Endometrial carcinoma: results of primary surgery on FIGO stages Ia-Ic and predictive value of histopathological parameters.

The aim of the present investigation was to see if alternative histopathological parameters could identify a smaller high risk group than commonly seen using routine histopathological parameters. The material consisted of 150 primary resected patients of FIGO Ia-Ic diagnosed as endometrial carcinoma and 12 cases of atypical hyperplasias which were suspected to contain small areas of carcinoma. The patients were treated from December 1979 to April 1993 at the Department of Obstetrics and Gynecology, University Hospital, Lund, Sweden. Those with deep myometrial invasion (> 50%) were given external radiotherapy (20-30 Gy) postoperatively. The follow-up period ranged from 2.5 to 5 years with 116 patients followed-up for more than 5 years. As no therapy was given before surgery we could investigate histopathologic variables such as degree of differentiation and cytology, number of mitoses per high power field (x 40), nuclear polymorphism, mode of invasion, the extension of myometrial invasion, vessel invasion as well as grade of lymphocyte reaction around the tumour cells. We found the degree of differentiation, vessel invasion, number of mitoses, mode of invasion and cytologic abberation to be significant prognostic parameters. The frequency of deep myometrial invasion (> 50%) was extremly high (51/150 = 33%). However, this usually strong parameter was only significant when comparing stage Ia with Ic. Thus the prognostic capacity of myometrial invasion is diminished in primary hysterectomized patients. In the regression analyses only vascular invasion remained significant. By combining vascular invasion with the degree of differentiation we diminished the high-risk group consisting of candidates for further investigation and treatment. Thus a high risk group consisting of poorly differentiated carcinomas with vascular invasion was constructed comprising 24 of 139 patients with a mortality rate of 60%.