By Joanne Ellul
Researchers from Queen Mary University, London, studied 4,012 women aged 20-69 and found no evidence that screening women aged 22-24 reduced the incidence of cervical cancer.
However, the study found that screening women between the ages of 30 and 37 was associated with a reduction in cancer risk of 43-60 per cent over the next five years.
Separate research from the University of Ottawa found that while cervical examination by colposcopy detected highly abnormal tissue, it could lead to overtreatment, because this tissue sometimes returned to normal without intervention.
Researchers studied 4,400 women aged 20-59 with borderline or low-grade abnormal smears. They concluded that colposcopy causes more side effects and later pregnancy complications than surveillance.
What do the researchers say?
The Queen Mary University researchers found that few, if any, of the cancers occurred through a lack of screening.
Professor Peter Sasieni, who led the study, said that treatment might be associated with premature delivery during subsequent pregnancies.
'There is no doubt the risk of cancer in women aged under 25 who are vaccinated before exposure to HPV will be low enough to make screening at such an age unjustifiable,' he said.
The University of Ottawa researchers said the side-effects reported for the colposcopy were of longer duration and of greater severity than those reported for surveillance.
There was also no clear psychological benefit of this type of screening, they said.
What do other researchers say?
William Soutter, a consultant gynaecologist at Hammersmith Hospital, London, in response to the study led by Professor Sasieni, said: 'It is well recognised that cervical cytology testing is not perfect. Estimates of its accuracy suggest that it fails to detect 25-50 per cent of cases of high grade pre-invasive disease.'
He added that those who have had more smears will have greater protection. 'This explains why screening is more effective in preventing cancer in the older women.'