Sjoerd Ligthart, a researcher at the University of Twente’s MIRA research institute, has developed a computer program capable of revealing details of blood pictures in cancer patients. The program counts the circulating tumour cells in a blood sample, and identifies them by type. At the moment, this work is still being carried out by medical specialists. The program can achieve great savings, by lightening these physicians’ workload. Not only that, but the program is faster, cheaper, and less error prone. Furthermore, the clinical pictures that it generates are more extensive than those produced by medical specialists using just the naked eye. Sjoerd Ligthart defended his doctoral thesis at the University of Twente on 10 May.
Cancers spread when tumour cells enter the circulation. Previous research has shown that the higher the number of circulating tumour cells (CTCs), the shorter the patient’s life expectancy. However, it is no easy matter to trace CTCs in the blood. This is because there is no common set of characteristics shared by all of these cells. Also, there are very few of them in the blood - just one CTC to every billion healthy blood cells. If just a few CTCs were to be incorrectly identified or overlooked, this could have major repercussions for the patient in question. It is therefore vital to get a reliable count of any objects that might pose a hazard to the patient.
The blood pictures of patients with tumours are currently assessed by detecting CTCs with iron particles that bind to potentially harmful cells in the blood. A magnetic field then separates these cells from other components of the blood, such as red and white blood cells. The remaining cells are then stained (to improve their contrast), and photographed using a camera mounted on a microscope. In current medical practice, specialists assess the recorded images by eye and count the number of CTCs found. Sjoerd Ligthart’s program has eliminated the need for this procedure. The software selects tumour cells on the basis of certain properties. It then acquires quantitative data on the CTCs, which can be used to identify the specific cancer subtype involved. This collection of quantitative data means that the clinical pictures revealed by the program are more extensive than those currently being reported by medical specialists. Dr Ligthart points out that “This quantitative data makes it possible to produce more reliable estimates of life expectancy and to assess the effectiveness of a given course of therapy.” Not only that, but the program is faster, cheaper, and less error prone than a specialist.
As yet, in everyday practice, circulating tumour cells are not routinely assessed when making a diagnosis. The researcher feels that this situation needs to be rectified. “The counting and identification of CTCs should be included in the guidelines for medical specialists. It should be a standard diagnostic tool.” Dr Ligthart feels that his method could vastly simplify these procedures.
The program has been tested in patients with breast, colorectal, or prostate cancer. Further research is needed to find out whether the program could also be used in other types of cancer. Work is also under way to determine how the program could be integrated into everyday medical practice.
Sjoerd Ligthart carried out his PhD research at the Department of Medical Cell Biophysics (MCBP), part of the University of Twente’s MIRA research institute. His supervisor was Prof. L.W.M.M. Terstappen. The research was conducted in collaboration with Veridex LLC, a subsidiary of Johnson and Johnson.
Note to the press
For further details, or an electronic version of the PhD thesis entitled “Redefining circulating tumor cells by image processing”, please contact the Science Information Officer, Kim Bekmann, +31(0)53-4892131/+31(0)6-22436275.
