Department of Pathology, The University of Texas MD Anderson Cancer Center Houston, Texas 77030, USA.
Cancer Med. 2013 Apr;2(2):226-33. doi: 10.1002/cam4.70. Epub 2013 Mar 6.
Human epidermal growth factor receptor 2 (HER2) gene amplification in circulating tumor cells (CTCs) and disseminated tumor cells (DTCs) might be useful for modifying Herceptin therapy in breast cancer. In the process of investigating the utility of a microfluidic platform for detecting HER2 gene amplification in these cells, we observed novel results on discordance of HER2 status. Peripheral blood (8.5 mL) and bone marrow (BM) (7.5-10 mL) were collected prospectively from patients with clinical stages I-IV breast cancer. Mononuclear cells were recovered, stained with cytokeratin (CK), CD45, and DAPI, and processed through microfluidic channels for fluorescence in situ hybridization (FISH). A ratio of HER2:CEP17 >2 in any CK+/CD45 or CK-/CD45 cell was regarded as positive for HER2 gene amplification. Peripheral blood from 95 patients and BM from 78 patients were studied. We found CK+/CD45-/DAPI+ CTCs in 27.3% of patients. We evaluated HER2 gene amplification by FISH in 88 blood and 78 BM specimens and found HER2+ CTCs in 1 of 9 (11.1%) and HER2+ DTCs (27.2%) in 3 of 11 patients with HER2+ primary tumor. Among patients with a HER2- primary tumor, 5 of 79 had HER2+ CTCs (6.3%) and 14 of 67 had HER2+ DTCs (20.8%). The overall rate of discordance in HER2 status was 15% between primary tumor and CTCs and 28.2% between primary tumor and DTCs. HER2 was amplified in CTCs and DTCs in a portion of both HER2+ and HER2- primary tumors. HER2 discordance was more frequent for DTCs. The clinical implications of evaluating HER2 status in CTCs and DTCs in breast cancer needs to be established in prospective clinical trials. The cell enrichment and extraction microfluidic technology provides a sensitive platform for evaluation of HER2 gene amplification in CTCs and DTCs.
人类表皮生长因子受体 2 (HER2) 基因扩增在循环肿瘤细胞 (CTC) 和播散性肿瘤细胞 (DTC) 中可能有助于修改曲妥珠单抗治疗乳腺癌。在研究用于检测这些细胞中 HER2 基因扩增的微流控平台的实用性的过程中，我们观察到了 HER2 状态不一致的新结果。前瞻性收集临床分期 I-IV 期乳腺癌患者外周血 (8.5 mL) 和骨髓 (BM) (7.5-10 mL)。回收单核细胞，用细胞角蛋白 (CK)、CD45 和 DAPI 染色，并通过微流控通道进行荧光原位杂交 (FISH)。任何 CK+/CD45 或 CK-/CD45 细胞中 HER2:CEP17 的比值>2 被视为 HER2 基因扩增阳性。研究了 95 例患者的外周血和 78 例患者的 BM，发现 27.3%的患者存在 CK+/CD45-/DAPI+ CTCs。我们用 FISH 评估了 88 份血液和 78 份 BM 标本中的 HER2 基因扩增，发现 11 例 HER2+原发肿瘤中有 1 例存在 HER2+CTC，3 例存在 HER2+DTC (27.2%)。在 HER2-原发肿瘤患者中，79 例中有 5 例 (6.3%)存在 HER2+CTC，67 例中有 14 例 (20.8%)存在 HER2+DTC。HER2 状态在原发肿瘤与 CTC 之间的不一致率为 15%，在原发肿瘤与 DTC 之间的不一致率为 28.2%。HER2 在部分 HER2+和 HER2-原发肿瘤的 CTC 和 DTC 中均有扩增。DTC 的 HER2 不一致更为常见。在乳腺癌中评估 CTC 和 DTC 中的 HER2 状态的临床意义需要在前瞻性临床试验中建立。细胞富集和提取微流控技术为评估 CTC 和 DTC 中的 HER2 基因扩增提供了一种敏感的平台。
