The rising frequency of hysterectomy: its effect on uterine cancer rates.

The number of hysterectomies performed in the United States increased approximately 60% between 1965 and 1973, far in excess of population growth. This has altered the population at risk for uterine malignancies, and published incidence rates do not correct for this effect. Using US data, the authors developed correction factors to estimate the actual population at risk, and they applied them to uterine cancer rates. Correction for hysterectomy increased incidence and mortality rates for uterine cancer by 20-45% in any year and changes the time trend by as much as 30% from 1960 to 1973. This effect was greater for endometrial than cervical cancer, and future studies on uterine cancer occurrence should consider prevalence of hysterectomized women in the population.