Global Study on the Accuracy of Human Epidermal Growth Factor Receptor 2-Low Diagnosis in Breast Cancer.

Context.—: Recently, a new type of antibody-drug conjugate, trastuzumab-deruxtecan (T-DXd), has been approved for the treatment of metastatic breast cancer with low level of human epidermal growth factor receptor 2 (HER2) gene expression. Thereby, eligibility relies on an accurate diagnosis of HER2-low status defined by immunohistochemistry IHC 1+/2+ with no gene amplification.

Global Ring Study to Investigate the Comparability of Total Assay Performance of Commercial Claudin 18 Antibodies for Evaluation in Gastric Cancer.

Claudin 18.2 (CLDN18.2), the dominant isoform of CLDN18 in gastric tissues, is a highly specific tight junction protein of the gastric mucosa with variably retained expressions in gastric and gastroesophageal junction cancers.

Cytogenetic and immunohistochemical characterization of mammary analogue secretory carcinoma of salivary glands.

Objectives: Mammary analogue secretory carcinoma (MASC), initially considered a subset of acinic cell carcinoma (ACC), harbors an ETV6 translocation [t(12:15)(p13:25 q)] and is now regarded as a distinct entity. Several putative markers to differentiate MASC from ACC have been reported; however, the immunohistochemical profile is still being explored and updated. The purpose of this study was to further explore the cytogenetic and immunohistochemical profile of MASC.

Targeting EGFR and PI3K pathways in ovarian cancer.

Background: The epidermal growth factor receptor (EGFR) is expressed in ovarian cancer, but agents targeting this pathway have shown little effect as single agents. This may be due to the presence of alternative pathways, particularly activation of the PI3K/Akt/MTOR pathway.

Methods: We have therefore examined the effect of inhibitors of this pathway (ZSTK474 and sirolimus) in combination with the EGFR inhibitors erlotinib and gefitinib in ovarian cancer primary cell cultures.

Fluorescence in situ hybridisation (FISH) in histologically challenging conjunctival melanocytic lesions.

Background: Even in experienced hands, the classification of some melanocytic lesions of the conjunctiva remains challenging. In skin pathology, the recent application of fluorescence in situ hybridisation (FISH) has been demonstrated to be of use for the analysis and diagnosis of ambiguous melanocytic neoplasms of the skin. This study set out to evaluate this method on seven prospective conjunctival cases that were histologically equivocal.