BackgroundTo improve cancer therapy, it is critical to target metastasizing cells. Circulating tumor cells (CTCs) are rare cells found in the blood of patients with solid tumors and may play a key role in cancer dissemination. Uncovering CTC phenotypes offers a potential avenue to inform treatment. However, CTC transcriptional profiling is limited by leukocyte contamination; an approach to surmount this problem is single cell analysis. Here we demonstrate feasibility of performing high dimensional single CTC profiling, providing early insight into CTC heterogeneity and allowing comparisons to breast cancer cell lines widely used for drug discovery.Methodology/Principal FindingsWe purified CTCs using the MagSweeper, an immunomagnetic enrichment device that isolates live tumor cells from unfractionated blood. CTCs that met stringent criteria for further analysis were obtained from 70% (14/20) of primary and 70% (21/30) of metastatic breast cancer patients; none were captured from patients with non-epithelial cancer (n = 20) or healthy subjects (n = 25). Microfluidic-based single cell transcriptional profiling of 87 cancer-associated and reference genes showed heterogeneity among individual CTCs, separating them into two major subgroups, based on 31 highly expressed genes. In contrast, single cells from seven breast cancer cell lines were tightly clustered together by sample ID and ER status. CTC profiles were distinct from those of cancer cell lines, questioning the suitability of such lines for drug discovery efforts for late stage cancer therapy.Conclusions/SignificanceFor the first time, we directly measured high dimensional gene expression in individual CTCs without the common practice of pooling such cells. Elevated transcript levels of genes associated with metastasis NPTN, S100A4, S100A9, and with epithelial mesenchymal transition: VIM, TGFß1, ZEB2, FOXC1, CXCR4, were striking compared to cell lines. Our findings demonstrate that profiling CTCs on a cell-by-cell basis is possible and may facilitate the application of ‘liquid biopsies’ to better model drug discovery.
Breast cancer outcomes in low-and middle-income countries (LMCs) correlate with the degree to which 1) cancers are detected at early stages, 2) newly detected cancers can be diagnosed correctly, and 3) appropriately selected multimodality treatment can be provided properly in a timely fashion. The Breast Health Global Initiative (BHGI) invited international experts to review and revise previously developed BHGI resource-stratified guideline tables for early detection, diagnosis, treatment, and healthcare systems. Focus groups addressed specific issues in breast pathology, radiation therapy, and management of locally advanced disease. Process metrics were developed based on the priorities established in the guideline stratification. The groups indicated that cancer prevention through health behavior modification could influence breast cancer incidence in LMCs. Diagnosing breast cancer at earlier stages will reduce breast cancer mortality. Programs to promote breast self-awareness and clinical breast examination and resource-adapted mammographic screening are important early detection steps. Breast imaging, initially with ultrasound and, at higher resource levels with diagnostic mammography, improves preoperative diagnostic assessment and permits image-guided needle sampling. Multimodality therapy includes surgery, radiation, and systemic therapies. Government intervention is needed to address drug-delivery problems relating to high cost and poor access. Guideline dissemination and implementation research plays a crucial role in improving care. Adaptation of technology is needed in LMCs, especially for breast imaging, pathology, radiation therapy, and systemic treatment. Curricula for education and trainingThe Breast Health Global Initiative (BHGI) gratefully acknowledges grants and conference support from the following organizations and
Supportive-expressive therapy, with its emphasis on providing support and helping patients face and deal with their disease-related stress, can help reduce distress in patients with metastatic breast cancer.
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