Can we detect and monitor bladder cancer with a urine test? For many patients with bladder cancer (BC), their cancer comes back after treatment and so they have to be regularly checked. These patients are checked with a cystoscope. The camera shows the inside of the bladder and the doctor can make a diagnosis. This method of diagnosis (cystoscopy) can be uncomfortable for the patient and is expensive to the NHS. In collaboration with Paraytec Ltd, we have developed a novel, proprietary technique called ‘Fluid Flow Cell Imaging’ (FFCI) for the rapid analysis of cells in flow, exploiting their intrinsic absorbance, as well as chromic stains. We hope to be able to tell the difference between tumour cells, normal cells and blood cells and reduce the number of cystoscopies that patients need in future.
The technique, a form of flow cytometry, has similarities to FACS analysis but is not dependent on the expression of particular antigens by the cells. Moreover, it is ‘mass parallel’ and has a throughput that is potentially a lot greater than FACS which requires cells to pass in single file past a detector. An additional dimension of cell morphology data is recorded, allowing properties to be ascribed to named individual cells, and ‘censorship’ such that pairs or clumps of cells may be included or eliminated from the analysis.
The lack of requirement for antibodies in cancer screening is a strong advantage of FFCI because cancer cells are notoriously heterogeneous with respect to the surface antigens they express, and are often indistinguishable from healthy cells in FACS analysis because they lack the antigen(s) in question.
We are developing FFCI for the detection of cancer cells in body fluids, such as for the detection of bladder cancer using urine samples. Our mission is to devise a simple test (either as a stand-alone test or in conjunction with filter isolation using our Cellexia filters) that is cheap enough to be used in population screening of high risk individuals, as well as for monitoring of existing cancers such as bladder cancer, and also applicable to other cancers based on blood screening. Fluid Flow Cell-Imaging (even in conjunction with chromic stains) is non-destructive, providing the option of post-hoc analysis of isolated cells by molecular techniques such as PCR, RTPCR, genomics and RNAseq and single cell technologies.
The technique creates a permanent digital record that can be reviewed by cytopathologists or researchers. Unlike classical cytopathology, which is inherently subjective, FFCI is objective (machine read) and ‘indefatigable’ unlike human observers. Moreover it has the capacity to analyse many more cells than could be viewed by traditional microscopy, avoiding missing rare cancer cells.
FFCI takes advantage of astronomical algorithms that were initially developed to detect faint objects on the edge of the known Universe. While the capability to measure the absorbance of cells has existed for many decades, the development of FFCI has awaited the advent of these new enabling algorithms, bespoke hardware development, and the creativity to apply them to cancer diagnosis. The algorithms are able to distinguish cancer cell images from other constituents in blood and urine. This automated process means that there is little time involved in sample preparation and minimal time spent on analysis. Even the letter from GP to patient will be generated automatically, or optionally after review of the video footage by a cytopathologist.
While the basic technique is label-free, the use of labels (chromic stains) in Fluid-Flow Cell-Imaging adds a further dimension of utility, whereby the cancerous phenotype can be identified. While FFCI is most straightforwardly applied to cancer specimens where there are isolated cells or groups of cells (tumour cells in blood and urine), we anticipate that it can likewise be applied to solid biopsies following digestion of a biopsy to create a cell suspension.