Objectives: We wished to quantify the population-based importance of cervical carcinoma risk factors in Latvia.
Methods: Totally, 223 of 224 eligible cases of incident invasive cervical carcinoma were enrolled during July 1998-February 2001 in Latvia. An age-matched sample of 300 healthy control women was selected from the Latvian population registry and 239 of these women (79%) were enrolled. A demographic and life-style questionnaire was completed, cervical brush samples were analyzed for human papillomavirus (HPV) DNA by PCR and serum samples for HPV antibodies.
Results: Risk factors for cervical cancer in multivariate analysis were HPV type 16 or 18 DNA positivity (OR = 32.4; CI 95% 16.5-63.6) and living in the capital (OR = 2.4; CI 95% 1.2-4.7). Oral contraceptive use was not a risk factor (OR = 0.4; CI 95% 0.2-1.1). A strong protective effect was found for having had more than three Pap smears in the last 5 years (OR = 0.07 CI 95% 0.03-0.19).
Conclusions: Inadequate population coverage of Pap smears, in spite of excessive smear usage, caused 28.4% of cervical cancers in age groups eligible for screening. HPV type 16 infection was the most important risk factor for cervical cancer in Latvia, with a population-attributable risk percent for all ages of 58.5%.