Peer-to-peer validation of Ki-67 scoring in a pathology quality circle as a tool to assess interobserver variability: are we better than we thought?

Ki-67, a nuclear protein expressed in all stages of cellular proliferation, is a valuable tool to assess tumor proliferation and has been linked to more aggressive tumor behavior. However, interlaboratory staining heterogeneity and inter-observer variability challenge its reproducibility. Round Robin tests are a suitable tool to standardize and harmonize immunohistochemical and molecular analyses in histopathology. The study investigates the interrater and interlaboratory reproducibility of Ki-67-scoring using both manual and automated approaches. Unstained TMA slides comprising diverse tumor types (breast cancer, neuroendocrine tumors, lymphomas, and head and neck squamous cell carcinoma) were distributed to six pathology laboratories, each employing their routine staining protocols. Manual and automated scoring methods were applied, and interrater and interlaboratory agreement assessed using intraclass correlation coefficients (ICC). The results highlight good-to-excellent reliability overall, with automated scoring demonstrating higher consistency (ICC 0.955) than manual scoring (ICC 0.871). Results were more variable when looking at the individual entities. Reliability remained good for lymphomas (ICC 0.878) and breast cancer (ICC 0.784) and was poor in well-differentiated neuroendocrine tumors (ICC 0.354). This study clearly advocates standardized practices and training to ensure consistency in Ki-67-assessment, and it demonstrates that this can be achieved in a peer-to-peer approach in local quality-circles.

Case report: Ipilimumab and nivolumab in metastatic adrenocortical cancer with high tumor mutational burden.

In the setting of metastatic adrenocortical cancer, there are limited therapy options such as mitotane and platinum-based chemotherapy with only low response rates. Ipilimumab and nivolumab are approved for several solid cancer types. Tumor mutational burden is one established marker to predict treatment success of immunotherapy and has been associated with improved response rates to immune checkpoint inhibitors. We here present the case of a 68-year-old woman with metastatic adrenocortical cancer and high tumor mutational burden treated with ipilimumab and nivolumab in a fourth-line setting. She showed a stable disease for at least 48 weeks, which is significantly longer than the treatment response to mitotane or platinum-based chemotherapy. To the best of our knowledge, this is the first successful use of a long-term two-drug immunotherapy (48 weeks) in a patient with metastatic adrenocortical cancer and high mutational burden. Ipilimumab and nivolumab should be considered as a new therapy option in this patient group.

Nectin-4 is widely expressed in head and neck squamous cell carcinoma.

PURPOSE: Nectin-4 has been successfully established as a target molecule in locally advanced and metastatic bladder cancer. An antibody-drug conjugate (enfortumab-vedotin) directed against nectin-4 has shown marked tumor remission rates in this tumor type, which is known for high expression rates of nectin-4. As head and neck cancer and urothelial carcinomas share morphological and molecular similarities, we aimed to evaluate Nectin-4 expression in head and neck squamous cell carcinoma (HNSCC). MATERIAL AND METHODS: A previously described and clinically characterized cohort of HNSCC (n = 159) was analyzed by immunohistochemistry for Nectin-4 expression. The expression data was correlated to clinico-pathological parameters including patient outcome. RESULTS: Nectin-4 was found in 86.2% of HNSCC, with medium/high expression seen in 32.7% of cases. Non smokers and p16 positive HNSCC showed a higher expression of Nectin-4 (p < 0.005). There was no correlation of Nectin-4 with grading or tumor stage. Nectin-4 positive tumors showed a significant better survival (log rank p = 0.006). CONCLUSIONS: Similar to urothelial carcinoma, Nectin-4 is found in the majority of HNSCC, which clearly warrants further studies to clarify if HNSCC also respond to targeted therapy with enfortumab-vedotin. Moreover, expression of Nectin-4 is associated with HPV infection and may serve as a prognostic marker in HNSCC.

Diagnostic and Therapeutic Approach in a Metastatic Vaginal Adenocarcinoma: A Case Report.

Background: Vaginal adenocarcinomas (VAC) are most often reported after intrauterine exposition to diethylstilbestrol (DES). Rarely, VACs are reported as a malignant transformation of vaginal adenosis or endometriosis, in the context of chromosomal abnormalities or malformations of the uterus or the vagina. VACs without DES exposition have a poor prognosis and a significantly worse outcome compared to vaginal squamous cell carcinomas or DES-associated VACs. Objective: Here, we report the case of a primarily metastatic VAC, treated successfully with different lines of chemo-, antiangiogenic, antibody, and immunotherapy. Case: The 49-year-old patient presented in 5/2018 with a primarily pulmonary metastatic VAC. Significant tumor reduction was seen after six cycles of carboplatin AUC5/paclitaxel 175 mg/m²/bevacizumab 15 mg/kg q3w. Bevacizumab maintenance therapy and later cisplatin mono 50 mg/m² q2w led to local and distant tumor progression. To identify a potential targeted therapy, new tumor biopsies were obtained. Immunohistochemistry revealed ERBB2 expression, and paclitaxel 80 mg/m² weekly plus trastuzumab 4 mg/m² respectively 2 mg/m² q3w was administered. Due to local and pulmonal tumor progression after 6 months and persistent ERBB2 positivity, the therapy was adjusted to trastuzumab emtansine (T-DM1) 3.6 mg/kg q3w; however, the patient remained locally progressive after three cycles of T-DM1 and additionally showed a new bone metastasis. The new tumor biopsies revealed a combined positive score (CPS) of 2 regarding PD-L1, and pembrolizumab 200 mg q3w was initiated. The bone metastasis was radiated and treated with denosumab 120 mg q4w. Extreme tumor regression followed by stable disease was maintained for 9 months. Due to a slow locoregional progress only with new inguinal lymph node and pararectal lymph node metastases, a new tumor biopsy was taken. Molecular profiling showed an ARID1A mutation, a mutational burden of 5.1 mutations per megabase, and no genfusions. Based on these findings, therapy with PD-L1 antibodies, PD-1 antibodies, gemcitabine, or dasatinib was suggested. Therefore, administration of pembrolizumab was continued and local radiation therapy was performed. This led to a decrease in local tumor manifestations and a stable systemic disease. Conclusion: Our case demonstrates the diagnostic and therapeutic approach in a patient with primary metastatic vaginal adenocarcinoma. By tumorgenetic profiling, different lines of systemic therapy, namely, antiangiogenic therapy, monoclonal antibody therapy, immunotherapy, and local radiation therapy, were identified and successfully administered.

Hereditary Diffuse Gastric Cancer: A Comparative Cohort Study According to Pathogenic Variant Status.

Hereditary diffuse gastric cancer (HDGC) is an inherited cancer susceptibility syndrome characterized by an elevated risk for diffuse gastric cancer (DGC) and lobular breast cancer (LBC). Some patients fulfilling the clinical testing criteria harbor a pathogenic CDH1 or CTNNA1 germline variant. However, the underlying mechanism for around 80% of the patients with a family or personal history of DGC and LBC has so far not been elucidated. In this cohort study, patients meeting the 2015 HDGC clinical testing criteria were included, and subsequently, CDH1 sequencing was performed. Of the 207 patients (161 families) in this study, we detected 21 pathogenic or likely pathogenic CDH1 variants (PV) in 60 patients (28 families) and one CTNNA1 PV in two patients from one family. Sixty-eight percent (n = 141) of patients were female. The overall PV detection rate was 18% (29/161 families). Criterion 1 and 3 of the 2015 HDGC testing criteria yielded the highest detection rate of CDH1/CTNNA1 PVs (21% and 28%). PV carriers and patients without proven PV were compared. Risk of gastric cancer (GC) (38/62 61% vs. 102/140 73%) and age at diagnosis (40 ± 13 years vs. 44 ± 12 years) were similar between the two groups. However, GC was more advanced in gastrectomy specimens of patients without PV (81% vs. 26%). LBC prevalence in female carriers of a PV was 20% (n = 8/40). Clinical phenotypes differed strongly between families with the same PV. Emphasis should be on detecting more causative genes predisposing for HDGC and improve the management of patients without a proven pathogenic germline variant.

A case series of cementless revision total knee arthroplasty in patients with benzoyl peroxide allergy.

PURPOSE: The contact allergens nickel, cobalt, and chromium are often discussed as possible triggers of allergic reactions to orthopedic implants. Additionally, acrylates and polymerization additives in bone cement (e.g., benzoyl peroxide (BPO)) have been implicated as triggers of eczema, wound healing disorders, and aseptic implant loosening. We report about six patients with aseptic loosening after total knee arthroplasty (TKA), who underwent revision surgery after testing positive for BPO hypersensitivity. METHODS: After clarification of possible other causes of implant failure, epicutaneous testing had been performed and the implants were replaced in a two-stage procedure with cementless, diaphyseal anchoring, hypoallergenic (TiNb-coated) revision endoprostheses. RESULTS: Epicutaneous testing revealed a BPO allergy in all six patients and an additional nickel allergy in three of the six patients. There was no histopathological or microbiological evidence for a periprosthetic infection. The clinical follow-up showed a low level of pain with good function, a stable knee joint, and proper implant position. The Knee Society Score (KSS) with its subscales Knee Score and Functional Score improved post-operatively from 43 to 70 points and from 47.5 to 68.3 points, respectively. Two implant-specific complications occurred: femoral stress shielding two years post-operatively with no further need for action and aseptic loosening of the tibial stem with the need of revision three years post-operatively. CONCLUSIONS: The regression of complaints after replacement with cementless and nickel-free revision implants suggests allergic implant intolerance. Implantation of a cementless, hypoallergenic endoprosthesis might, therefore, be a surgical treatment strategy in patients with evidence of allergies.