluate their association with other anatomic and biologic tumor features. Methods: We performed a retrospective chart review of women with HR-positive, HER-2 negative EBC with 0-3 positive lymph nodes who had both Ki67 (via IHC using MIB-1 antibody on surgical specimen at our institutional pathology CLIA laboratory) and 21-gene RS between 2013 to 2021. Patients were categorized into Ki67 low (≤ 5%), intermediate (6-29%), and high (≥30%) based on IKWG recommendations. Overall and risk stratified agreement between Ki67 and RS were assessed using the proportion of agreement and Kappa statistic. Linear regression was used to test for associations between tumor features of ER%, PR%, and tumor size and log transformed Ki67 and RS. A t-test was used to compare average log transformed Ki67 and RS by tumor differentiation and nodal status. Results: We identified 461 patients with HR-positive BC of whom 26.7% were ≤ 50 years at diagnosis, 30% pre-menopausal and 10% node-positive. Overall, 29% (n = 137) of patients had low Ki67, 49% (n = 227) intermediate, and 21% (n = 97) high Ki67. 18% (n = 85) had RS 0-10, 67% (n = 311) had RS 11-25 and 14% (n = 65) had RS ≥ 26. There was no significant agreement (kappa &lt; 0) between Ki67 and RS (Kappa = -0.0035, p = 0.5406) in the overall population and fair agreement (kappa 0.21-0.40) between high Ki67 and RS (Kappa = 0.2510, p &lt; 0.0001). Higher ER% was significantly associated with lower RS (p &lt; 0.0001) and lower Ki67 (p = 0.0042). High tumor grade was associated with higher RS and higher Ki67 (p &lt; 0.0001). Higher PR% was associated with lower RS (p &gt; 0.0001) but not lower Ki67. Positive nodal status and larger tumor size were associated with higher Ki67 (p = 0.0081, p &lt; 0.0001) but not RS. Among the 49% of patients with intermediate Ki67 of 6-29%, the distribution of low, intermediate, and high RS was 24%, 65%, and 11%, respectively. Conclusions: In this group of patients selected to have a 21-gene RS, there was no correlation between Ki67 and RS in the overall population, and fair agreement between high Ki67 and high RS. Among the approximately one-half with an intermediate Ki67 of 6-29%, 89% would be spared chemotherapy based on a low-intermediate RS. In patients with high Ki67, 68% might be spared chemotherapy based on the RS. In the low Ki67 group, 6% had a high RS. Ki67 has limited utility in identifying patients with high or low RS.

Disparity between Ki67 measurements and tumor gene expression tests in patients with hormone-sensitive early breast cancer from the OPTIMA preliminary trial.

567 Background: Tumor gene expression tests are increasingly used in breast cancer management. The Ki67 biomarker has been proposed as an inexpensive alternative for making chemotherapy decisions, has demonstrated utility for determination of endocrine therapy responsiveness and is included in the FDA license for adjuvant abemaciclib. We have compared Ki67 measurements with tumor gene expression test results for patients included in the OPTIMA prelim trial. Methods: We compared Ki67 %staining with the results of Oncotype DX, Prosigna and MammaPrint performed by the test vendor. Ki67 was determined in a single laboratory on triplicate tissue micro-arrays using quantitative image analysis including a 10% manual quality control check. We used kappa statistics to measure agreement between tests, divided into groups using the pre-defined test score boundaries for high vs. not high risk. Results: Data were available for 259 patients. Using ≥20% staining to define a high Ki67 score, kappa values (95% CI) for agreement with Prosigna were: 0.39 (0.28-0.49); Oncotype DX: 0.27 (0.18-0.36); and MammaPrint: 0.38 (0.27-0.49). Kappa values &lt;0.2 are conventionally interpreted as showing slight agreement and 0.21-0.4 as fair agreement. A detailed breakdown of the comparisons of Ki67 with Prosigna and Oncotype DX is tabulated. Conclusions: Agreement between Ki67 and tumor gene expression tests is limited. Therefore, Ki67 values cannot accurately be used to reflect any of the molecular scores assessed here, all of which are well validated prognostic biomarkers. The use of Ki67 to determine suitability for adjuvant chemotherapy requires validation before it can replace the existing tests. Tumor gene expression tests may prove superior to Ki67 for the identification of patients likely to benefit from adjuvant abemaciclib. OPTIMA prelim is registered as ISRCTN42400492 and funded by the UK NIHR Health Technology Assessment Programme, award number 10/34/01. Clinical trial information: ISRCTN42400492. [Table: see text]

Improving Ki67 assessment concordance by the use of an artificial intelligence-empowered microscope: a multi-institutional ring study.

The nuclear proliferation biomarker Ki67 plays potential prognostic and predictive roles in breast cancer treatment. However, the lack of interpathologist consistency in Ki67 assessment limits the clinical use of Ki67. The aim of this article was to report a solution utilising an artificial intelligence (AI)-empowered microscope to improve Ki67 scoring concordance. We developed an AI-empowered microscope in which the conventional microscope was equipped with AI algorithms, and AI results were provided to pathologists in real time through augmented reality. We recruited 30 pathologists with various experience levels from five institutes to assess the Ki67 labelling index on 100 Ki67-stained slides from invasive breast cancer patients. In the first round, pathologists conducted visual assessment on a conventional microscope; in the second round, they were assisted with reference cards; and in the third round, they were assisted with an AI-empowered microscope. Experienced pathologists had better reproducibility and accuracy [intraclass correlation coefficient (ICC)=0.864, mean error=8.25%] than inexperienced pathologists (ICC=0.807, mean error=11.0%) in visual assessment. Moreover, with reference cards, inexperienced pathologists (ICC=0.836, mean error=10.7%) and experienced pathologists (ICC=0.875, mean error=7.56%) improved their reproducibility and accuracy. Finally, both experienced pathologists (ICC=0.937, mean error=4.36%) and inexperienced pathologists (ICC=0.923, mean error=4.71%) improved the reproducibility and accuracy significantly with the AI-empowered microscope. The AI-empowered microscope allows seamless integration of the AI solution into the clinical workflow, and helps pathologists to obtain higher consistency and accuracy for Ki67 assessment.

Markers of Aggressiveness in Craniopharyngiomas

Craniopharyngiomas (CP) are rare tumors that may be locally aggressive. The presence of functional estrogen receptors (ER) has been reported in CP and might be related to risk of recurrence. Our aim is to ascertain if the expression estrogen and progesterone receptor (PR) might be associated with to recurrence in CP. Material and Methods: Descriptive retrospective observational study of patients with confirmed histology of CP and tissue sample available admitted to Virgen Del Rocio University Hospital (Seville, Spain) from January 1967 to October 2020 were included. Estrogen and progesterone receptor expression was analyzed by Immunohistochemistry. Ki-67 levels were also analyzed. Two CP groups were considereded according to Ki67 levels: Group A (Ki67<10%) and group B (Ki67>10%). As all variables followed a non-parametric distribution, U Mann Whitney, Chi-Square, and Z-test with Benjamini-Hochberg correction were used when needed. Results: Our study population includes 80 patients (46 male and 34 female), with a median age at diagnosis of 34 years [10-50.00]. Twenty-six patients were under 18 years old (children) with a median age of 7 years [4.5-10.00], and 54 were adults (aged 18 and above) with a median age of 45 years [33-58.50]. Our data shows higher recurrence rates when Ki67 levels staining were higher than 10%: 8/14 (57.2%) in comparison with Ki67<10% (6/14, 42.9%, p=0.018). In children we found 6 samples with Ki67<10% and 6 samples with Ki67 >10%; recurrences were observed in 2/6 (33,3%) in the first group and in 6/6 (100%) in the second, respectively (p= 0,199). In adults, we found 9 and 3 patients for high and low Ki67 levels, respectively. Recurrences were observed in 4/9 (44,4%) in the group A and in 2/3 (66,7%) in the group B, respectively (p= 0,28). There were no differences between age groups. In patients with positive ER, we observed an increased rate of recurrence: 12/23 (52.17%) versus 2/13 (15,38%) in patients with negative ER stain but it was no significant. (p=0,21). No association between PR and recurrence was observed. Conclusions: In our series, patients with CP with high Ki67 levels are more likely to recur. No clear association between ER, PR expression and recurrence was observed. These findings support the use of Ki67 as a marker of recurrence in CP. Sources of Research Support: Spanish Ministry of Health, ISCIII co-funded with Fondos FEDER (PI16/00175) and Novartis Oncology Spain.

ES17.03 Updates in Squamous Cell Carcinoma and Neuroendocrine Tumors of the Lung

ES17.03 Updates in Squamous Cell Carcinoma and Neuroendocrine Tumors of the Lung

Re-evaluation of Negative Cone Biopsy Results with Ki-67 and p16 Immunostaining following Positive Cervical Biopsy.

Background: Cervical conization is a standard diagnostic method for precancerous lesions. However, its results could be negative despite an initially positive punch biopsy. The present study aimed to re-evaluate pathological biopsies with Ki-67 and p16 immunostaining to assess the diagnostic accuracy of punch biopsies.Methods: This retrospective study performed in Motahhari Clinic and Shahid Faghihi Hospital, (Shiraz, Iran). 88 punch and cone biopsy slides from 2007-2016 were re-evaluated by two pathologists, and the results were compared with the original diagnoses. Agreement between the initial diagnoses and re-evaluations and between our pathologists were assessed with the kappa coefficient. Twenty-two negative conization results after positive punch biopsy were re-sectioned and evaluated with Ki-67 and p16 immunostaining. Results: The overall agreement (kappa) between the primary punch diagnoses by the original pathologists and those made in the present study (by the first and second pathologists) before immunohistochemical (IHC) staining was 0.33 and 0.43, respectively. The kappa coefficient between punch biopsy diagnoses by the first and second pathologists before IHC staining was 0.73, while it increased to one after IHC staining with Ki-67 and p16. Out of the 22 specimens with the positive punch and negative cone biopsies on initial diagnosis, cervical intraepithelial neoplasia (CIN) was not confirmed in 11 specimens by our pathologists after IHC staining with Ki-67 and p16. These cases were reclassified as transitional metaplasia or acute/chronic cervicitis. Conclusion: Punch biopsy can be misdiagnosed as CIN positive, leading to unnecessary conization. The use of Ki-67 and p16 markers as appropriate ancillary tests are recommended.

Ki-67 Expression in Breast Cancer, Its Correlation with ER, PR and Other Prognostic Factors in Nineveh Province

Objectives: The aggressiveness of malignant tumors of breast can be correlated with the proliferation of neoplastic cells, and this detected by immunohistochemical study of proliferative index (Ki-67). American Society of Clinical Oncology (ASCO) does not recommend the use of Ki-67 routinely to predict the outcome of breast cancers, therefore the aim of current study is to detect the expression of Ki-67 in patients with primary breast cancer in Nineveh Province/North of Iraq and to correlate it with estrogen and progesterone receptors in addition to other prognostic factors. Methods: In this retrospective-case series study eighty cases of histologically proven primary breast carcinomas were included. The cases were collected from hospitals and private laboratories in Nineveh Province / North of Iraq and studied Immunohistochemicaly for Ki-67, estrogen receptor (ER) and progesterone receptor (PR) were done on tissue sections embedded in paraffin wax. An area with the maximum proliferation was chosen to evaluate Ki-67 and the cases with ≥20% positive nuclei were considered as high Ki-67 expression while those with <20% positive nuclei were considered as low Ki-67 expression.(10-14). The findings of Ki-67 were correlated with the age of the patients, histological type, grade of the tumors and with the estrogen and progesterone receptors. Results: The Ki-67 immunoreactivity was highly expressed in (45%) of the cases. Estrogen and progesterone receptors observed in (77.5%) and (67.5%) of the cases respectively. The Ki-67 was significantly associated with grade of tumor, estrogen receptor and progesterone receptor (P= 0.0057, 0.037 and 0.006 respectively). While the association with patientsˈage and histological types were not statistically significant. Conclusion: Ki-67 expression shows a significant direct correlation with grade of tumors and a significant inverse correlation has been shown with a well-known predictive factors, (estrogen and progesterone receptors).

Luminal A versus luminal B breast cancer: MammaTyper mRNA versus immunohistochemical subtyping with an emphasis on standardised Ki67 labelling-based or mitotic activity index-based proliferation assessment.

Proliferation assessment by the use of Ki67 is a crucial component in intrinsic subtyping of luminal breast cancers (BCs), but suffers from variability between laboratories, observers, and methods. MammaTyper is a quantitative molecular tool that measures mRNA levels of ERBB2, ESR1, PGR and MKI67 in BC, and interprets the results according to the St Gallen 2013 consensus recommendations. We compared MammaTyper with immunohistochemistry (IHC)-based subtypes, with a focus on standardised proliferation assessment. We analysed the agreement in assigning subtypes between MammaTyper and receptor IHC in 101 unifocal luminal HER2-negative early BCs of no special type. Two Ki67 counting protocols, Ki67-Global (Ki67-G) and Ki67-HotSpot (Ki67-H), recommended by the International Ki67 in BC Working Group, and the mitotic activity index (MAI) were used for proliferation assessment. The proportions of BCs identified as luminal A and as luminal B were 55% and 45% for MammaTyper, 55% and 45% for IHC+Ki67-G, 36% and 64% for IHC+Ki67-H, and 56% and 44% for IHC+MAI. The levels of agreement between MammaTyper-based and IHC-based subtyping were 84% (κ=0.679) for IHC+Ki67-G, 72% (κ=0.462) for IHC+Ki67-H, and 89% (κ=0.779) for IHC+MAI. High rates of agreement between mRNA-based and IHC-based intrinsic subtyping of luminal HER2-negative BC can be achieved. However, the agreement between IHC-based and MammaTyper-based luminal subtypes depends on the proliferation assessment method, and was highest when the MAI was used. Further comparative clinical studies are needed to determine which method is to be preferred, including analysis of cost-effectiveness.

An interobserver reproducibility analysis of size-set semiautomatic counting for Ki67 assessment in breast cancer

PurposeThe proliferation marker Ki67 has prognostic and predictive values in breast cancer, and the cutoff of the Ki67 label index (LI) is a key index for chemotherapy. However, poor interobserver consistency in Ki67 assessment has limited the clinical use of Ki67, especially in luminal cancers. Here, we reported a modified Ki67 assessment method, size-set semiautomatic counting (SSSAC) and investigated its interobserver reproducibility. MethodsOne hundred invasive breast cancer tissues were set immunostained for Ki67 in one laboratory, scanned as digital slides, and sent to 41 pathologists at the laboratories of 16 hospitals for Ki67 LI assessment using size-set semiautomatic counting (SSSAC), size-set visual assessment (SSVA) and size-set digital image analysis (SSDIA) with a specific image viewing software (Aperio Image Scope, Leica, Germany). The intraclass correlation coefficient (ICC) and Bland-Altman plot were used to evaluate interobserver reproducibility. The Wilcoxon signed-rank test was used to analyze the difference in the Ki67 values assessed by SSSAC and SSDIA. ResultsSSSAC demonstrated better interobserver reproducibility (ICC = 0.942) than SSVA (ICC = 0.802). The interobserver reproducibility was better in Ki67 homogeneously stained slides and centralized hot-spot slides than in scattered hot-spot slides. The Ki67 value assessed with SSSAC was obviously higher than that assessed with SSDIA (negative ranks (SSDIA < SSSAC): N = 80, sum of ranks = 4274.50; positive ranks (SSDIA > SSSAC): N = 17, sum of ranks = 478.50; Z = −6.837; P < 0.001). ConclusionSSSAC shows satisfactory interobserver reproducibility in the Ki67 assessment of breast cancer and may be a candidate standard method for Ki67 LI assessment in breast cancer and other malignancies.

Surrogate markers for high-risk human papillomavirus infection in oral epithelial dysplasia: A comparison of p16, Ki-67, and ProExC.

The aim of this study was to determine the utility of surrogate markers of human papillomavirus (HPV) infection in the diagnosis of HPV-associated oral epithelial dysplasia (OED). Twelve cases of oral dysplasia with histologic features of HPV infection were stained with surrogate markers for HPV (p16, Ki-67, and ProExC) on immunohistochemistry. A second group of 12 cases of oral dysplasia without histologic features of HPV infection was used for comparison. Reverse transcriptase polymerase chain reaction (RT-PCR) was used to confirm the presence of high-risk HPV (HR HPV) in p16-positive cases. All of the surrogate markers showed a statistically significant association with HPV-positive OED (P < .001). The agreement between p16 and HPV positivity was the strongest (κ = 1.00), whereas Ki-67 showed very good association with HPV (κ = 0.83), and ProExC showed good association (κ = 0.75). In each case, the agreement was statistically significant (P < .001). Overall, each of the 3 markers showed good sensitivity; however, ProExC showed the lowest specificity. The clinicopathologic features of 12 cases of HPV OED are reported. Diffuse p16 positivity is an accurate and reliable method for predicting HR HPV infection in both high and low grade cases of epithelial dysplasia with histopathologic features of HPV OED. The use of Ki-67 and ProExC did not demonstrate any additional diagnostic benefit in the diagnosis HPV OED.

Immunomorphological features of cervical dysplasia depending on the progression of papillomavirus infection in women with infertility.

Background. With the development and improvement of modern methods of immunohistochemical examination, new possibilities for studying the molecular-biological features of cervical dysplasia (CD/CIN) emerged, opening new stages of its morphogenesis. Taking into account the demographic situation in Ukraine, and the fact that incidence rate of squamous cell intraepithelial cervical lesions and infertility have a tendency to increase, it becomes apparent the need for further investigation of CIN associated with the (HPV) infection. Objective. The purpose of the study was to determine the immunohistochemical features of cervical dysplasia in women with infertility, depending on the progression of papillomavirus infection. Methods. Specific quantitative diagnostics of real-time polymerase-chain reaction with hybridization-fluorescence detection was used to detect papillomavirus infection. Immunohistochemical studies used primary monoclonal antibodies to Ki-67, p63, VEGF, p16ink4a, estrogen (ER) and progesterone receptors (PR), E-cadherin. The results obtained during the study were subjected to statistical processing by methods of variational statistics. Results. Immunomorphological features of cervical dysplasia depending on the progression of papillomavirus infection have been established in women with infertility, and the reliable influence of HPV WRC loading on the level of expression of molecular-biological markers depending on the severity of cervical dysplasia has been demonstrated. Conclusion.Therefore, the use of Ki-67, p63, pl6ink4a, VEGF, E-cadherin markers is the most optimal for the implementation of the diagnostic process and for determining the course of CIN, since the change in their expression most often corresponded to the severity of CIN.

Observational Study Examining the Diagnostic Practice of Ki67 Staining for Melanocytic Lesions.

Dermatopathologists routinely use Ki67 immunostaining to assess atypical melanocytic lesions with a dermal component to determine whether an ambiguous tumor is melanoma. However, there is no universal standard of use for Ki67 in melanocytic neoplasms. We sought to observe the real-world use of Ki67 in the diagnosis of melanocytic lesions and establish a best practice recommendation. We searched dermatopathology reports from 2 academic practices for melanocytic lesions in which Ki67 staining was used for diagnosis. The proliferation rate was compared between cases diagnosed as benign (not requiring re-excision), moderate to severely dysplastic or atypical Spitz nevi (requiring re-excision), and malignant melanoma. The use of other melanocytic markers and consensus review was also recorded and compared between institutions. Pathology reports for 106 cases were reviewed. A high Ki67 proliferation rate (n = 18) favored a diagnosis of melanoma or nevi requiring re-excision (15/18, 83.3%) versus a benign nevus (3/18, 16.67%). A high Ki67 rate was 71.4%-90.9% sensitive and 40%-56% specific for the diagnosis of nevus requiring re-excision or melanoma. Institutional practices differed in regard to reporting of Ki67 staining, the use of multiple markers in the workup of atypical melanocytic lesions (HMB45, Melan-A, Ki67 being most common), and consensus review. A negative or low Ki67 proliferation rate correlates well with rendering of a benign diagnosis. However, a low proliferation rate does not preclude the diagnosis of melanoma. Ki67 staining is most commonly used as an ancillary test to support a diagnosis after other factors have been considered, such as histopathologic morphology and results of additional concurrently used stains.

Predictive Role of Ki-67 and Proliferative-Cell Nuclear Antigen (PCNA) in Recurrent Cholesteatoma.

To investigate the potential use of Ki-67 and pronuclear cell antigen (PCNA) as indicators of recurrent cholesteatoma. Patients who had been diagnosed with cholesteatoma and who had undergone canal wall-down mastoidectomy were included in this study. Subjects were divided into two groups: recurrent and non-recurrent (i.e., cases without recurrence for at least 2 years). Ossicular pathologies were recorded. Histopathologic specimens were stained for Ki-67 and PCNA and the percentages of stained cells were calculated. Neither group demonstrated a significant difference in terms of total Ki-67 per cell, Ki-67-stained cell counts, Ki-67-staining percentages, total PCNA per cell, PCNA-stained cell counts, or PCNA-staining percentages (p>0.05). No significant relationship was noted between the staining percentages for either Ki-67 or PCNA and the incudostapedial involvement (p>0.05); however, a significant relationship was noted between Ki-67 staining and malleus involvement (p<0.05). Although the recurrent and non-recurrent cholesteatoma groups showed no significant differences in terms of the percentages of stained cells for either Ki-67 or PCNA, we detected high Ki-67 staining in the malleus involvement group. We concluded that cell-proliferation markers could not be defined as indicators of recurrence of cholesteatoma, but they could be defined as indicators of destructive patterns of this disease.

Does integration of Magee equations into routine clinical practice affect whether oncologists order the Oncotype DX test? A prospective randomized trial.

The three Magee Equations provide an estimate of the Oncotype DX recurrence score using commonly available clinicopathologic information (tumour size, grade, oestrogen receptor, progesterone receptor, HER2, and Ki67). We assessed whether integration of Magee Equations into routine clinical practice affected the frequency of Oncotype DX requests. Patients with newly diagnosed, node negative, hormone receptor positive, and HER2 negative invasive breast cancer were randomized to undergo a Magee calculation or not. At the first clinic assessment, the oncologist was provided with all routinely available clinicopathologic information (including Ki67) either with or without the results of Magee Equations. Primary outcome was frequency of Oncotype DX ordering. Secondary outcomes included frequency of chemotherapy use, time to commencement of radiotherapy, or systemic therapy. Physician comfort with systemic therapy choices and the use of Ki67 and Magee Equations was also assessed. Data from 175 randomized patients was available, 84 patients (48%) with and 91 (52%) without calculated Magee Equations. Oncotype DX was ordered in 10 (12.05%) and 13 (14.44%) (RR 0.83, 0.39-1.80; P=0.64) in the Magee and no Magee groups, respectively. There were no statistically or clinically significant differences between the randomized groups for any of the secondary outcomes. Availability of both Ki67 and Magee Equations was associated with increased physician comfort around systemic treatment decisions. In a practice where Ki67 is routinely available, addition of Magee Equations into routine clinic practice was not associated with a reduction in Oncotype DX use. Availability of both Ki67 and Magee Equations did however increase physician comfort with systemic therapy decisions.

Abstract P3-08-14: Prediction of distant recurrence in low risk early breast cancer by RT-qPCR based subtyping using MammaTyper®

Abstract Background: Estrogen receptor (ER/ESR1), progesterone receptor (PR/PGR) and epidermal growth factor receptor 2 (HER2/ERBB2) are routinely assessed by immunohistochemistry (IHC) during workup of breast cancer samples. The routine use of Ki67 (MKI67) IHC assessment in the context of breast cancer subtyping, however, remains controversial, due to poor reproducibility and lack of standardization. The MammaTyper® test is an in-vitro diagnostic (IVD) test which measures the expression status of the four breast cancer biomarkers ERBB2, ESR1, PGR and MKI67 on the mRNA level via reverse transcription-quantitative PCR (RT-qPCR) and has demonstrated a high degree of reproducibility in the assessment of the four markers. In this retrospective analysis we assessed the prognostic power of molecular subtyping by MammaTyper® in archived samples from low risk early breast cancers treated with adjuvant endocrine therapy only. Methods: ER+/HER2- (according to initial diagnosis) FFPE breast cancer samples from patients treated with adjuvant endocrine therapy only were obtained from 6 different centers. Tumor cellularity was assessed by H&amp;E staining and RNA was extracted from samples with a tumor cell content of ≥20% using a bead-based RNA purification kit (RNXtract®). Total RNA was then used as input for MammaTyper® RT-qPCR. Expression values were classified as positive or negative for each marker based on predefined cutoff values. Tumor subtypes were assigned to each sample based on the combination of binary (pos/neg) single marker expression status according the St Gallen surrogate subtype definition. Distant disease free survival of Luminal A-like samples vs. samples with other subtypes was assessed by Kaplan Meier analysis and Cox regression using SAS version 9.4. Results: The final analysis included 319 samples with sufficient tumor cellularity and RNA content for reliable analysis. The rate of distant recurrence in the analyzed set was 8.5%. Median follow up was 7.8 years. The MammaTyper® test called 60% (192) of samples as Luminal-A-like (4.7% (9) distant events), 37% (119) as Luminal B-like (HER2 negative) (13.4% (16) distant events), 1.3% (4) as Triple negative (ductal) (25% (1) distant events), 0.6% (2) as “not defined according to St Gallen” (ESR1-/PGR+) (50% (1) distant events) and 0.6% (2) as Luminal B-like (HER2 positive) (no distant events). When comparing Luminal A-like samples with the samples of the other subtypes in survival analysis, Luminal A-like samples had a significantly better distant disease free survival when assessing samples from patients with pN0 status (278) (p=0.0177, HR=0.344 (95% CI 0.137-0.866), pN1 status (0-3 affected nodes) (314) (p=0.0153, HR=0.374 (95% CI 0.163-0.855) as well as for all samples (p=0.0032, HR=0.319 (95% CI 0.143-0.711). Conclusion: Determination of HER2, ER, PR and Ki67 mRNA levels allows molecular subtyping according to the St Gallen surrogate subtype definition. Low risk of distant recurrence could be confirmed for the MammaTyper® Luminal A-like samples suggesting that for this patient group endocrine treatment alone may be sufficient. The high degree of standardization of mRNA measurement may drive the use of the Ki67/MKI67 biomarker in routine breast cancer pathology. Citation Format: Laible M, Hartmann K, Gürtler C, Anzeneder T, Weber S, Keller T, Sahin U. Prediction of distant recurrence in low risk early breast cancer by RT-qPCR based subtyping using MammaTyper® [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-08-14.