Pimecrolimus  important to adopt a multidisciplinary approach, with testing performed in laboratories with training and experience in HER2 testing for gastric cancer.The extensive experience of HER2 testing in breast cancer has highlighted the importance of optimizing HER2 testing and interpretation to ensure that patients who may derive benefit receive appropriate targeted therapy. Gastric cancer exhibits unique immunostaining characteristics compared with breast cancer, including the high incidence of tumor heterogeneity in up to 30% of HER2-positive cases.Another key difference from breast cancer staining is that HER2-positive gastric carcinomas are usually of the gland-forming intestinal type and may show incomplete, basolateral, or lateral staining in addition to complete membrane staining and all these are considered as a positive result with immunohistochemistry.

These differences have been taken into account when devising the optimal HER2 testing Vinflunine protocol for gastric cancer and the protocols have been further developed, standardized, and refined in testing and, posttrastuzumab for GAstric cancer, further recommendations have been proposed to ensure quality HER2 testing based on testing data and expert opinion.In order to ensure accurate and reproducible HER2 testing results, it is essential that interpretation of HER2 results is performed with strict adherence to the scoring criteria specific for gastric cancer as reported in the trastuzumab for GAstric cancer study and the recommendations of the expert panel; scoring criteria have been developed and published.Applying the breast cancer testing principles and scoring criteria to HER2 scoring in patients with gastric cancer may result in the underscoring of tumors, and recent evidence suggests that the rate of false-negatives observed may be as high as 50% compared with the trastuzumab for GAstric cancer trial, thus preventing eligible purchase nebivolol patients having access to trastuzumab therapy.

See Table 2 for a comparison of breast and gastric cancer scoring according to the American Society of Clinical Oncology/College of American Pathologists and the European Medicines Agency recommendations.The following sections will provide the most upto- date practical guidance on how to conduct HER2 testing in gastric cancer, from initial sample collection through to scoring the results, and how to ensure quality testing through quality assurance schemes.Although the American Society of Clinical order nebivolol Oncology/ College of American Pathologists recommendations for breast cancer form a solid basis for HER2 testing in gastric cancer, modifications are required to take into account the unique characteristics of this tumor type.

Both surgical specimens and biopsy samples are acceptable for HER2 testing in gastric cancer and the availability of specimen type may vary according to region: for example, surgical specimens are more common in Japan.On the basis of more standardized vasculature fixation conditions, it is generally agreed that biopsies are preferred to ensure optimal testing results. A representative block of the cancer, including the intestinal tumor part, should be taken from surgical specimens and when biopsies are taken, adequate numbers of viable endoscopic biopsies (ideally six to eight) of the cancer are recommended.