Adenocarcinoma of the endometrium: Analysis of 256 cases with carcinoma limited to the uterine corpus: Pathology review and analysis of prognostic variables

Abstract

Histologic specimens of all patients undergoing hysterectomy for clinical Stage I adenocarcinoma of the endometrium at Stanford University Hospital between 1959 and 1975 were reexamined. From this group 256 acceptable cases of adenocarcinoma confined to the uterine corpus (Pathologic Stage I) were identified. In patients treated with initial surgery, relapse rate was highly correlated with depth of myometrial invasion ( P = 0.0001) and also with the histologic grade of the uterine adenocarcinoma ( P = 0.008). Twenty-six patients (10%) had lesions with papillary architecture and anaplastic cytology similar to papillary serous carcinoma of the ovary. These women with uterine papillary serous carcinoma (UPSC) had a 50% relapse rate and accounted for one-half the treatment failures ( 13 26 ) in the entire study group. Six of the seven upper abdominal relapses in this study were in patients with UPSC, suggesting that this histologic variant may behave more like ovarian serous carcinoma than the usual endometrial adenocarcinoma. Twenty-one patients (9%) had endometrial carcinomas with extensive mucinous differentiation (mucinous carcinoma), while 38% of all the cases of endometrial carcinoma showed at least some focal mucin production. Twenty percent showed focal squamous differentiation. Neither mucinous nor squamous differentiation, as we have applied these designations, were significantly correlated with relapse rate. Among the patients undergoing hysterectomy for clinical Stage I adenocarcinoma, 99 patients were found on review to have lesions which fell short of our current criteria for diagnosis of carcinoma in the uterine corpus and were reinterpreted as metaplasia and/or hyperplasia. None of these patients subsequently developed clinical relapse. The results of this study suggest a need for modification in the FIGO grading system for endometrial cancer and also support a definition of well-differentiated endometrial carcinoma more restrictive than that commonly employed.