Rapid increases in cervical adenocarcinoma incidence have been observed in Western countries in recent decades. Postulated explanations include an increasing specificity of subtype-the capability to diagnose the disease, an inability of cytologic screening to reduce adenocarcinoma, and heterogeneity in cofactors related to persistent human papillomavirus infection. This study examines the possible contribution of these factors in relation with trends observed in Europe. Age-period-cohort models were fitted to cervical adenocarcinoma incidence trends in women ages <75 in 13 European countries. Age-adjusted adenocarcinoma incidence rates increased throughout Europe, the rate of increase ranging from around 0.5% per annum in Denmark, Sweden, and Switzerland to >/=3% in Finland, Slovakia, and Slovenia. The increases first affected generations born in the early 1930s through the mid-1940s, with risk invariably higher in women born in the mid-1960s relative to those born 20 years earlier. The magnitude of this risk ratio varied considerably from around 7 in Slovenia to almost unity in France. Declines in period-specific risk were observed in United Kingdom, Denmark, and Sweden, primarily among women ages >30. Whereas increasing specificity of subtype with time may be responsible for some of the increases in several countries, the changing distribution and prevalence of persistent infection with high-risk human papillomavirus types, alongside an inability to detect cervical adenocarcinoma within screening programs, would accord with the temporal profile observed in Europe. The homogeneity of trends in adenocarcinoma and squamous cell carcinoma in birth cohort is consistent with the notion that they share a similar etiology irrespective of the differential capability of screen detection. Screening may have had at least some impact in reducing cervical adenocarcinoma incidence in several countries during the 1990s.