[The value of postoperative irradiation in endometrial cancer of pathohistologic stage I]

In a prospective therapeutic study, 571 cases of endometrial cancer in pathological stage I were treated initially with total hysterectomy and received 6 weeks after surgery double high-dose-rate iridium 192 irradiation of the vagina (afterloading technique). The single dose was 700 cGY (at 2 cm distance from the applicator axis). Postoperative treatment planning was based on the prognosticators of depth of myometrial invasion and tumor grading with subtypes. External irradiation was prescribed only for patients with poor prognostic factors (Cobalt-60,5600 cGY on the pelvis wall, 30 fractions). At the time of this report, the patients had been followed up for 6 to 96 months after their original therapy. Survival was calculated by the life table method. 327 cases with slight tumor infiltration, independent of the tumor morphology, received postoperative vaginal irradiation only. Survival rate was 90.6%. 27 cases with tumor infiltration of the middle third of the myometrium and grade 1 tumors, received also only vaginal irradiation. Survival rate was 100%. 101 cases with tumor infiltration of the middle third of the myometrium and grade 2 and 3 tumors, received vaginal irradiation plus external irradiation. Survival rate was 89.9%. 116 cases with tumor infiltration of the external third of the mymetrium and any tumor grade, received vaginal irradiation plus also external irradiation. In these patients with poor prognosis, the survival rate was 85%. Differences between groups are not significant. Considering the treatment group with good prognosis and the group with poorer prognosis and the additional external irradiation, the survival figures were quite similar (90.6% and 87.9% respectively). In spite of the unfavorable situation of patients with poor prognosticators, treatment results after the additional external irradiation were rather similar to those cases with good prognosticators and without external irradiation. The value of external irradiation in cases of endometrial cancer in stage I with unfavorable prognosticators seems to be quite clear. This therapy improvement was all the better, because side effects of external irradiation were low (0.2% rectovaginal fistulas) and in case of irradiation of the vagina only, no severe side effects occurred. Relapse rate for the treatment group with good prognosis and vaginal irradiation only was 0.6% (2 from 354) and for the group with poor prognosis and additional external irradiation 2.8% (6 from 217) respectively.