A role for adjuvant radiation in clinically early carcinoma of the endometrium?

Whereas radiation is recognized as a highly effective treatment modality in endometrial cancer, its role as adjuvant treatment after surgery in clinically early disease is declining. Randomized trials of both pelvic external beam radiation and vaginal vault brachytherapy have been conducted to evaluate their respective contribution. These trials have demonstrated that external beam radiation may decrease pelvic relapse rates compared with observation alone in high intermediate-risk groups, but this does not improve survival. Post Operative Radiation Therapy in Endometrial Carcinoma (PORTEC) Study 2 confirmed that vaginal vault brachytherapy was equivalent to external beam radiation in preventing vaginal relapse. However, given the high rate of salvage of patients who develop vaginal recurrence and the significant risk of death from comorbidities, questions arise as to the relative merit of administering adjuvant radiation for all compared with a strategy of observation after surgery with treatment only for the 10% who have a relapse.The contribution of adjuvant radiation for high-risk disease, including those with grade III tumors with deep myometrial penetration, however, remains to be determined in ongoing trials.