New device takes the trauma out of cervical cancer screening
A hand-held device originally developed by Sheffield researchers could reduce the time it takes to diagnose cervical cancer from several weeks to a matter of minutes, so improving cancer detection rates and reducing the false alarms caused by smear tests.
The device, known as APX, was originally developed at the University of Sheffield by Brian Brown, Professor of Medical Physics & Clinical Engineering within the Medical School, in collaboration with John Tidy, a consultant Gynaecology Oncologist at the Hallamshire Hospital. Professor Brown's work on electrical impedance tomography, where electrodes are placed onto a part of the body and an image is produced of the impedance distribution in that area, laid the foundations for the revolutionary new device. Professor Brown predicts that the device will ease the trauma of smear-testing for thousands of women.
The breakthrough will be welcome news to the 2,400 women affected by cervical cancer every year in the UK. Currently women over 25 are tested for the cancer with a smear test every three to five years, although many are left with an anxious five week wait to learn the result of the test. A smear test involves brushing a small sample of cells off the cervix using a spatula. The cells are then studied in a laboratory for evidence of abnormality.
Not only can this process take several weeks but, if a problem is suspected, the woman then has to wait several more weeks to have a colposcopic examination and potential biopsy. Every year, thousands of women who have abnormal smear tests undergo a biopsy, in which a sample of their cervix is removed, only to find they did not have pre-cancerous cells in the first place.
The new screening device, called APX, uses a technology called electrical spectroscopy to monitor the presence of abnormal cells. A probe is placed on the surface of the cervix, and the device generates a mild, painless electric current whilst simultaneously monitoring how the current passes through the cells. Pre-cancerous cells, in the very early stages of malignancy, conduct electricity at a different rate to healthy cells.
The probe is linked to a computer program that can recognise abnormal patterns of electrical flow caused by precancerous cells. Cancerous cells tend to have much lower levels of impedance, which means they conduct more electricity than healthy cervical cells.
The APX system has two applications within the cervical cancer pathway. The APX 100 will be used in secondary care as an adjunct to a colposcopic examination to help clinicians better direct biopsies. This application will be launched in 2011 in the EU. The second application, the APX 200, is currently under development and will be used in primary care at the point of care potentially replacing the smear test.
Within minutes, the APX probe can translate this information into a computerised display that details potential cancerous hot spots. The device has already been tested on more than 500 women within secondary care in four separate trials and a multi-centre European clinical trial is now under way.
Professor Stephen Duffy, Cancer Research UK's screening expert, says: "This technology has shown some interesting results. However, it is still early days. More research is needed to fine-tune the technology, followed by an evaluation to see whether its effectiveness in diagnosing cervical cancer is improved by this fine tuning".
Professor Brian Brown, who developed the device, said: "My primary aim is to see the results of 20 years of research end in a pioneering device that can be adopted into general clinical use. We're very confident of its ability in the colposcopy market and I think it has potential for general screening as well".
For further information, please contact Professor Brian Brown at:
email : B.H.Brown@sheffield.ac.uk