- Patients must have histologically-confirmed type I primary endometrial carcinoma (EC). Diagnosis biopsy must contain 3-12 mg of tumour cellularity/stroma (Tumour: 5-20 mm) and this will be checked in the central laboratory for this trial. If tumour cellularity/stroma is inadequate, one re-biopsy with adequate tumour cellularity/stroma will be mandatory before study entry.