Placental Leucine Aminopeptidase as a Potential Specific Urine Biomarker for Invasive Ovarian Cancer.

Tetsuya Matsukawa,Kunio Matsumoto,Yukio Kato,Kiyosumi Shibata,Shigehiko Mizutani,Hiroaki Kajiyama,Masato Yoshihara

doi:10.3390/jcm11010222

Abstract

Background: A non-invasive and sensitive biomarker for the detection of ovarian cancer (OvCa) is lacking. We aim to investigate if urinary placental leucine aminopeptidase (P-LAP) can serve as a reliable biomarker for OvCa. Methods: P-LAP activity was measured using a LAP assay kit (Serotech Co., Ltd., Sapporo, Japan) in the urine of 22 patients with benign or borderline malignant ovarian tumors and 18 patients with OvCa. In this assay, L-methionine was added at 20 mM because P-LAP is functional, but other aminopeptidases are inhibited at this dose of L-methionine. Results: The mean urinary P-LAP activity was significantly higher in the OvCa group than in the benign or borderline malignant tumor group. When the cut-off value of P-LAP was determined as 11.00 U/L, its sensitivity and specificity for differentiating invasive cancer were 77.8% and 95.5%, respectively. Conclusion: Although the usefulness of this test should be confirmed in a larger cohort of cases and controls, our study is the first to highlight the importance of urinary P-LAP as a biomarker for OvCa.

Highlights

We report that urine P-LAP activity significantly and sensitively increases in patients with ovarian cancer (OvCa) compared with controls, which nominates urine P-LAP as a sensitive and non-invasive biomarker for detecting OvCa
In patients with benign or borderline malignant tumors, chocolate cysts were observed in 11 patients (50%), and borderline malignant tumors were observed in three patients
In the OvCa group, urinary P-LAP activity was 30.61 ± 29.55 U/L; the value was significantly higher in the latter (p < 0.01; Mann–Whitney U test) (Figure 1)

Summary

Introduction

The identification of novel biomarkers has advanced ovarian cancer (OvCa) research and definitively contributed to the treatment for the disease. Blood biomarkers are widely used for the diagnosis of ovarian cancer; these require an invasive process for sample collection. The discovery of non-invasive and sensitive biomarkers used to detect OvCa is highly desirable. A non-invasive and sensitive biomarker for the detection of ovarian cancer (OvCa) is lacking. P-LAP is functional, but other aminopeptidases are inhibited at this dose of L-methionine. Results: The mean urinary P-LAP activity was significantly higher in the OvCa group than in the benign or borderline malignant tumor group. When the cut-off value of P-LAP was determined as 11.00 U/L, its sensitivity and specificity for differentiating invasive cancer were 77.8% and 95.5%, respectively

Objectives

Methods

Results

Discussion

Conclusion