Intensified screening among high risk women within the organised screening programme for cervical cancer in Finland

Based on a five-year follow-up of 130 692 women who participated in the five-yearly organised screening in Finland in 1995, we estimated the risk for incident invasive cervical cancer and severe precancerous lesion for groups of women with different combinations of high-risk determinants at baseline.

Compared to women with normal cytology and no symptoms at the index screen, the risk of developing invasive cervical cancer during the next screening interval was significantly elevated in women with abnormal cytology at baseline screen (RR 5.8, 95% CI 2.6-13.1); additionally, the risk of cervical intraepithelial neoplasia grade 3 (CIN3) lesions was even higher (RR 9.4, 95% CI 6.9-12.5), both results after removing respective screen detected cases at index screen. Among women with symptoms of vaginal bleeding or abnormal vaginal discharge but normal cytology the risk of invasive cervical cancer was increased but not significantly (RR 2.4, 95% CI 0.9-6.3) and the risk of CIN3 lesions was only slightly elevated (RR 1.5, 95% CI 0.95-2.4). In women less than 40 years of age, the risk of cervical cancer was 50% higher than in women 40 years or more in those with normal cytology and no symptoms, however not significantly. Symptoms indicated a similarly elevated risk for cancer in both age groups. After abnormal cytology there was a nine-fold risk for cancer in young women (under 40 years) and a six-fold risk in old women (40 years or more) when compared to women aged 40 or more with no symptoms and normal cytology. In young women CIN3 lesions were found in great excess, three times more often, compared to those aged 40 and over.

In all, selective intensified screening for cervical cancer complementing the five-yearly unselective programme is feasible for women with abnormal cytological findings at an acceptable level of incremental cost.