美国科学家研发出一种癌细胞追踪技术，能用一种微型仪器追踪拍摄血液中的癌细胞，从而观察癌症病人在手术后的复原情况。
癌症病人接受手术后，血液中会出现从肿瘤脱落的循环肿瘤细胞（circulating tumor cell）。循环肿瘤细胞就好像肿瘤种子，可以随着血液循环到身体其他部位，发育成新的肿瘤。
通过监督循环肿瘤细胞的数量和踪迹，医生就能提早发现病人会不会再度患上癌症，也能了解化疗或其他治疗是否对病人产生效果。
马萨诸塞州总医院和哈佛医学院的科学家斯托特说：“我们对这种细胞非常有兴趣，因为我们相信这就是能让我们进一步认识癌症生物学和癌症如何转移的细胞。”
斯托特的小组利用一种像生物胶的物质，让微芯片附着在血液中的循环肿瘤细胞上，追踪拍摄循环肿瘤细胞的图像。这种搭配了显微镜头的微芯片能拍摄和储存至少6000张图像。
斯托特说：“无需预先处理，你只须抽出血液，然后将微芯片置入血液里。”她说，有了这个方法，医生不必动手术割开病人身体，就可以监督肿瘤的情况。(生物谷Bioon.com)
生物谷推荐原文出处：
Science TM DOI: 10.1126/scitranslmed.3000403
Isolation and Characterization of Circulating Tumor Cells from Patients with Localized and Metastatic Prostate Cancer
Shannon L. Stott1,2,3,*, Richard J. Lee4,5,*, Sunitha Nagrath1,2,3,*, Min Yu4, David T. Miyamoto4,6, Lindsey Ulkus4, Elizabeth J. Inserra4, Matthew Ulman4, Simeon Springer4, Zev Nakamura4, Alessandra L. Moore1, Dina I. Tsukrov1, Maria E. Kempner4, Douglas M. Dahl2,7, Chin-Lee Wu4,8, A. John Iafrate4,8, Matthew R. Smith4,5, Ronald G. Tompkins2,3, Lecia V. Sequist4,5, Mehmet Toner1,2,3, Daniel A. Haber4,5,? and Shyamala Maheswaran3,4
Rare circulating tumor cells (CTCs) are present in the blood of patients with metastatic epithelial cancers but have been difficult to measure routinely. We report a quantitative automated imaging system for analysis of prostate CTCs, taking advantage of prostate-specific antigen (PSA), a unique prostate tumor–associated marker. The specificity of PSA staining enabled optimization of criteria for baseline image intensity, morphometric measurements, and integration of multiple signals in a three-dimensional microfluidic device. In a pilot analysis, we detected CTCs in prostate cancer patients with localized disease, before surgical tumor removal in 8 of 19 (42%) patients (range, 38 to 222 CTCs per milliliter). For 6 of the 8 patients with preoperative CTCs, a precipitous postoperative decline (<24 hours) suggests a short half-life for CTCs in the blood circulation. Other patients had persistent CTCs for up to 3 months after prostate removal, suggesting early but transient disseminated tumor deposits. In patients with metastatic prostate cancer, CTCs were detected in 23 of 36 (64%) cases (range, 14 to 5000 CTCs per milliliter). In previously untreated patients followed longitudinally, the numbers of CTCs declined after the initiation of effective therapy. The prostate cancer–specific TMPRSS2-ERG fusion was detectable in RNA extracted from CTCs from 9 of 20 (45%) patients with metastatic disease, and dual staining of captured CTCs for PSA and the cell division marker Ki67 indicated a broad range for the proportion of proliferating cells among CTCs. This method for analysis of CTCs will facilitate the application of noninvasive tumor sampling to direct targeted therapies in advanced prostate cancer and warrants the initiation of long-term clinical studies to test the importance of CTCs in invasive localized disease.
