Incidence of ovarian cancer after hysterectomy: a nationwide controlled follow up.
OBJECTIVE
To estimate the risk of developing ovarian cancer after abdominal (total or subtotal) hysterectomy on benign indication.


METHODS
Prospective historical cohort study with 12.5 years of follow up.


METHODS
Denmark, nationwide.


METHODS
All Danish women (aged 0 to 99 years) having undergone hysterectomy with conservation of at least one ovary for a benign indication from 1977 to 1981 (n = 22,135). Follow up was conducted from 1977 to 1991. The reference group included all Danish women who had not undergone hysterectomy, age-standardised according to the hysterectomy group (n = 2,554,872).


METHODS
Registry data derived from the Danish National Register of Patients (diagnoses and operation codes) and the Civil Registration System (information about general population, including time of death).


METHODS
Incidence rate of ovarian cancer, lifetime risk of ovarian cancer, relative risk of ovarian cancer.


RESULTS
Seventy-one women developed ovarian cancer on average 7.0 years after hysterectomy and 10,659 women in the reference group had ovarian cancer diagnosed after on average 6.4 years. The incidence rate of ovarian cancer was 0.27 per 1000 person-years in the group that had undergone hysterectomy and 0.34 per 1000 person-years in the general population (age-standardised). The extrapolated lifetime risk of developing ovarian cancer was 2.1% after hysterectomy and 2.7% in the general population (RR 0.78; 95% CI 0.60-0.96).


CONCLUSIONS
The risk of ovarian cancer is lower among women who have undergone hysterectomy compared with those who have not. The protection seems to decrease with time.
Loft
A
A
Department of Obstetrics and Gynaecology at Rigshospitalet, University of Copenhagen, Denmark.
Lidegaard
O
O
Tabor
A
A
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003718:Denmark / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007044:Hysterectomy / Q000009:adverse effects / Q000706:statistics & numerical data*; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000453:epidemiology*; D010052:Ovariectomy / Q000706:statistics & numerical data; D011446:Prospective Studies; D012307:Risk Factors; D013997:Time Factors