PORTEC-2

PORTEC-1 had shown that external beam radiotherapy reduces locoregional recurrence without improving survival in stage I endometrial cancer, and that most recurrences were in the vagina. PORTEC-2 randomised 427 women with high-intermediate-risk stage I disease (defined by age, grade and depth of invasion) to vaginal brachytherapy or external beam pelvic radiotherapy. The primary endpoint was vaginal recurrence.

Vaginal recurrence rates were low and similar in both arms, with no difference in overall survival, and vaginal brachytherapy caused far less gastrointestinal toxicity and better quality of life. It became the standard adjuvant treatment for this risk group worldwide. The later molecular analysis of the PORTEC trials showed that POLE-mutated tumours almost never recur whatever the treatment, and that p53-abnormal tumours do poorly, the basis of the molecular classification now used to tailor adjuvant therapy.