Intraoperative evaluation of prognostic factors in stage I endometrial cancer by frozen section: how reliable?

The incidence of pelvic/paraaortic lymph node metastases is related to the grade of the tumor, the depth of myometrial invasion and the cervical involvement. These prognostic factors determine the initial surgery. Intraoperative evaluation and frozen section (FS) have been used for this purpose in order to identify patients requiring pelvic/paraaortic lymphadenectomy and adjuvant therapy, thereby eliminating routine lymphadenectomy with its complications. We used frozen section for this purpose and identified accurately 90% of patients requiring pelvic/paraaortic lymphadenectomy. The depth of myometrial invasion was accurately predicted in 90.6% and histologic grade in 91.9% of the patients; however, 60% of patients with cervical involvement were identified by FS. We recommend the use of frozen section as an inexpensive, simple and accurate way of estimating the poor prognostic factors.