Is liquid-based cytology the way ahead?
Q What are the advantages of so-called 'liquid based cytology' (LBC) technology?
A When using a conventional cytology smear test, no matter how expert the smear-taker is, not all the cells removed from the cervix can be placed on the glass slide and a large proportion will be discarded with the spatula. Studies show this can be as much as 80 per cent of the removed cells, which may include abnormal as well as normal cells.
With LBC systems, however, the sample is collected using a plastic broom that is immediately rinsed into a vial of preservative fluid, thus all the cells removed from the cervix are sent to the laboratory as a cell suspension.
A randomised aliquot of cells containing a true proportional representation of all cells removed from the cervix is placed as a thin layer in a small circle on a glass slide, using an automated processor.
There are fewer unsatisfactory results since the cells are well preserved and clearly visualised, plus any abnormal cells are not hidden in thick areas of the slide even when very few in number or very small in size.
They are quicker and easier for cytology staff to screen, and there are also sufficient cells left in the vial for
repeat or further testing if required.
Despite the obvious advantages of LBC, however, the National Institute for Clinical Excellence, after an extensive review of the technology this year, has decided not to recommend its implementation yet.
It concluded LBC could potentially deliver significant patient benefits, and has instead recommended that pilot projects reassess its effectiveness.
Mr Barry Hill is a chief biomedical scientist at Wigan Royal Infirmary