CERVICAL CANCER/SCREENING

Cervical cancer affects around 2,800 women each year in the UK. Second most common cancer in women under 35. Virtually all cancers of the cervix are caused by persistent infection with human papillomavirus (HPV), a virus transmitted by skin-to-skin contact in the genital area. Infection is common but for most women does not result in cervical cancer. Cervical cancer is detectable at an early stage by cervical screening, which saves thousands of lives each year. Girls in England aged 12-13 years are offered vaccination against the two most common types of high-risk HPV (HR-HPV 16 and 18).

Cervical screening

To detect and prevent cervical cancer, cervical cytology (sampling of cells from the cervix) screening is offered to women in the UK as follows:

• England: women aged 29-49 years every 3 years; women aged 50-64 years, every 5 years

• Northern Ireland: women aged 20-64 years, every 3-5 years

• Scotland: women aged 20-60 years, every 3 years

• Wales: women aged 20-64 years, every 3 years

Knowledge of the link between HR-HPV and cervical cancer has transformed cervical screening, which is now based on HPV triage. If HR-HPV is not present (even in cells which show low grade changes) the woman can be returned to routine screening with no higher risk of developing cervical cancer. Where HR-HPV is detected, women are referred rapidly for further investigation (colposcopy). 

It is important to encourage women to attend for screening when invited, but in recent years uptake has been falling. There is evidence that the HPV vaccination programme has reduced cervical disease both in vaccinated and unvaccinated women in later life but around 2,600 women are diagnosed with cervical cancer in England, and around 690 deaths, every year. 

Cervical cytology

The traditional cervical screening technique of smearing cervical cell samples on a glass slide before fixing for microscopic examination (the cervical smear) has been replaced by liquid-based cytology. The new technique allows the sampled cells to be dispersed directly in preservative fluid; the sample can then be spun and treated to remove obscuring materials (blood, pus, mucus). This reduces the risk of an inadequate sample and hence the number of repeat screenings, and laboratories can return results more quickly.

Training

Nurses and doctors who carry out cervical screening must be adequately trained, and update of skills every 3 years is mandatory. Cytology training is a fundamental part of the NHS cervical screening programme

Referral

If there are clinical features suggestive of cervical cancer, a smear is not required before referral. A previous normal smear should not delay referral if indicated.

Colposcopy Examination of the cervix at up to 10x magnification, with a binocular microscope. Women are referred for colposcopy following an abnormal cervical cytology result.