Su Yuhua, Goncalves Theodore, Dias-Santagata Dora, Hoang Mai P
From the Department of Pathology, Massachusetts General Hospital and Harvard Medical School, Boston.
Am J Clin Pathol. 2017 Jan 1;147(1):77-82. doi: 10.1093/ajcp/aqw201.
Patients whose tumors harbor ROS1 translocation may benefit from targeted therapy. Detection of ROS1 rearrangement can be done by three methods: immunohistochemistry, fluorescence in situ hybridization, and molecular assays. Immunohistochemistry would be a cost-effective means to screen for ROS1 translocation, which is uncommon.
ROS1 immunostain was performed on cases with known ROS1 translocation status detected either by fluorescence in situ hybridization or next-generation sequencing.
Fifty-seven cases, 10 lung carcinomas with ROS1 rearrangement and 47 cases without ROS1 rearrangement (25 lung carcinomas, 13 gastrointestinal carcinomas, three brain tumors, and six miscellaneous tumors), were included. ROS1 immunostain exhibited 100% sensitivity and 85% specificity, with staining seen in 10 (100%) of 10 cases with ROS1 rearrangement and in seven (15%) of 47 lung cases without ROS1 rearrangement. Weak or 1+ staining of reactive pneumocytes was seen in eight (14%) of 57 cases, and strong staining of osteoclast giant cells was seen in one case.
Since ROS1 rearrangement is an infrequent event, immunohistochemistry is a cost-effective screening method. Confirmation of all positive and equivocal/weak staining with molecular assays would exclude the false-positive cases.
肿瘤携带ROS1易位的患者可能从靶向治疗中获益。ROS1重排的检测可通过三种方法进行：免疫组织化学、荧光原位杂交和分子检测。免疫组织化学将是一种经济有效的筛查ROS1易位的方法，ROS1易位并不常见。
对通过荧光原位杂交或二代测序检测出已知ROS1易位状态的病例进行ROS1免疫染色。
纳入57例病例，其中10例为伴有ROS1重排的肺癌，47例无ROS1重排（25例肺癌、13例胃肠道癌、3例脑肿瘤和6例其他肿瘤）。ROS1免疫染色显示敏感性为100%，特异性为85%，10例伴有ROS1重排的病例中有10例（100%）呈染色阳性，47例无ROS1重排的肺癌病例中有7例（15%）呈染色阳性。57例病例中有8例（14%）可见反应性肺细胞弱阳性或1+染色，1例可见破骨巨细胞强染色。
由于ROS1重排并不常见，免疫组织化学是一种经济有效的筛查方法。对所有阳性和可疑/弱阳性染色结果进行分子检测确认可排除假阳性病例。
