Transvaginal sonography of the endometrium in postmenopausal women

Abstract

Postmenopausal bleeding (PMB)may be a sign of endometrial cancer (EC)but EC canalso be found in postmenopausal women without bleeding.The traditionally acceptedmethod of evaluating the endometrium is dilatation and curettage (D&C)or endometrialbiopsy.Recently non-invasive evaluation of the endometrium by transvaginal sonography(TVS)has been increasingly utilised,sometimes complimented with the use of salineinstillation sonography (SIS).Aims:The aims were:(i)to study the normal variation of endometrial thickness (ET)in arandom sample of postmenopausal women;(ii)to evaluate factors associated with ET anduterine size;(iii)to determine the prevalence of uterine cavity fluid and if the presence offluid is associated with an increased risk of EC;(iv)to assess the possibility of refrainingfrom endometrial biopsy in women with PMB when ET is thin (=4 mm);and (v)toevaluate PMB and ET as predictors of EC in women followed =10 years after a PMB.Material and methods:1000 women aged 45-80 years,randomly chosen from theNational Population Register were invited to answer a questionnaire and undergo agynecological and a TVS examination (Paper I-III).A group of 361 women consecutivelyreferred for investigation of PMB were followed with TVS,a cervical smear and possiblebiopsy for one year (Paper IV).Women (n =394)who presented with PMB during 1987-1990 were followed =10 years after the primary investigation which included TVS (PaperV).Results:A TVS examination was performed in 827 of the 1000 women invited toparticipate and of these 559 were postmenopausal.The majority of the asymptomaticpostmenopausal women had a thin ET (90%)as measured by TVS (Paper I).The onlyfactors associated with ET were use of hormone replacement therapy (HRT)and co-existingfibroids while HRT,fibroids,age,parity,smoking,hypertension and the presence ofdiabetes mellitus were associated with uterine size parameters (Paper II).Uterine cavityfluid was diagnosed in 9%of the asymptomatic women but was not associated with anincreased risk of malignancy when associated with a thin endometrium (Paper III).Theincidence of EC was 0,6%in the 163 women with PMB who had an ET =4 mm at theinitial TVS examination (Paper IV).PMB incurred a 64-fold increase in the risk of EC andno EC was missed when ET was =4 mm even if the women were followed =10 years(Paper V).Conclusions:The study performed in a random sample of the total population did notgive any data to support the use of TVS as a screening method in asymptomatic womenfrom the general population.Neither did the evaluated factors investigated give any supportto screening specific riskgroups.A thin ET (=4 mm)in women with PMB can be safelyfollowed with TVS without endometrial biopsy and uterine cavity fluid does not seem tobe a risk factor for EC in asymptomatic women.A thick endometrium and recurrentbleeding are highly predictive for later development of EC.