RESUMO
The expression of human epidermal growth factor receptor 2 (HER2) protein or gene transcripts is critical for therapeutic decision making in breast cancer. We examined the performance of a digitalized and artificial intelligence (AI)-assisted workflow for HER2 status determination in accordance with the American Society of Clinical Oncology (ASCO)/College of Pathologists (CAP) guidelines. Our preliminary cohort consisted of 495 primary breast carcinomas, and our study cohort included 67 primary breast carcinomas and 30 metastatic deposits, which were evaluated for HER2 status by immunohistochemistry (IHC) and in situ hybridization (ISH). Three practicing breast pathologists independently assessed and scored slides, building the ground truth. Following a washout period, pathologists were provided with the results of the AI digital image analysis (DIA) and asked to reassess the slides. Both rounds of assessment from the pathologists were compared to the AI results and ground truth for each slide. We observed an overall HER2 positivity rate of 15% in our study cohort. Moderate agreement (Cohen's κ 0.59) was observed between the ground truth and AI on IHC, with most discrepancies occurring between 0 and 1+ scores. Inter-observer agreement amongst pathologists was substantial (Fleiss´ κ 0.77) and pathologists' agreement with AI scores was 80.6%. Substantial agreement of the AI with the ground truth (Cohen´s κ 0.80) was detected on ISH-stained slides, and the accuracy of AI was similar for the primary and metastatic tumors. We demonstrated the feasibility of a combined HER2 IHC and ISH AI workflow, with a Cohen's κ of 0.94 when assessed in accordance with the ASCO/CAP recommendations.
RESUMO
Malignant peritoneal mesothelioma is a rare disease. Patients mainly present with abdominal distension, pain, nausea, and weight loss with or without an exposure history of asbestos. Diagnosis may be difficult from a clinical and histopathologic perspective. Treatment options are surgery in early stages, radiotherapy and/or intraperitoneal or systemic therapy. Prognosis depends on TNM stage and histologic subtype with epithelioid subtype being the most favorable one but in general remains poor. We present a 59-year-old male (patient 1) and a 79-year-old female (patient 2) with progressive dyspnea. PET-CT of patient 1 revealed metastatic spread in the pleura and extensive peritoneal carcinomatosis. PET-CT of patient 2 displayed FDG-avid lymph nodes on both sides of the diaphragm, polyserositis, and FDG uptake along the peritoneum. Both patients were eventually diagnosed with malignant peritoneal mesothelioma. Patient 1 was treated with carboplatin and gemcitabine, and patient 2 received no systemic therapy. Even though the epithelioid subtype was found, both patients succumbed due to rapid tumor progression in a matter of a few weeks only. Presentation with polyserositis even in the absence of relevant asbestos exposure may represent malignant peritoneal mesothelioma if ascites is present, and rapid invasive diagnostic (excision biopsy) should be performed. These two unusual cases emphasize that even in epithelioid subtype, clinicians ought to be aware of possible rapid clinical deterioration, and timely diagnosis with initiation of therapy is crucial. Further research is necessary to better understand tumor biology, establish predictive markers, and develop new treatment options.
