The Continuing Increase in Adenocarcinoma of the Uterine Cervix: A Birth Cohort Phenomenon

BACKGROUND: Adenocarcinoma of the uterine cervix has been reported to be increasing among young white women and earlier studies suggest a birth cohort pattern for the observed increase. No study, however, has examined the time trends of adenocarcinoma of the cervix by birth cohort. METHODS: Using Surveillance, Epidemiology, and End Results (SEER) data through 1990, the current study is designed to examine the time trends of invasive adenocarcinoma by birth cohort. An age-period-cohort model was fitted to the annual-age-specific rates to identify the components of birth cohort and time period as determinants of the observed time trends. RESULTS: The results from this study clearly show that invasive adenocarcinoma of the uterine cervix has been increasing in both whites and blacks, but the increase is statistically significant only among whites, reaching 4.2 percent per year for those born since 1935. The results also show that the recent increase in invasive adenocarcinoma started among those born around the mid 1920s, and a strong birth cohort effect is largely responsible for the observed increase. CONCLUSION: Invasive adenocarcinoma of the uterine cervix is increasing among recent birth cohorts. Analytical epidemiological studies are urgently needed to explore the risk factors responsible for the increase. The time trends for adenocarcinoma of the cervix should also be carefully monitored in the coming years.