INCIDENCE OF CANCER OF THE CORPUS UTERI IN THE ELDERLY IN CANADA, AFTER ADJUSTMENT FOR PREVIOUS HYSTERECTOMY

The objectives of this study were first, to describe the trends in rat es of cancer of the corpus uteri in Canada between 1969 and 1990 after adjustment for previous hysterectomy and second, to assess the role o f improved diagnosis in recent periods. Cases were defined as women of ages 65 years and older with a diagnosis of cancer of the corpus uter i. Rates were calculated using national data and adjusted to reflect p revious hysterectomy. A chart review was performed at a regional cance r centre to obtain information on stage of the disease, duration of th e symptoms and initial method of diagnosis. Age-specific rates, adjust ed for previous hysterectomy, showed increases in women aged 70-74, 75 -79 and 80-84 years. The cohort analysis revealed that the 1915-19 bir th cohort experienced a high incidence of cancer of the corpus uteri i n women aged 55-69 years at diagnosis. Stage I disease was more common in recent periods at the regional centre (71.1%, 74.1% and 92.3% for 1969-72, 1980-81 and 1990-91; chi(2) for linear trend 10.676, P = 0.00 1). In 1990-91, 6.7% of cases were identified by endometrial biopsy. I n conclusion, incidence adjusted for hysterectomy prevalence is increa sing in women aged 65-84 years in Canada. There is increased risk for women 55-69 years of age born in 1915-19 cohort. There is weak evidenc e of improved diagnosis in elderly women in recent periods.