Long-term survival and prognostic factors in endometrial cancer - a populationbased cohort study

Abstract

Aims: The over-all aims of this thesis were to evaluate the associations between prognostic factors and excess mortality rate, between socioeconomic and immigrant status and incidence rate, in endometrioid (EEC) and non-endometrioid (NEC) endometrial carcinoma. Material and methods: Study I-III were retrospective population-based cohort studies including women resident in a defined geographical area, with endometrial carcinoma. Data on clinicopathological variables were collected from the Western Swedish Healthcare Region Clinical Registry for Endometrial Cancer and the Swedish Quality Registry of Gynecologic Cancer. In study III, data on education and immigrant status were collected from the Swedish Registry of Education and the Statistics Sweden Population Registry. Results: Cohort 2, had a decreased excess mortality rate compared to cohort 1, EMRR 0.62 (95% CI 0.44-0.87) in the NEC group. There was a significant difference in distribution of treatment in cohort 2 (p<0.001), with increased adjuvant chemotherapy in combination with radiotherapy. Excess mortality was not increased with presence of P53 overexpression, EMRR 1.53 (95% CI 0.79-2.97), s-phase fraction >8%, EMRR 1.31 (95% CI 0.68-2.53), and aneuploidy, EMRR 1.79 (95% CI 0.89-3.24). In aneuploidy stage I, grade 2, 5-year relative survival was 0.88 (95% CI 0.78-0.96). Women, aged 50-74-years, with low level of education had higher incidence rate of stage II and III-IV EEC, IRR 1.65 (95% CI 1.13-2.42) and IRR 1.82 (1.33-2.49) compared to high level of education. Conclusions: Clinical protocol used in cohort 2, NEC, was associated with decreased excess mortality. We did not find P53 overexpression, s-phase fraction >8% or aneuploidy associated with increased excess mortality although aneuploidy identified women with impaired survival in stage I grade 2. Lower level of education was associated with increased incidence rates of stage II-IV EEC in 50-74-year-old women.