Pro-Gastrin Releasing Peptide: A New Serum Marker for Endometrioid Adenocarcinoma

Gastrin-releasing peptide (GRP) is thought to play a role in the metastatic process of various malignancies. The more stable precursor of GRP, pro-GRP (ProGRP), has been shown to be secreted by neuroendocrine tumors. This study was designed to assess the validity of ProGRP as a diagnostic marker in endometrioid adenocarcinomas (EAs) of the endometrium.

Thirty-seven patients with a diagnosis of EA, 23 patients with endometrial hyperplasia, and 32 age-matched controls with normal endometrial histology were recruited for this study. Serum ProGRP and cancer antigen 125 (CA125) values were compared between groups.

Median serum ProGRP levels were significantly higher in the cancer group compared to corresponding levels in both the hyperplasia and control groups (p = 0.008 and p < 0.001 respectively; endometrial cancer: 27.5 pg/mL; hyperplasia: 16.1 pg/mL; controls: 12.9 pg/mL). Age and endometrial thickness were positively correlated with ProGRP levels (r = 0.322, p = 0.006 and r = 0.269, p = 0.023, respectively). Receiver Operating Characteristic curve analyses for EA revealed a threshold of 20.81 pg/mL, with a sensitivity of 60.7% and specificity of 81.4%, positive predictive value of 68% and negative predictive value of 76.1%.

Significantly higher ProGRP levels were observed in patients with EA than in controls. Serum ProGRP has good diagnostic sensitivity and specificity for EA.