Cervical screening intervals should vary for different age groups

A study reported in the July issue of the British Journal of Cancer “calls into question the policy of having a uniform screening interval” for cervical cancer among women aged 20 to 64.

Screening intervals vary greatly from country to country, report Dr. Peter Sasieni of Cancer Research UK in London and colleagues. Many women in Europe, for example, are offered screening only every five years, whereas annual screening is common in North America –a practice the authors consider “overkill”. They also question the value of cervical screening in women under age 25.To determine appropriate screening intervals, the researchers conducted a case-control study comparing the screening histories of 1305 women ages 20 to 69 who had been diagnosed with invasive cervical cancer with those of 2532 age-matched controls.The data were analysed in terms of time since last negative, and time since last screening smear.Three-yearly screening offered 84% protection against cervical cancer at ages 40 to 54 compared with 73% with five-yearly screening, and was almost as good as the 88% protection offered by annual screening.But for women aged 55 to 69, the researchers found little difference between screening every five years (83%), every three years (87%), and annual screening (87%).In women aged 20 to 39, even annual screening was not as effective (76%) as three-yearly screening in older women, although it was more effective than three-yearly screening (61%) and five-yearly screening (30%).The results suggest that the present policy of a uniform screening interval for all women aged 20 to 64 should be abandoned in favour of an interval that changes with the woman’s age, the authors conclude. They suggest the following for the UK: under age 25, do not screen; 25-49, three-yearly screening; 50-64, 5-yearly screening; 65 and older, only screen those who have not been screened since age 50.(Source: Br J Cancer 2003;88: Reuters Health: July 1, 2003: Oncolink)