M2-PK as a novel marker in ovarian cancer. A prospective cohort study.
BACKGROUND
Pyruvate kinase isoenzyme M2-PK is instrumental to tumour metabolism and hence over-expressed in tumour cells leading to detectable plasma concentrations.


OBJECTIVE
To assess the degree of association between M2-PK plasma concentrations and ovarian cancer and to determine the cut-off values for its sensitivity and specificity for differentiating between benign and malignant ovarian disease.


METHODS
The Gynaecological Cancer Centre at both King's College and St. Thomas' Hospitals, London, UK.


METHODS
Patients with suspected ovarian cancer referred to the above centre were recruited prospectively during the years 2004-2005. Blood samples were collected before surgery for plasma M2-PK assays. Results were assessed with respect to cancer diagnosis, patient and tumour characteristics. Statistical analysis including the receiver operator characteristic (ROC) curve was performed using Analyse-It and SPSS V 13.


RESULTS
100 patients with age range 14-88 years and a median of 57 years were recruited in the study. Of whom 52 were diagnosed with invasive ovarian cancer. Of these 35 (67%) were Stage III and above with two secondary tumours. M2-PK was not related to patient age (p = 0.43). There was a significant correlation between CA125 and M2-PK (p < 0.001). The mean M2-PK concentration in cancer patients was 52 U/ml versus 27 U/ml in patients with benign conditions (p < 0.001). At a cut-off value of 22 U/ml the sensitivity of M2-PK for detecting cancer was 70% with a specificity of 65%.


CONCLUSIONS
M2-PK was significantly raised in ovarian cancer patients, however its role in clinical practice needs further evaluation.
Ahmed
A S
AS
South East London Cancer Network, Gynae-Oncology Department, Guy's and St Thomas', and King's College Hospitals, London.
Dew
T
T
Lawton
F G
FG
Papadopoulos
A J
AJ
Devaja
O
O
Raju
K S
KS
Sherwood
R A
RA
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008131:London; D008875:Middle Aged; D009367:Neoplasm Staging; D010051:Ovarian Neoplasms / Q000175:diagnosis* / Q000201:enzymology*; D011446:Prospective Studies; D011770:Pyruvate Kinase / Q000097:blood*; D015203:Reproducibility of Results
D014408:Biomarkers, Tumor; D011770:Pyruvate Kinase