The clinical significance of malignant peritoneal cytology in stage I endometrial carcinoma

The prevalence of malignant peritoneal cytology in patients with International Federation of Obstetrics and Gynecology (1971) stage I endometrial carcinoma and its predictive value for recurrence of disease following hysterectomy were analyzed by numerically pooling the crude results of independent studies. Malignant cytology occurred in 8.3, 12.1 and 15.9% of patients with grade 1, 2 and 3 histology, respectively, and in 7.6% and 17.2% of patients with superficial and deep myometrial invasion, respectively. Prevalence was heterogeneous in the groups with grade 1 histology, grade 2 histology and superficial invasion, and homogeneous in the groups with grade 3 histology and deep invasion. This, together with a technical false positive rate of approximately 5% in the diagnosis of malignant cytology, suggests that the pooled values of prevalence for the low grade and superficially invasive groups may be overestimated. Malignant cytology was strongly associated with disease recurrence (pooled odds ratio of 4.7 with a 95% confidence interval of 3.5–6.3). Qualitative review of the literature suggests that this is largely due to the association of malignant cytology with other adverse prognostic factors which dominate the clinical course of the disease. In the absence of other adverse prognostic factors, the true prevalence of malignant cytology is low. This limits the clinical utility of cytology as an independent predictor of either overall recurrence or site of recurrence. Routine adjuvant treatment of patients with malignant cytology is therefore not justified.