Impact of hysterectomy on the age-specific incidence of cervical and uterine cancer in Germany and other countries.

BACKGROUND Incidence rates of cervical and uterine cancer are usually determined without elimination of hysterectomized women from the population at risk. The aim of this report is to provide age-specific incidence rates of these cancers uncorrected and corrected for hysterectomized women in Germany and to compare these findings with the international literature. METHODS Most recent incidence estimates of cervical and uterine cancer (11,318 and 26,379 cervical and uterine cancer cases, respectively) of the years 2003-7 in Germany were included. The population at risk was corrected by age-specific prevalence estimates of hysterectomy in Germany. Thereafter, corrected incidence rates were estimated. RESULTS The incidence of cervical and uterine cancer among women aged 65 years or more increased by 67% (cervical cancer from 16.5 to 27.5 and uterine cancer from 79.6 to 133.2 per 100,000 person-years) after correction for hysterectomized women. The distortion of the age pattern of uncorrected incidence rates of cervical cancer for women aged 45-64 years (apparent decline) in Germany virtually disappeared after correction for hysterectomized women. Correction for hysterectomized women resulted in larger relative increases of the cancer rates in the U.S. than European countries. CONCLUSIONS Inclusion of hysterectomized women in the population at risk results in a marked underestimate of the incidences of cervical and uterine cancer among elderly women and potentially biases age-specific incidence patterns and lifetime risk estimates of these cancers. Continuous monitoring of the incidences of cervical cancer corrected for hysterectomized women is needed.