Poor quality cervical smears could play a role in missed diagnosis of cervical cancer, according to an analysis.

The cervical smear screening program has led to a seven per cent annual fall in deaths from cervical cancer in the UK. But there are potential problems arising from the relatively high number of smears taken that are inadequate in some way.

Researchers reviewed the quality of over 25,000 smears tests done in one hospital between April 1995 and March 1996. Just under 2,000 women had a smear deemed poor quality - either because there were too few cells, or the tissue was obscured by blood, inflammation or bacteria. In some cases the cells were spread too thickly or the amount of fixing solution was insufficient.

The majority of the women having a poor quality smear were followed up to see what consequences there were for their health. Of this group, 13 per cent developed abnormalities. In some cases these had cleared up on re-testing, but 3.6 per cent - 71 women - had cellular abnormalities that persisted. Of these, 32 had minor changes, and the rest had serious changes. In all, women with poor quality smears were twice as likely as those with good quality smears to go on to develop cancerous changes. The increased risk is not, in fact, statistically significant but the researchers say that larger studies should now be done.

Source

Journal of Clinical Pathology August 2003