Ki-67 Labeling Index Research Articles

Solitary fibrous tumor of the prostate: Case report and review of the literature

Solitary Fibrous Tumor (SFT), typically found in the pleura, is exceptionally rare in the prostate. We present the case of a 54-year-old man with prostatic SFT, initially revealed as an abdominopelvic mass. Subsequent investigations shown a vascular tumor. The pathological examination found a 23 cm tumor originating from the prostate, composed of short spindle-shaped and polygonal cells with mild nuclear atypia. Occasional mitoses were observed, with vascular invasion. Immunohistochemically, the tumor cells strongly expressed CD34 and STAT6. The maximum Ki-67 labeling index for the tumor cells was 4%. This case report has highlighted one of the rare occurrences of solitary fibrous tumor. A comprehensive microscopic examination paired with an immunohistochemical analysis will be necessary to establish an accurate diagnosis.

SLC34A2 promotes cell proliferation by activating STX17-mediated autophagy in esophageal squamous cell carcinoma.

Solute carrier family 34 member 2 (SLC34A2) has been implicated in the development of various malignancies. However, the clinical significance and underlying molecular mechanisms of SLC34A2 in esophageal squamous cell carcinoma (ESCC) remain elusive. Western blotting, quantitative real-time PCR and immunohistochemistry were utilized to evaluate the expression levels of SLC34A2 mRNA/protein in ESCC cell lines or tissues. Kaplan-Meier curves were employed for survival analysis. CCK-8, colony formation, EdU and xenograft tumor model assays were conducted to determine the impact of SLC34A2 on ESCC cell proliferation. Cell cycle was examined using flow cytometry. RNA-sequencing and enrichment analysis were carried out to explore the potential signaling pathways. The autophagic flux was evaluated by western blotting, mRFP-GFP-LC3 reporter system and transmission electron microscopy. Immunoprecipitation and mass spectrometry were utilized for identification of potential SLC34A2-interacting proteins. Cycloheximide (CHX) chase and ubiquitination assays were conducted to test the protein stability. The expression of SLC34A2 was significantly upregulated in ESCC and correlated with unfavorable clinicopathologic characteristics particularly the Ki-67 labeling index and poor prognosis of ESCC patients. Overexpression of SLC34A2 promoted ESCC cell proliferation, while silencing SLC34A2 had the opposite effect. Moreover, SLC34A2 induced autophagy to promote ESCC cell proliferation, whereas inhibition of autophagy suppressed the proliferation of ESCC cells. Further studies showed that SLC34A2 interacted with an autophagy-related protein STX17 to promote autophagy and proliferation of ESCC cells by inhibiting the ubiquitination and degradation of STX17. These findings indicate that SLC34A2 may serve as a prognostic biomarker for ESCC.

Solitary Fibrous Tumor of the Prostate: Case Report and Review of the Literature

Solitary fibrous tumor (SFT), typically found in the pleura, is exceptionally rare in the prostate. We present the case of a 54-year-old man with prostatic SFT, initially revealed as an abdominopelvic mass. Subsequent investigations shown a vascular tumor. The pathological examination found a 23-cm tumor originating from the prostate, composed of short spindle-shaped and polygonal cells with mild nuclear atypia. Occasional mitoses were observed, with vascular invasion. Immunohistochemically, the tumor cells strongly expressed CD34 and STAT6. The maximum Ki-67 labeling index for the tumor cells was 4%. This case report has highlighted one of the rare occurrences of solitary fibrous tumor. A comprehensive microscopic examination paired with an immunohistochemical analysis will be necessary to establish an accurate diagnosis.

Primary omental smooth muscle tumor in an adult male: a diagnostic dilemma for leiomyoma: a case report

BackgroundThe greater omentum comprises peritoneal, adipose, vascular, and lymphoid tissues. Most omental malignancies are metastatic tumors, and the incidence of primary tumors is rare. We report on a prior omental smooth muscle tumor case in an adult male patient.Case presentationA 54-year-old Japanese male patient with no relevant medical history was diagnosed with an abdominal mass during a routine medical checkup. Subsequent contrast-enhanced computed tomography revealed a mass of approximately 3 cm in size in the greater omentum, and a laparotomy was performed. A 27 × 25 × 20 mm raised lesion was found in the omentum. Microscopically, spindle cells were observed and arranged in whorls and fascicles. Individual tumor cells had short spindle-shaped nuclei with slightly increased chromatin and were characterized by a slightly eosinophilic, spindle-shaped cytoplasm. The mitotic count was less than 1 per 50 high-power fields. The tumor cells showed positive immunoreactivity for α smooth muscle actin, HHF35, and desmin on immunohistochemical examination. The Ki-67 labeling index using the average method was 1.76% (261/14806). No immunoreactivity was observed for any of the other tested markers. We considered leiomyoma owing to a lack of malignant findings. However, primary omental leiomyoma has rarely been reported, and it can be difficult to completely rule out the malignant potential of smooth muscle tumors in soft tissues. Our patient was decisively diagnosed with a primary omental smooth muscle tumor considering leiomyoma. Consequently, the patient did not undergo additional adjuvant therapy and was followed up. The patient was satisfied with treatment and showed neither recurrence nor metastasis at the 13-month postoperative follow-up.Discussion and conclusionWe encountered a primary smooth muscle tumor of the greater omentum with no histological findings suggestive of malignancy in an adult male patient. However, omental smooth muscle tumors are extremely difficult to define as benign, requiring careful diagnosis. Further case reports with long-term follow-up and case series are required to determine whether a true omental benign smooth muscle tumor (leiomyoma) exists. In addition, proper interpretation of the Ki-67 labeling index should be established. This case study is a foundation for future research.

Abstract PO4-01-08: Co-expression of estrogen receptor (ER), progesterone receptor (PR), and Ki67 in a single breast cancer cell indicates a favorable prognosis in ER-positive breast cancer

Abstract Background: ER-positive breast cancer is biologically and clinically divided into two subtypes: luminal-A and luminal-B. This classification is mainly based on the status of cellular proliferation. At least two different pathways drive cellular proliferation in ER-positive breast cancer. One is a classical pathway where ER binds to estrogen responsive element (ERE), which leads to the expression of downstream molecules, including PR. The other is a non-classical pathway where a complex of ER and relevant factors bind to different sites than ERE. Growth factor signaling has been suggested to potentiate a non-classical pathway. We hypothesized that examining PR status in ER-positive proliferating cells could tell which pathway is more dominant in ER-positive breast cancer. Methods: To test the hypothesis, we used a newly developed triplex immunohistochemistry (IHC) that detects three molecules simultaneously under bright-field microscopy. Postmenopausal patients who were treated with neoadjuvant endocrine therapy with aromatase inhibitors from January 2007 to September 2016 at Saitama Cancer Center were included in this study. ER, PR, and Ki67 expressions were assessed in a single slide using the triplex IHC assay with anti-ER antibody (clone SP1), anti-PR antibody (clone 1E2), and anti-Ki67 antibody (clone 30-9). ER, PR and Ki67 expression was assessed in a single cell nucleus of cancer cells (567 to 4871 cells) from multiple areas in each case. An ER-positive proliferating cell was defined as an ER-positive and Ki67-positive cell. PR status in ER-positive proliferating cells was assessed. When PR was expressed in more than 50% of ER-positive proliferating cells in a clinical case, the tumor was categorized as the PR-positive group. Luminal A and luminal B breast cancers were defined based on the pre-treatment Ki67 labeling index with a cut-off of 14 %. Statistical analyses included the Mann-Whitney test, the log-rank test, and the Cox proportional hazard model. Results: Pre-treatment tissues from 55 patients were evaluated. The median age was 62 (range: 54 to 80) years. The patients were grouped into PR-positive and PR-negative groups. The two groups had no differences in age and pre-treatment T and N stages. The median pre-treatment Ki67 labeling index was 5.9 % in the PR-positive group and 9.9 % in the PR-negative group, which showed a statistically significant difference (P = 0.01). Clinical response to neoadjuvant endocrine therapy was compared, and no difference was observed. The median post-treatment Ki67 labeling index was 3.6 % in the PR-positive group and 13.1 % in the PR-negative group with a significant difference (P = 0.035). The survival was compared between the two groups. The PR-positive group showed a significantly more favorable disease-free survival (DFS) than the PR-negative group (P = 0.0079). To adjust for the background differences including Ki67 and PR status, a multivariate analysis was performed and showed that the PR-positive group had a significantly better DFS than the PR-negative group independent of clinical stage, Ki67 labeling index, and PR status (P = 0.042). Breast cancer-specific survival (BCSS) was also better in the PR-positive group than in the PR-negative group after adjusting for clinical stage, Ki67 labeling index, and PR status (P = 0.043). Interestingly, among patients with luminal A tumors, those in the PR-positive group showed a better DFS than those in the PR-negative group (P = 0.022). Conclusion: PR status in ER-positive proliferating cells was an independent prognostic factor in DFS and BCSS and divided patients with luminal A tumors further into two prognostic groups. Citation Format: Takayuki Ueno, Rie Horii, Hiroshi Matsumoto, Makiko Ono, Yurina Maeshima, Hiroaki Nitta. Co-expression of estrogen receptor (ER), progesterone receptor (PR), and Ki67 in a single breast cancer cell indicates a favorable prognosis in ER-positive breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-01-08.

Abstract PO4-26-04: Immunolocalization of cytoplasmic ER in ER-negative breast carcinoma as a potent favorable prognostic predictor

Abstract Background: It is known that estrogen receptor (ER) has extranuclear signaling functions in addition to classical genomic pathway, and estrogenic actions have been reported in ER-negative breast carcinoma cells. However, significance of cytoplasmic-ER immunoreactivity has not been reported in ER-negative breast carcinoma tissues. Methods: We immunolocalized cytoplasmic ER in 155 ER-negative breast carcinoma tissues and evaluated its clinicopathological significance including the prognosis. As a comparative cohort set, we also used 142 ER-positive breast carcinomas. Results: Cytoplasmic-ER immunoreactivity was detected in the carcinoma cells, but not in the non-neoplastic mammary epithelium. Cytoplasmic-ER immunoreactivity was positive in the 35 out of 155 (23%) ER-negative breast carcinoma cases, whereas it was detected only in 2 out of 142 (1.4%) ER-positive cases. Cytoplasmic ER status was positively associated with cytoplasmic-PR status, but inversely associated with Ki67 labeling index or distant free-relapse survival rate. Moreover, cytoplasmic-ER status turned out to be an independent good prognostic factor for both distant relapse-free survival and breast cancer specific survival. Conclusion: These findings suggested that cytoplasmic ER plays important roles in the ER-negative breast carcinoma, and cytoplasmic ER is a potent good prognostic factor. (accepted in Acta Histochemica et Cytochemica, 2023/Jun/27) Citation Format: Akiko Ebata, Takashi Suzuki, Narumi Harada-Shoji, Yohei Hamanaka, Minoru Miyashita, Erina Iwabuchi, Kiyoshi Takagi, Yasuhiro Miki, Hiroshi Tada, Takanori Ishida. Immunolocalization of cytoplasmic ER in ER-negative breast carcinoma as a potent favorable prognostic predictor [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-26-04.

Abstract RF01-02: A randomized Phase I pre-operative window trial of transdermal endoxifen in women planning mastectomy: evaluation of dermal safety, intra-mammary drug distribution, and biologic effects

Abstract Background: Breast cancer prevention requires only local exposure of the breast to active drug but oral preventive agents entail systemic exposure, with resultant adverse effects, limiting acceptance by high-risk women. Drug-delivery through the breast skin is an attractive option, but requires demonstration of dermal safety and drug distribution throughout the breast. We formulated the tamoxifen metabolite (E/Z)-endoxifen in a hydroalcoholic/oleic acid gel for transdermal delivery. We tested this in a placebo-controlled, double-blinded Phase I trial with dose escalation from 10 to 20 mg daily and evaluated dermal safety, intra-mammary drug distribution, and biologic effects in DCIS or invasive cancers. Methods: Women planning mastectomy for therapy for Stage 0-III breast cancer, or surgical risk reduction (N=32) were randomized (2:1) to placebo-gel or endoxifen-gel applied to the skin of both breasts for 3-5 weeks. Our primary endpoint, dermal safety was evaluated using the modified NCI Common Terminology Criteria for Adverse Events version 4. Endoxifen concentration, and modulation of circulating tamoxifen biomarkers were evaluated to demonstrate minimal systemic effects. Plasma and tissue concentration of endoxifen were determined using Liquid Chromatography – Tandem Mass Spectrometry. Tamoxifen-responsive circulating markers, insulin-like growth factor 1 (IGF1) and sex hormone-binding globulin (SHBG), were measured with enzyme-linked immunosorbent assays. Finally, we explored anti-cancer efficacy in tumors by measuring the modulation of tumor cell proliferation (Ki67 labeling index) and gene expression associated with tamoxifen response in proliferation (BIRC5, MKI67, MYBL2, CCNB1, AURKA), cell cycle (UBE2C, PLK1, CEP55, CDK1, RRM2, TOP2A, PTTG1), cancer-associated stromal genes of invasion (FN1, SERPINH1, PLOD2, PDGFA, ITGAV) and extracellular matrix (COL11A1, SPP1, COMP, BGN). Within-participant changes between baseline and post-treatment were assessed using the Wilcoxon signed rank test. Differences between treatment arms were assessed using the Wilcoxon rank sum test and the Kruskal-Wallis test. Results: endoxifen-gel at both doses incurred no dermal or systemic toxicity nor change in circulating biomarkers (IGF1, SHBG) compared to placebo. All treated breasts contained endoxifen at each of five sampling locations; the median per-person tissue concentration in the treated participants was 0.6 ng/g (IQR 0.4-1.6), significantly higher (p < 0.001) than the median plasma concentration (0.2 ng/mL, IQR 0.2-0.2). The median ratio of the more potent (Z)-isomer to (E)-isomer at each breast location was 1.5 (IQR 0.96-2.54, p < 0.05). We observed non-significant overall reduction in tumor Ki67 LI (median change -1.7 with IQR -5.8, 3.6) and gene expression of MKI67 and the genes associated with proliferation, and cell cycle. However, downregulation of invasion signature genes (FN1, SERPINH1, PLOD2, PDGFA, ITGAV) was significant (p=0.03) and a cluster of six participants demonstrated a consistent reduction of MKI67 and multiple gene signatures suggesting the possibility that their tumors might be early responders to low endoxifen exposure within 3 to 4 weeks of treatment. Conclusions: our evaluation of transdermal (E/Z) endoxifen 10 and 20 mg in hydroalcoholic/oleic acid formulation demonstrates lack of early dermal toxicity, and good tolerability over a month or so of therapy. Our findings warrant development of transdermal formulations of (Z)-endoxifen with better dermal permeation for a Phase 2 breast cancer prevention trial compared to low-dose oral SERMs so that women at high-risk for breast cancer may have a range of cancer prevention options available to them. Citation Format: Oukseub Lee, Latifa Bazzi, Yanfei Xu, Erik Pearson, Minhua Wang, Omid Hosseini, Azza Akasha, Jennifer Choi, Masha Kocherginsky, Kelly Benante, Thomas Helland, Gunnar Mellgren, Eileen Dimond, Marjorie Perloff, Brandy Heckman-Stoddard, Seema Khan, Scott Karlan, Melissa Pilewskie. A randomized Phase I pre-operative window trial of transdermal endoxifen in women planning mastectomy: evaluation of dermal safety, intra-mammary drug distribution, and biologic effects [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr RF01-02.

Clinical, pathologic, and genomic characteristics of two pediatric glioneuronal tumors with a CLIP2::MET fusion

Integration of molecular data with histologic, radiologic, and clinical features is imperative for accurate diagnosis of pediatric central nervous system (CNS) tumors. Whole transcriptome RNA sequencing (RNAseq), a genome-wide and non-targeted approach, allows for the detection of novel or rare oncogenic fusion events that contribute to the tumorigenesis of a substantial portion of pediatric low- and high-grade glial and glioneuronal tumors. We present two cases of pediatric glioneuronal tumors occurring in the occipital region with a CLIP2::MET fusion detected by RNAseq. Chromosomal microarray studies revealed copy number alterations involving chromosomes 1, 7, and 22 in both tumors, with Case 2 having an interstitial deletion breakpoint in the CLIP2 gene. By methylation profiling, neither tumor had a match result, but both clustered with the low-grade glial/glioneuronal tumors in the UMAP. Histologically, in both instances, our cases displayed characteristics of a low-grade tumor, notably the absence of mitotic activity, low Ki-67 labeling index and the lack of necrosis and microvascular proliferation. Glial and neuronal markers were positive for both tumors. Clinically, both patients achieved clinical stability post-tumor resection and remain under regular surveillance imaging without adjuvant therapy at the last follow-up, 6 months and 3 years, respectively. This is the first case report demonstrating the presence of a CLIP2::MET fusion in two pediatric low-grade glioneuronal tumors (GNT). Conservative clinical management may be considered for patients with GNT and CLIP2:MET fusion in the context of histologically low-grade features.

Utility of solid area diameter in management of cystic papillary thyroid carcinoma.

Papillary thyroid carcinoma (PTC) with marked cystic formation (CPTC) is not a subtype of PTC, and its clinical characteristics have not been fully investigated. This study aimed to clarify the clinical and pathological characteristics of CPTC and propose important indicators for its clinical management. Thirty-three CPTC nodules with cystic areas occupying >50% of their volume were examined. Two matched controls (MCs) were prepared, one with tumor diameter matched for whole tumor diameter (WTD) of CPTCs and the other with tumor diameter matched for solid area diameter (SAD) of CPTCs. The mean age of patients with CPTC was 55.2 years significantly older than that in SAD-MCs. Of the CPTCs, 69.7% were classified as highly suspicious by ultrasonography, and the prevalence was lower than that in WTD-MCs (88.9%) and SAD-MCs (91.5%). Total thyroidectomy was performed in 69.7% of CPTC cases, which was significantly less frequent than that in WDT-MCs (91.7%) and similar to that in SAD-MCs (76.1%). Histologically, CPTCs exhibited two characteristic findings: invasion from the solid area into the surrounding normal thyroid tissue and granulation tissue around the cystic wall. The frequencies of the cases with pathological lateral node metastasis, extrathyroidal extension, and Ki-67 labeling index ≥5% in CPTCs were significantly lower than those in WTD-MCs and relatively similar to those in SAD-MCs. In the surgical strategy and prognosis of CPTC, the evaluation of tumor size should be based on SAD rather than on WTD. We advocate measuring not only WTD but also SAD in CPTC.

Meningioma Prognostic Tool Based on Correlation of Histopathological Grading and Immunohistochemistry.

Meningiomas are slow-growing brain neoplasms classified into three grades based on morphological criteria. While these grades are simple, they do not always correlate with patient outcomes. This study aimed to evaluate the status of estrogen receptor (ER), progesterone receptor (PR), and proliferation marker Ki-67/molecular immunology borstel-1 (MIB-1) in the three grades of meningioma. We evaluated the data of meningioma patients who were seen in our tertiary center over 10 years-8.5 years retrospectively and 1.5 years prospectively. Their archival hematoxylin and eosin stained slides were reviewed and re-graded according to the World Health Organization 2021 criteria. Immunohistochemical analysis for ER, PR, and Ki-67 was performed on all grade 2 and grade 3 meningiomas and 30 cases of grade 1 formalin-fixed, paraffin-embedded samples. Of the 276 cases included in the study, there were 231 (83.7%) cases of grade 1 meningioma, 34 (12.3%) cases of grade 2, and 11 (4.0%) cases of grade 3. ER was positive in 26.0% of grade 1 tumors, 5.8% of grade 2, and 0.0% of grade 3. PR was positive in 70.0% of grade 1 tumors, 20.0% of grade 2, and 18.0% of grade 3. The Ki-67/MIB-1 labeling index (LI) was 2.1 in grade 1, 6.3 in grade 2, and 13.4 in grade 3 tumors. For both PR and Ki-67, the differences between grades 1, 2, and 3 tumors were significant (p < 0.001). There was a significant inverse relationship between mean Ki-67 LI and PR status, with increasing grade of tumor. Ki-67/MIB-1 LI has significant positive correlations with meningioma grade and its recurrence, which makes it a useful auxiliary method for the routine assessment of meningiomas, especially in patients with borderline atypia. The expression of PR, on the other hand, is a positive prognostic indicator and has a substantial correlation with histological grade. In cases of subtotal resection, high proliferative/recurrence rates, and borderline histopathology, the PR status in combination with the MIB-1 LI can offer insights into the behavior and the recurrence probability of a meningioma.

Abstract 6273: GGCT expression is a useful marker for the diagnosis of follicular thyroid carcinoma

Abstract Background: Follicular thyroid carcinoma (FTC) and follicular adenoma (FA) have similar histological findings. FTC is distinct from FA based on the presence of capsular or vascular invasion in the tissues, but it is difficult to confirm the diagnosis in some cases. In this study, we aimed to establish useful molecular maker for differential diagnosis between FTC and FA. Methods: This study included FTC (n = 32), FA (n = 64), and follicular tumors of uncertain malignant potential (FT-UMP, n = 5). Invasive front tissue and tumor center tissue from 3 cases of FTC were collected using a laser microdissection system; RNA was extracted, followed by microarray analysis to examine molecules that were commonly highly expressed in the invasive front. Subsequently, immunohistochemical staining of gamma-glutamyl cyclotransferase (GGCT) was performed. For assessment of GGCT expression, the intensity of the nuclear staining was stratified using a four-tiered scale (0 to 3) and percentage of positive cells (0-100%) in the hotspot. Multiplying intensity score and percent of positive cells, an expression score ranging from 0 to 300 was calculated. The Ki-67 labeling index was examined in 20 cases of FTC, 25 cases of FA, and 4 cases of FT-UMP from the same cohort. We counted at least 2,000 tumor cells in the hot spot for the assessment of Ki-67 labeling index. Results: Microarray analysis revealed GGCT exhibited high expression levels at the invasive front of FTC. In immunohistochemical assessment, GGCT expression scores were significantly higher in FTC than in FA (118.5 ± 51.4 vs. 57.3 ± 34.7, p &amp;lt; 0.0001). The median Ki-67 labeling index were 3.9% (range 0.2 - 16.1) for FTC and 2.4% (range 0.3 - 7.0) for FA. FTC showed a higher Ki-67 index than FA (Wilcoxon rank sum test, p = 0.0444). With GGCT expression score, applying a cutoff value of 101.1, the distinction between FTC and FA resulted in a sensitivity of 68.8% and a specificity of 87.5% (AUC: 0.832). With Ki-67 labeling index, applying a cutoff value of 4.0%, the distinction between FTC and FA resulted in a sensitivity of 50.0% and a specificity of 80.0% (AUC: 0.677). The GGCT expression score was positively related with the Ki-67 labeling index in the FTC cases. (Spearman's ρ = 0.5293, p = 0.0164). There were no significant associations between GGCT expression scores and clinicopathological parameters, including age, gender, tumor diameter, pT stage, pN stage, pattern of capsular invasion, number of foci of vascular invasion, and the presence of distant metastasis. Conclusions: GGCT is a potential marker for differentiating FTC from FA. The GGCT expression of FTC may contribute to estimating the invasive activity and proliferative activity. Citation Format: Toshiyuki Mitsuhashi, Sachiko Ogasawara, Masamichi Nakayama, Reiichiro Kondo, Jun Akiba, Kenta Murotani, Takeharu Ono, Fumihiko Sato, Hirohito Umeno, Hirohisa Yano. GGCT expression is a useful marker for the diagnosis of follicular thyroid carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6273.

Abstract 3804: Multiparameter cell-cycle measurement enables a better assessment of cancer aggressiveness than Ki67 LI alone

Abstract Background: Ki67 is expressed in the G1, S, G2 and M phase of the cell cycle. Immunohistochemical determination of the Ki67 labeling index (LI) is a clinically well-established tool for assessing the proliferative activity of tumors and critical clinical decisions are based on this parameter. Other cell cycle associated proteins have been evaluated for clinical utility much less intensively. This for example includes minichromosome maintenance-3 (MCM3) which is expressed earlier in the cell cycle than Ki67. Design: To evaluate the difference and potential synergy between of Ki67 and MCM3 based proliferation indices, both proteins were analyzed by multiplex fluorescent immunohistochemistry in more than 1,580 colorectal carcinomas that were available in a tissue microarray format and results were compared with clinico-pathological parameters (pT, pN, grade, MSI, p53 status). A deep learning-based framework comprising a deep-learning based algorithm for automated cell and marker detection was used for image analysis. Results: In our 1,583 evaluable colorectal cancers, the average Ki67 LI was 69% and the average MCM3-LI was 67%. There was a significant overlap between Ki67 and MCM3 staining: Of all panCK positive tumor cells, 56% were positive for both Ki67 and MCM3, 11% were only positive for Ki67, 8% showed positivity only for MCM3, and 25% were negative for both markers. According to the expression of Ki67 and MCM3, the following compartments of proliferating cells were defined: early (MCM3+/Ki67−), intermediate (MCM3+/Ki67+), and late phase of the cell cycle (MCM3−/Ki67+) as well as full proliferation (MCM3+ or Ki67+). Comparison with clinico-pathological parameters revealed the best p-values for the MCM3 LI in the comparison with pT (p=2.7e−8), nodal metastasis (p=0.0002), and p53 alterations (p=6e−11) while the “full proliferation” LI was most tightly linked to microsatellite instability (p=1e−10). The Ki67 LI was best correlated to the grade (p=0.01). Conclusion: The combined analysis of MCM3 and Ki67 enables the distinction of cells in early, intermediate, and late phase of the cell cycle. At least in colorectal cancer - a highly proliferative neoplasm - MCM3 quantification alone or in combination with Ki67 often resulted in stronger relationships with clinicopathological parameters than the Ki67 LI alone. These results suggest that a more subtle analysis of cell cycle proteins might enable a better evaluation of cancer aggressiveness than Ki67 measurement alone. Citation Format: Jan H. Mueller, Julia Ebner, Zhihao Huang, Maximilian Lennartz, Claudia Hube-Magg, Frank Jacobsen, Stefan Steurer, Christian Bernreuther, Till S. Clauditz, Andreas H. Marx, Till Krech, Eike Burandt, Guido Sauter, Ronald Simon, Sarah Minner, Elena Bady. Multiparameter cell-cycle measurement enables a better assessment of cancer aggressiveness than Ki67 LI alone [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3804.

Factors associated with engraftment success of patient-derived xenografts of breast cancer

BackgroundPatient-derived xenograft (PDX) models serve as a valuable tool for the preclinical evaluation of novel therapies. They closely replicate the genetic, phenotypic, and histopathological characteristics of primary breast tumors. Despite their promise, the rate of successful PDX engraftment is various in the literature. This study aimed to identify the key factors associated with successful PDX engraftment of primary breast cancer.MethodsWe integrated clinicopathological data with morphological attributes quantified using a trained artificial intelligence (AI) model to identify the principal factors affecting PDX engraftment.ResultsMultivariate logistic regression analyses demonstrated that several factors, including a high Ki-67 labeling index (Ki-67LI) (p < 0.001), younger age at diagnosis (p = 0.032), post neoadjuvant chemotherapy (NAC) (p = 0.006), higher histologic grade (p = 0.039), larger tumor size (p = 0.029), and AI-assessed higher intratumoral necrosis (p = 0.027) and intratumoral invasive carcinoma (p = 0.040) proportions, were significant factors for successful PDX engraftment (area under the curve [AUC] 0.905). In the NAC group, a higher Ki-67LI (p < 0.001), lower Miller-Payne grade (p < 0.001), and reduced proportion of intratumoral normal breast glands as assessed by AI (p = 0.06) collectively provided excellent prediction accuracy for successful PDX engraftment (AUC 0.89).ConclusionsWe found that high Ki-67LI, younger age, post-NAC status, higher histologic grade, larger tumor size, and specific morphological attributes were significant factors for predicting successful PDX engraftment of primary breast cancer.

Evaluation of Ki-67, goblet cell and MUC2 mucin RNA expression in dogs with lymphoplasmacytic and granulomatous colitis

Intestinal mucus barrier disruption may occur with chronic inflammatory enteropathies. The lack of studies evaluating mucus health in dogs with chronic colitis arises from inherent challenges with assessment of the intestinal mucus layer. It is therefore unknown if reduced goblet cell (GBC) numbers and/or mucin 2 (MUC2) expression, which are responsible for mucus production and secretion, correlate with inflammation severity in dogs with granulomatous colitis (GC) or lymphocytic-plasmacytic colitis (LPC). It is undetermined if Ki-67 immunoreactivity, which has been evaluated in dogs with small intestinal inflammation, similarly correlates to histologic severity in GC and LPC. Study objectives included comparing Ki-67 immunoreactivity, GBC population and MUC2 expression in dogs with GC, LPC and non-inflamed colon; and exploring the use of ribonucleic acid (RNAscope®) in-situ hybridization (ISH) to evaluate MUC2 expression in canine colon. Formalin-fixed endoscopic colonic biopsies were obtained from 48 dogs over an eight-year period. A blinded pathologist reviewed all biopsies. Dogs were classified into the GC (n=19), LPC (n=19) or no colitis (NC) (n=10) group based on final histopathological diagnosis. Ki-67 immunohistochemistry, Alcian-Blue/PAS staining to highlight GBCs, and RNAscope® ISH using customized canine MUC2-targeted probes were performed. At least five microscopic fields per dog were selected to measure Ki-67 labelling index (KI67%), GBC staining percentage (GBC%) and MUC2 expression (MUC2%) using image analysis software. Spearman’s correlation coefficients were used to determine associations between World Small Animal Veterinary Association histologic score (WHS) and measured variables. Linear regression models were used to compare relationships between WHS with KI67%, GBC%, and MUC2%; and between GBC% and MUC2%. Median WHS was highest in dogs with GC. Median KI67% normalised to WHS was highest in the NC group (6.69%; range, 1.70–23.60%). Median GBC% did not correlate with colonic inflammation overall. Median MUC2% normalised to WHS in the NC group (10.02%; range, 3.05–39.09%) was two- and three-fold higher than in the GC and LPC groups respectively. With increased colonic inflammation, despite minimal changes in GBC% overall, MUC2 expression markedly declined in the LPC group (-27.4%; 95%-CI, −49.8, 5.9%) and mildly declined in the GC and NC groups. Granulomatous colitis and LPC likely involve different pathways regulating MUC2 expression. Decreased MUC2 gene expression is observed in dogs with chronic colitis compared to dogs without colonic signs. Changes in MUC2 expression appear influenced by GBC activity rather than quantity in GC and LPC.

Malignant potential of neuroendocrine microtumor of the pancreas harboring high-grade transformation: lesson learned from a patient with von Hippel-Lindau syndrome.

Pancreatic neuroendocrine microtumor (PNEMT) is a neuroendocrine tumor (NET) < 0.5 cm in diameter, and it is considered benign. We report a PNEMT with high-grade transformation (HGT). A man in his 60s with von Hippel-Lindau syndrome underwent surgical resection of a NET. A second sub-centimeter nodule with a nodule-in-nodule pattern was discovered. The 0.4 cm outer nodule contained clear columnar cells with round nuclei and indistinct nucleoli, while the 0.1 cm inner nodule had eosinophilic cells with an increased nuclear to cytoplasmic ratio, vesicular nuclei, and prominent nucleoli. Tumor cells in the outer and inner nodules were synaptophysin and chromogranin positive. Only the inner nodule was p53 positive, while the outer nodule was exclusively positive for carbonic anhydrase 9 and vimentin. The Ki-67 labeling indices for the outer and inner nodules were 2.1% (grade 1) and 44.3% (grade 3), respectively. This nodule was determined to be a PNEMT with HGT. Our findings suggest that a PNEMT may not always be benign and can undergo HGT.

Evaluating the mode of action of perfluorooctanoic acid-induced liver tumors in male Sprague-Dawley rats using a toxicogenomic approach

The mode of action (MOA) underlying perfluorooctanoic acid (PFOA)-induced liver tumors in rats is proposed to involve peroxisome proliferator-activated receptor α (PPARα) agonism. Despite clear PPARα activation evidence in rodent livers, the mechanisms driving cell growth remain elusive. Herein, we used dose-responsive apical endpoints and transcriptomic data to examine the proposed MOA. Male Sprague-Dawley rats were treated with 0, 1, 5, and 15 mg/kg PFOA for 7, 14, and 28 days via oral gavage. We showed PFOA induced hepatomegaly along with hepatocellular hypertrophy in rats. PPARα was activated in a dose-dependent manner. Toxicogenomic analysis revealed six early biomarkers (Cyp4a1, Nr1d1, Acot1, Acot2, Ehhadh, and Vnn1) in response to PPARα activation. A transient rise in hepatocellular DNA synthesis was demonstrated while Ki-67 labeling index showed no change. Transcriptomic analysis indicated no significant enrichment in pathways related to DNA synthesis, apoptosis, or the cell cycle. Key cyclins including Ccnd1, Ccnb1, Ccna2, and Ccne2 were dose-dependently suppressed by PFOA. Oxidative stress and the nuclear factor-κB signaling pathway were unaffected. Overall, evidence for PFOA-induced hepatocellular proliferation was transient within the studied timeframe. Our findings underscore the importance of considering inter-species differences and chemical-specific effects when evaluating the carcinogenic risk of PFOA in humans.

Pulmonary gangliocytic paraganglioma: An under-recognized mimic of carcinoid tumor

Gangliocytic paragangliomas are rare neoplasms occurring almost exclusively in the ampullary region of the gastrointestinal tract. Although these tumors are not typically considered in the differential diagnosis of primary pulmonary neoplasia, 5 cases of primary pulmonary gangliocytic paragangliomas have been previously reported. Herein we report our experience with 3 additional examples, all referred to our Anatomic Pathology Consultation service. The patients (a 32-year-old man, a 69-year-old woman and a 55-year-old man) each presented with an endobronchial (2 cases) or upper lobe lung mass, ranging from 1.5 to 2.5 cm in maximum dimension. Biopsy and endobronchial debulking specimens demonstrated the classic triphasic morphology of gangliocytic paraganglioma, with epithelial, spindled and ganglion-like cells. By immunohistochemistry, the tumors were positive for keratin, synaptophysin and chromogranin A in the epithelial component, S100 protein and glial fibrillary acidic protein (GFAP) in the Schwannian spindled cells, and synaptophysin in ganglion cells. TTF1 expression was seen in the epithelial components of 2 cases. The Ki-67 labelling index was low (<2%). Primary pulmonary gangliocytic paragangliomas should be distinguished from carcinoid tumors, given the different natural histories and risk stratification approaches for these morphologically similar tumors. Awareness that gangliocytic paraganglioma may occur in the lung and appropriate immunohistochemical studies are key to correct diagnosis.

Prognostic evaluation of the Ki-67 labeling system in histological grading of non-small round cell sarcoma: a supplementary analysis of a randomized controlled trial, JCOG1306.

Soft tissue sarcoma (STS) has various histological types and is rare, making it difficult to evaluate the malignancy of each histological type. Thus, comprehensive histological grading is most important in the pathological examination of STS. The Fédération Nationale des Centres de Lutte Contre le Cancer (FNCLCC) grading system is most commonly used in daily pathological analysis of STS. Among the FNCLCC grading system parameters, mitotic count is a key morphological parameter reflecting the proliferative activity of tumor cells, although its reproducibility may be lacking. Here, we compared the prognostic utility of the conventional and modified FNCLCC grading systems in JCOG1306. We analyzed 140 patients with non-small round cell sarcoma. We performed Ki-67 immunostaining using open biopsy specimens before preoperative chemotherapy in all patients. We assessed histological grade in individual cases by conventional FNCLCC grading (tumor differentiation, mitotic count, and necrosis) and modified FNCLCC grading using the Ki-67 labeling index instead of mitotic count. We conducted univariable and multivariable Cox regression analyses to investigate the influence of grade on overall survival. In univariable analysis, prognosis was worse for patients with conventional FNCLCC Grade 3 tumors compared with Grade 1 or 2 tumors (hazard ratio [HR] 4.21, 95% confidence interval [CI] 1.47-12.05, P=0.008). Moreover, prognosis was worse in patients with modified FNCLCC Grade 3 tumors compared with Grade 1 or 2 tumors (HR 4.90, 95% CI 1.64-14.65, P=0.004). In multivariable analysis including both conventional and modified FNCLCC grading, the modified grading more strongly affected overall survival (HR 6.70, 95% CI 1.58-28.40, P=0.010). The modified FNCLCC grading system was superior to the conventional system in predicting the prognosis of patients with non-small round cell sarcoma according to this supplementary analysis of data from the randomized controlled trial JCOG1306.

Ki-67 labeling index predicts tumor progression patterns and survival in patients with atypical meningiomas following stereotactic radiosurgery

PurposeThis study investigated whether Ki-67 labeling index (LI) correlated with clinical outcomes after SRS for atypical meningiomas.MethodsThis retrospective study examined 39 patients with atypical meningiomas who underwent SRS over a 10-year study period. Ki-67 LI was categorized into 3 groups: low (< 5%), intermediate (5%–10%), and high (> 10%). Local tumor control rates (LCRs), progression-free rates (PFRs), disease-specific survival (DSS) rates, and adverse radiation-induced events (AREs) were evaluated.ResultsThe median follow-up periods were 26 months. SRS was performed at a median prescription dose of 18 Gy for tumors with a median Ki-67 LI of 9.6%. The 3-year LCRs were 100%, 74%, and 25% in the low, intermediate, and high LI groups, respectively (p = 0.011). The 3-year PFRs were 100%, 40%, and 0% in the low, intermediate, and high LI groups (p = 0.003). The 5-year DSS rates were 100%, 89%, and 50% in the low, intermediate, and high LI groups (p = 0.019). Multivariable Cox proportional hazard analysis showed a significant correlation of high LI with lower LCR (hazard ratio [HR], 3.92; 95% confidence interval [CI] 1.18–13.04, p = 0.026), lower PFR (HR 3.80; 95% CI 1.46–9.88, p = 0.006), and shorter DSS (HR 6.55; 95% CI 1.19–35.95, p = 0.031) compared with intermediate LI. The ARE rates were minimal (8%) in the entire group.ConclusionPatients with high Ki-67 LI showed significantly more tumor progression and tumor-related death. Ki-67 LI might offer valuable predictive insights for the post-SRS management of atypical meningiomas.

Prognostic Significance of Tumor-Infiltrating Lymphocytes and High-Risk Human Papillomavirus in Ocular Sebaceous Carcinoma: A Comprehensive Analysis

High-risk human papillomavirus (hrHPV) and tumor-infiltrating lymphocytes (TILs) are known to have prognostic significance in oropharyngeal squamous cell carcinoma. However, their significance in ocular sebaceous carcinoma (OSC) remains unverified because of the rarity of the condition. This study aimed to investigate the association between clinicopathologic features, biomarkers, and hrHPV infection and their potential to predict prognosis in OSC patients. We analyzed the clinicopathologic features of 81 OSC patients from Asan Medical Center between 2000 and 2022. Seventeen biomarkers and hrHPV were examined using immunohistochemistry and DNA in situ hybridization on tissue microarray cores. hrHPV was identified in 31 cases (38.3%). Univariate analysis revealed that hrHPV infection was associated with comedonecrosis (P = .032), high Ki-67 labeling index (≥30%, P = .042), lower expression of E-cadherin (P = .033), and loss of expression of zinc finger protein 750 (P = .023). Multivariate analysis revealed that loss of expression of zinc finger protein 750 (P = .026) remained an independently associated factor for hrHPV. Progression-free survival analysis was performed on 28 patients who were continuously observed for more than 5 years. During a median follow-up duration of 86 months, recurrence or metastasis developed in 14 patients (50%) within the survival cohort, occurring at a median time of 48 months after excision. Univariate analysis indicated that recurrence or metastasis was associated with tumor size (P = .010), high TILs (≥10%; P = .025), lymphovascular invasion (P = 0.043), site of origin (P = .025), and high expression of bcl-2-associated athanogene 3 (P = .039). Multivariate analysis demonstrated that high TILs (P = .017) and site of origin (P = .025) were independent prognostic factors. The prognosis of OSC was hrHPV-independent, and a better prognosis was associated with the site of origin in the order of the gland of Zeis, meibomian gland, and multicentric site, as well as with high TILs.