ERBB2 and gastric cancer: In assessment of the HER2 status of gastric cancer biopsies, the concordance rate of diagnosis between biopsy and surgical specimens was reported to be over 70 %.25,26 In this study, the concordance of Rad51-positive staining was 86.7 %, suggesting that Rad51 IHC results in biopsy specimens are useful as a predictive tool of Rad51-positive staining in surgical specimens, similar to the usefulness of HER2 status in biopsies of gastric cancer specimens.