HER2状态在乳腺癌穿刺活检和手术切除标本间的表达差异分析OA

Objective To investigate the incidence and potential causes of discrepancies in HER2 status be-tween core needle biopsy(CNB)and surgical excision(SE)specimens of breast cancer,and to explore strategies to re-duce variability in laboratory testing and interpretation.Methods A total of 825 paired CNB and SE specimens from the same breast cancer patients were collected.HER2 immunohistochemical staining was performed.The incidence and patterns of discordant HER2 expression were analyzed.Clinicopathological characteristics were evaluated,and relevant literature was reviewed.Results Among the 825 breast cancer cases,HER2 status discrepancies between CNB and SE specimens were identified in 273 cases(33.09%),of which low-expression cases accounted for 60.81%.After slide review by breast pathologists,70 CNB cases(25.64%)and 62 SE cases(22.71%)were incon-sistent with the original reports,with a significantly lower nonconformity rate observed in SE specimens than in CNB specimens(P<0.05).After excluding interpretation-related factors,the overall discrepancy rate was 23.27%(192/825),and low-expression cases accounted for 63.54%.HER2 discordance was associated with pTNM stage and pro-gesterone receptor(PR)positivity in both univariate and multivariate analyses(P<0.05).Among the 192 discordant cases,tumor heterogeneity was observed in 22 cases(8.06%),varying degrees of inadequate fixation in 28 cases(10.26%),weak staining of the external low-expression control in 18 cases(6.59%),and prior neoadjuvant therapy in 35 cases(12.82%).Interobserver reproducibility analysis showed high agreement among breast pathologists(Kappa=0.743),low agreement between non-specialist and breast pathologists(Kappa=0.213),and moderate agreement among non-specialist pathologists(Kappa=0.651).Conclusion Discrepancies in HER2 status were ob-served between CNB and SE specimens from the same breast cancer patients.Pathological evaluation should take into account tumor heterogeneity,pre-analytical tissue handling,laboratory procedures,neoadjuvant therapy,distinctions between immunohistochemical scores of 0 and 1+,and the experience level of pathologists.