Evaluation of Primary Radiation Therapy in Stage I, Group 2, Endometrial Carcinoma

Abstract

TOTAL HYSTERECTOMY preceded by intracavitary radium therapy has been the treatment of choice in clinically operable Stage I carcinoma of the endometrium (3, 9, 11, 12). In about one-third of patients with Stage I tumors, the medical conditions are such as to preclude surgery (6, 7). In this group (Stage I, Group 2: International Classification), radiation has been the primary treatment and it is with this group and its radiotherapy that this study is primarily concerned. The role of external radiation will be discussed, and radium technics will be compared to evaluate the influence of the methods of radiation on the prognosis. In addition, the rate of post-treatment residual and recurrent tumors and the relative morbidity associated with each method will be assessed. Material And Method Between January 1940 and January 1963, 837 primary cases of Stage I endometrial carcinoma were treated at Roswell Park Memorial Institute, Buffalo, N. Y. This series included 285 (268 adenocarcinomas and 17 adenoacanthomas) considered medically inoperable, in which irradiation was the primary treatment. The incidence of this group (34 per cent) agrees with that reported by many institutions which varied from 0.5 to 68 per cent (6). The clinicopathologic features of this material are presented in TABLE 1. The mean age was significantly higher than that in Stage I, Group 1, patients (sixty-one years) treated at our institution. The associated constitutional factors (TABLE I) were frequent and so severe in degree as to make this group a poor surgical risk. The presenting symptoms (TABLE II) were vaginal bleeding, leukorrhea, and pelvic pain. The mean symptom duration was six months. Clinically, the tumor was confined to the corpus which was enlarged in 48 per cent of the patients (uterine canal> 8 em). Fractional curettage revealed the tumors to be adenocarcinoma in 94 per cent of the cases and adenoacanthoma in only 6 per cent. Seventy-eight per cent were graded: of these, 45 per cent were Grade I, 12 per cent were Grade II, and 21 per cent were Grade III. The data on the degree of uterine wall invasion were incomplete, since surgery was not an initial treatment in this series. The statistical analysis in this study was done on a 7040 IBM digital computer, using chisquare, Wilcoxson rank sum and t tests to evaluate the results. Treatment All efforts were made before and during irradiation to improve the medical conditions of the patients and alleviate some or all of the associated constitutional factors. The methods of irradiation were those then current at this institution and are outlined in TABLE III. Intracavitary radium therapy alone or external radiation combined with radium were the methods used. The radium technics were either packing of the corpus by multiple sources or insertion of a radium tandem. In the packing technic, multiple 10-mg radium tubes filled the uterine cavity, and a single 15-mg source was placed in the endocervical canal. This was done in two applications, within a two- to four-week period, each about 3,000 mg hr., to deliver about 6,000 rads at 2-cm depth from the endometrial surface. This technic was used mainly in patients with enlarged uterine cavities (64 per cent). In the tandem technic, a central radium source (1 mg Ra/1 mm active length) was inserted. An applicator with three 15-mg tubes was used in most of the patients with small or normal uterine cavities (73 per cent) to deliver from 5,000to 6,000 rads, 2 em lateral to the tandem. In the combined irradiation methods, external radiation to the whole pelvis was followed by intracavitary radium.