摘要目的:探讨2019版中国乳腺癌人表皮生长因子受体2(HER-2)检测指南对浸润性乳腺癌免疫组化(IHC)检测HER-2(++)患者荧光原位杂交(FISH)检测结果判读的影响及其临床意义。方法:选取2019年5—11月郑州大学第一附属医院收治的569例浸润性乳腺癌患者，根据2014版和2019版乳腺癌HER-2检测指南IHC检测结果判读均为HER-2(++)。进一步行HER-2/17号染色体着丝粒(CEP17)双探针FISH检测，分别根据2014版和2019版乳腺癌HER-2检测指南对检测结果进行判读，分析2019版指南对HER-2检测结果判读的影响。结果:根据2014版指南判读，569例患者中，HER-2阳性139例(24.43%)，HER-2阴性363例(63.80%)，不确定67例(11.78%)。根据2019版指南判读，569例患者中，第1组115例(20.21%)，第2组9例(1.58%)，第3组15例(2.64%)，第4组67例(11.78%)，第5组363例(63.80%); HER-2阳性130例(22.85%)，HER-2阴性439例(77.15%)。与2014版指南比较，根据2019版指南判读后HER-2阳性率由24.43%(139/569)降低为22.85%(130/569)，差异无统计学意义( χ2＝0.394， P＝0.577)；HER-2阴性率由63.80%(363/569)增加到77.15%(439/569)，差异有统计学意义( χ2＝24.392， P<0.05)。43例IHC不完整的弱至中等强度细胞膜染色、根据2014版指南判读为HER-2(++)、根据2019版指南判读为HER-2(+)的患者，其FISH检测结果根据2014版指南判读，HER-2阳性1例(2.33%)，不确定6例(13.95%)，HER-2阴性36例(83.72%)；根据2019版指南判读，43例患者均为HER-2阴性。 结论:按照2019版指南判读IHC检测HER-2(++)患者的FISH检测结果，部分患者由根据2014版指南判读的HER-2(++)变为HER-2(+)，使FISH检测的HER-2阳性率出现小幅度降低，HER-2阴性率升高，并消除了FISH检测不确定的结果，为筛选HER-2靶向治疗获益患者提供了更为明确的参考。

abstractsObjective:To investigate the impact and clinical significance of the revised 2019 Chinese HER-2 testing guidelines on the detecting result evaluation of invasive breast cancers with equivocal HER-2 immunostaining by using fluorescence in situ hybridization (FISH).Methods:A total of 569 cases of invasive breast cancers with HER-2 (+ + ) immunostaining evaluated according to the immunohistochemistry (IHC) guidelines of 2014 edition and 2019 edition from May to November 2019 were collected and further detected by FISH. The results of HER-2/CEPl7 double probe were respectively interpreted according to both the 2014 and 2019 Chinese HER-2 testing guidelines and the results were compared.Results:According to the 2014 guidelines, the number of HER-2 positive, equivocal and negative cases were 139 (24.43%), 67 (11.78%), and 363 (63.80%), respectively. Whereas according to the 2019 guidelines, 115 cases (20.21%) were the first group, 9 cases (1.58%) were the second group, 15 cases (2.64%) were the third group, 67 cases (11.78%) were the fourth group, and 363 cases were (63.80%) the fifth group, of which 130 cases (22.85%) were positive and 439 cases (77.15%) were negative by FISH detecting. Compared with the guideline of 2014 edition, the HER-2 positive rate of FISH detection reduced from 24.43% (139/569) to 22.85% (130/559) according to the application of the guideline of 2019 edition, but the difference was not statistically significant ( P=0.567), while the negative rate increased from 63.80% (363/569) to 77.15% (439/569), with a statistically significant difference ( P<0.05). Forty-three cases with incomplete weak to medium intensity of IHC membrane staining which were HER-2 (+ + ) according to 2014 guideline were changed to IHC (+ ) on the basis of the 2019 guideline. According to the FISH guideline of 2014 edition, 1 case (2.33%) was positive, 6 cases (13.95%) was equivocal and 36 cases (83.72%) was negative, while according to the 2019 FISH guideline, all of the 43 cases were negative. Conclusions:According to the guideline of 2019 edition, a proportion of cases changes from HER-2 (+ + ) to (+ ), and the HER-2 positive rate of FISH test decreases slightly, the negative rate increases, the equivocal result is eliminated, which provides a definite reference for screening patients who will be benefited from the targeted treatment of HER-2.