PubMed · 5797882
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A N Broers. 1969. A new high resolution reflection scanning electron microscope.. https://doi.org/10.1063/1.1684146
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BACKGROUND: Therapeutic decisions in cancer are generally guided by molecular biomarkers or, for some newer therapeutics, primary tumor genotype. However, because biomarkers or genotypes may change as new metastases emerge, circulating tumor cells (CTCs) from blood are being investigated for a role in guiding real-time drug selection during disease progression, expecting that CTCs will comprehensively represent the full spectrum of genomic changes in metastases. However, information is limited regarding mutational heterogeneity among CTCs and metastases in breast cancer as discerned by single cell analysis. The presence of disseminated tumor cells (DTCs) in bone marrow also carry prognostic significance in breast cancer, but with variability between CTC and DTC detection. Here we analyze a series of single tumor cells, CTCs, and DTCs for PIK3CA mutations and report CTC and corresponding metastatic genotypes. METHODS: We used the MagSweeper, an immunomagnetic separation device, to capture live single tumor cells from breast cancer patients' primary and metastatic tissues, blood, and bone marrow. Single cells were screened for mutations in exons 9 and 20 of the PIK3CA gene. Captured DTCs grown in cell culture were also sequenced for PIK3CA mutations. RESULTS: Among 242 individual tumor cells isolated from 17 patients and tested for mutations, 48 mutated tumor cells were identified in three patients. Single cell analyses revealed mutational heterogeneity among CTCs and tumor cells in tissues. In a patient followed serially, there was mutational discordance between CTCs, DTCs, and metastases, and among CTCs isolated at different time points. DTCs from this patient propagated in vitro contained a PIK3CA mutation, which was maintained despite morphological changes during 21 days of cell culture. CONCLUSIONS: Single cell analysis of CTCs can demonstrate genotypic heterogeneity, changes over time, and discordance from DTCs and distant metastases. We present a cautionary case showing that CTCs from any single blood draw do not always reflect metastatic genotype, and that CTC and DTC analyses may provide independent clinical information. Isolated DTCs remain viable and can be propagated in culture while maintaining their original mutational status, potentially serving as a future resource for investigating new drug therapies.
BACKGROUND: Routine magnetic resonance imaging (MRI) surveillance of bone marrow change in patients with Gaucher disease (GD) is recommended, but interpretation of imaging findings in the developing skeleton may be difficult. OBJECTIVES: To assess the agreement between routine spinal MRI findings and clinical course in paediatric GD patients receiving enzyme replacement therapy (ERT). MATERIALS AND METHODS: A retrospective institutional review of all GD patients on ERT who had had repeated routine spinal MRI in accordance with national recommendations ( n=14) was carried out. Vertebral body bone marrow MRI T1 signal was assessed relative to intervertebral discs. MRI findings were then compared with recorded date(s) of ERT initiation and possible therapy changes. RESULTS: Nine patients had spinal MRI both before and after the start of ERT. MRI T1 marrow signal was normal in two and abnormal in three of the nine patients both before and after the start of ERT. Two of the nine patients had normalization and one had conversion from normal to abnormal T1 signal. Interpretation was uncertain in one. Seven episodes of treatment intensification occurred. MRI T1 marrow signal was normal before five and uncertain before two of the seven episodes. CONCLUSION: Routine spinal MRI had low accuracy for predicting clinically indicated therapy intensification.
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