Omitting Adjuvant Radiotherapy in Endometrial Cancer Increases the Rate of Locoregional Recurrences but Has no Effect on Long-Term Survival The Danish Endometrial Cancer Study

Objectives: In 2 prospective nationwide studies, the Danish Endometrial Cancer Study demonstrated that postoperative radiotherapy (RT) could be omitted in low-and intermediate-risk stage I patients without loss of survival when evaluated after 5 years. In the present study, we evaluated the consequence of this decision on the long-term risk of recurrence and death. Study Design: From 1998 to 1999, 1166 patients newly diagnosed with uterine carcinoma were included. Of these, 586 were low-risk, 231 intermediate-risk, and 78 high-risk stage I. Low-and intermediate-risk patients received standard primary surgery (hysterectomy and bilateral salpingo-oophorectomy), and no postoperative RT was given. Long-term recurrence and survival rates were estimated. Results: After 14 years, 6.3% of low-risk and 22% of intermediate-risk patients had relapsed compared with 32% of high-risk patients. Recurrences were dominated by locoregional relapse in the low and intermediate risk, whereas non-locoregional relapses were prominent in high risk. After locoregional relapse, 1.5% of low and 4.3% of intermediate risk experienced a second relapse dominated by non-locoregional relapses. After curative-intended treatment of vaginal recurrence in the low-and intermediate-risk patients, 100% had complete remission after the first vaginal recurrence, whereas only 74% was cured after the first or the second recurrence. The increased recurrence rate, however, does not seem to affect survival because the survival rate did not change compared to earlier Danish population-based data. Conclusions: We conclude that omitting RT in early stage endometrial cancer increase local recurrences, but without affecting long-term survival.