Targeted molecular-genetic imaging and ligand-directed therapy in aggressive variant prostate cancer

Aggressive variant prostate cancers (AVPC) are a clinically defined group of tumors of heterogeneous morphologies, characterized by poor patient survival and for which limited diagnostic and treatment options are currently available. We show that the cell surface 78-kDa glucose-regulated protein (GRP78), a receptor that binds to phage-display-selected ligands, such as the SNTRVAP motif, is a candidate target in AVPC. We report the presence and accessibility of this receptor in clinical specimens from index patients. We also demonstrate that human AVPC cells displaying GRP78 on their surface could be effectively targeted both in vitro and in vivo by SNTRVAP, which also enabled specific delivery of siRNA species to tumor xenografts in mice. Finally, we evaluated ligand-directed strategies based on SNTRVAP-displaying adeno-associated virus/phage (AAVP) particles in mice bearing MDA-PCa-118b, a patient-derived xenograft (PDX) of castration-resistant prostate cancer bone metastasis that we exploited as a model of AVPC. For theranostic (a merging of the terms therapeutic and diagnostic) studies, GRP78-targeting AAVP particles served to deliver the human Herpes simplex virus thymidine kinase type-1 (HSVtk) gene, which has a dual function as a molecular-genetic sensor/reporter and a cell suicide-inducing transgene. We observed specific and simultaneous PET imaging and treatment of tumors in this preclinical model of AVPC. Our findings demonstrate the feasibility of GPR78-targeting, ligand-directed theranostics for translational applications in AVPC

Histologic and Immunohistochemical Decision-Making in Endometrial Adenocarcinoma

Diffuse p53 immunostaining distinguishes 85% of serous (Type II) from endometrioid (Type I) carcinomas and is an independent marker for poor prognosis. Interobserver reproducibility for the diagnosis of these entities, as well as selection and prediction of p53 immunostaining results, is unknown. Reproducibility of three pathologists regarding: (1) a two (I and II) and (2) three part classification (I, II or indeterminate ); (3) recommendation for p53 staining and (4) expectations of p53 staining results were computed with the kappa (k) statistic. All cases were immunostained for p53 and independently scored. A two and three tiered classification scheme achieved high (k=0.71) and moderate (k =0.49) reproducibility. Non-unanimous cases were more likely to be reclassified into an 'indeterminate' category (27 cases, 39% of passes) compared to those with unanimous (82 cases, 14% of passes) classification. Pathologists recommended p53 immunostaining with poor (k=0.28) reproducibility, but staining prediction was made with good concordance ( 69%, k=0.50). Moreover, p53 staining was more common in diagnostically discordant (46%) compared to concordant (16%) cases. A subset of endometrial cancers do not readily fit within a two-class system and can be culled from cases that (1) do not achieve interobserver concordance and (2) are more likely to be chosen for p53 immunostaining and (3) are more likely to stain positive for p53. Because p53 is an important marker for endometrial adenocarcinoma outcome, and cannot be predicted in advance in indeterminate cases, p53 immunostaining should be employed in cases with observer disagreement in a binary system

Squamous Morules Are Functionally Inert Elements of Premalignant Endometrial Neoplasia

Squamous morules are a common component of premalignant glandular lesions that are followed by glandular, rather than squamous, carcinomas. We tested the hypothesis that the appearance of glands associated with morules predicts cancer risk, and undertook molecular testing to determine the clonal and hormonal response properties of admixed squamous and glandular elements. 66 patients with squamous morules in an index endometrial biopsy had followup clinical data (average followup: interval 31 months, 2.5 biopsies) showing development of carcinoma in 11% (7/66) of cases. The histological appearance of morule-associated glands in the index biopsy was significantly associated with this clinical outcome, with the majority (71%, 5/7) of cancer occurrences following an overtly premalignant lesion (Endometrial Intraepithelial Neoplasia) with squamous morules. Eight endometrial intraepithelial neoplasias with squamous morules were examined by immunohistochemistry for estrogen and progesterone receptors and mitotic activity (Ki-67 antigen percent stained). Glandular components had abundant estrogen and progesterone receptors, and high levels of mitotic activity in all cases. In sharp contrast, all squamous morules were devoid of sex hormone receptors and had undetectable or extremely low proliferation rates. When mutated, the same specific PTEN mutation was detected in squamous and glandular elements, indicating that both are of common lineage. The clinical and laboratory data are consistent with a model of morule biology in which squamous morules are a hormonally incompetent subpopulation of endometrial glandular lesions. Isolated morules might result from artifactual displacement from their native glandular context, or selective hormonally induced regression of the glandular but not squamous components over time. Subsequent cancer risk, as promoted by estrogens, is greatest when the glandular component has the appearance of endometrial intraepithelial neoplasia. Even isolated morules should be carefully followed, however, to exclude a coexisting undersampled, or occult, glandular lesion

Quantitative Imaging Analysis Fluorescence In Situ Hybridization Validation for Clinical HER2 Testing in Breast Cancer.

Context.—Quantitative imaging is a promising tool that is gaining wide use across several areas of pathology. Although there has been increasing adoption of morphologic and immunohistochemical analysis, the adoption of evaluation of fluorescence in situ hybridization (FISH) on formalin-fixed, paraffin-embedded tissue has been limited because of complexity and lack of practice guidelines.Objective.—To perform human epidermal growth factor receptor 2 (HER2) FISH validation in breast carcinoma in accordance with the American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) 2018 guideline.Design.—Clinical validation of HER2 FISH was performed using the US Food and Drug Administration-approved dual-probe HER2 IQFISH (Dako, Carpinteria, California) with digital scanning performed on a PathFusion (Applied Spectral Imaging, Carlsbad, California) system. Validation parameters evaluated included z-stacking, classifier, accuracy, precision, software, and hardware settings. Finally, we evaluated the performance of digital enumeration on clinical samples in a real-world setting.Results.—The accuracy samples showed a final concordance of 95.3% to 100% across HER2 groups 1 to 5. During clinical implementation for HER2 groups 2, 3, and 4, we achieved a final concordance of 76% (95 of 125). Of these cases, only 8% (10 of 125) had discordances with clinical impact that could be identified algorithmically and triaged for manual review.Conclusions.—Digital FISH enumeration is a useful tool to improve the efficacy of HER2 FISH enumeration and capture genetic heterogeneity across HER2 signals. Excluding cases with high background or poor image quality and manual review of cases with ASCO/CAP group discordances can further improve the efficiency of digital HER2 FISH enumeration

The next phase in patient safety education: Towards a standardized, tools-based pathology patient safety curriculum: A call to action from the Association of Pathology Chairs' Residency Program Directors Section Training Residents in Patient Safety Workgroup.

Patient safety education is a mandated Common Program Requirement of the Accreditation Council for Graduate Medical Education and for the Royal College of Physicians and Surgeons of Canada in all medical residency and fellowship programs. Although many hospitals and healthcare environments have general patient safety education tools for trainees, few to none focus on the unique training milieu of pathologists, including a mix of highly automated and manual error-prone processes, frequent multiplicity of events, and lack of direct patient relationships for error disclosure. We established a national Association of Pathology Chairs-Program Directors Section Workgroup focused on patient safety education for pathology trainees entitled Training Residents in Patient Safety (TRIPS). TRIPS included diverse representatives from across the United States, as well as representatives from pathology organizations including the American Board of Pathology, the American Society for Clinical Pathology, the United States and Canadian Academy of Pathology, the College of American Pathologists, and the Society to Improve Diagnosis in Medicine. Objectives of the workgroup included developing a standardized patient safety curriculum, designing teaching and assessment tools, and refining them with pilot sites. Here we report the establishment of TRIPS as well as data from national needs assessment of Program Directors across the country, who confirmed the need for a standardized patient safety curriculum