DNA ploidy status, S-phase fraction, and p53 are not independent prognostic factors for survival in endometrioid endometrial carcinoma FIGO stage I-III.

Affiliation

Department of Obstetrics and Gynecology, Sahlgrenska Academy, Gothenburg University, Gothenburg, Sweden [Email]

Abstract

OBJECTIVE : To assess the effects on relative survival of established and new prognostic factors in stage I-III grade 1-3 endometrioid endometrial carcinoma and in the subgroup of stage I grade 1-2.
METHODS : This was a population-based, retrospective study including all women (n=1113) in the western Swedish healthcare region diagnosed with International Federation of Gynecology and Obstetrics (FIGO) stage I-III grade 1-3 endometrioid endometrial carcinoma in 2006-2011. Histology, grade, stage, and age were prospectively reported to the regional clinical and national cancer registers. DNA ploidy and S-phase fraction were analyzed by flow cytometer. S-phase fraction cut-off was set at ≥8%. Tumor biopsies were classified as diploid if there was one G0/G1 peak or the DNA index was 1.0±0.04. Overexpression of p53 as determined by immunohistochemistry was positive if strong nuclear staining was found in >30% of the neoplastic cells.
RESULTS : Based on univariable statistical analyses we found that 5-year relative survival was significantly associated with S-phase fraction, DNA ploidy, p53, stage, grade, and age. Excess mortality for S-phase fraction ≥8%, aneuploidy, and p53 overexpression was 8, 14, and 8 and times higher, respectively. However, in a multivariable regression model, adjusted for stage, grade, and age, S-phase fraction, DNA ploidy, and p53 were not statistically independent prognostic factors (p=0.413, p=0.107, p=0.208, respectively) for 5-year relative survival in stage I-III grade 1-3 endometrioid endometrial carcinoma. In a subgroup analysis of stage I grade 1-2, aneuploidy identified a subgroup with impaired 5-year relative survival.
CONCLUSIONS : We can conclude that S-phase fraction, DNA ploidy, and p53 overexpression did not improve identification of high-risk patients by stage, grade, and age in stage I-III endometrioid endometrial carcinoma. In stage I, aneuploidy and grade 2 predicted lower relative survival rates than other variables.