A discordant histological risk classification in preoperative and operative biopsy in endometrial cancer is reflected in metastatic risk and prognosis

Abstract

Introduction: In endometrial cancer, tissue for histological evaluation is obtained preoperatively (endometrial biopsy) and operatively (hysterectomy specimen). We investigated if a discordant risk classification based on preoperative and operative biopsy is reflected in metastatic risk and prognosis.

Patients and methods: One thousand three hundred and seventy-four patients were prospectively included in a multicentre setting (Molecular Markers for Treatment of Endometrial Cancer (MoMaTEC) study). Preoperative and operative specimens were classified as high risk if non-endometrioid histology or endometrioid grade 3; otherwise low risk. Disease specific survival differences were calculated by means of Kaplan-Meier and Cox proportional hazard models.

Results: Discordant risk was found in 207 (16%) cases. Lymph node metastases were detected in 7% and 23% of patients with concordant low and high risk respectively versus 14% and 20% in the discordant groups (p<0.001). Five-year disease specific survival in the discordant groups proved intermediate (75-80%) to concordant low (94%) or high (58%) risk. Both operative and preoperative biopsy high-risk results have independent prognostic impact on disease specific survival with adjusted hazard ratios of 2.4 (95% confidence interval (95% CI) 1.5-3.9) and 2.1 (95% CI 1.3-3.2) respectively by Cox analysis.

Conclusions: Discordant risk in preoperative biopsy and hysterectomy identifies an intermediate group with respect to disease spread and prognosis. Preoperative biopsy results remain important also with the hysterectomy histology available.