Future clinical role for flow cytometry.

It appears that there is an essential, not just supportive, role for flow cytometry in the clinical context, particularly in providing early information in clinical oncology. High flow rate enumeration and sorting of rare cells, combined with microscopy, offer immediate benefits in the clinical processing of at least some cancers. These benefits would be in diagnosis (perhaps very early detection of metastatic cells in the present prediagnostic phase of solid tumor growth), monitoring, prognosis, and therapy. Importantly, flow cytometric measures can be implemented immediately, and measurement times are short. The value of high flow rate operation of existing facilities in clinical, "supportive" flow cytometry should be better appreciated, if only because shorter measurement times and on-line analysis would make the existing facilities more cost effective: higher throughput for the same overheads. Finally, the wisdom of employing nonsorting cytometers for clinical use should be strongly questioned. Thus, what future impact will the application of flow sorting have in clinical fields old and new, e.g., in bacterial infection measurements in peripheral blood? In particular, nonsorting machines will be unable to adopt the "essential" clinical role I have proposed here.