Bladder cancer diagnosis and identification of clinically significant disease by combined urinary detection of Mcm5 and nuclear matrix protein 22.
BACKGROUND
Urinary biomarkers for bladder cancer detection are constrained by inadequate sensitivity or specificity. Here we evaluate the diagnostic accuracy of Mcm5, a novel cell cycle biomarker of aberrant growth, alone and in combination with NMP22.


METHODS
1677 consecutive patients under investigation for urinary tract malignancy were recruited to a prospective blinded observational study. All patients underwent ultrasound, intravenous urography, cystoscopy, urine culture and cytologic analysis. An immunofluorometric assay was used to measure Mcm5 levels in urine cell sediments. NMP22 urinary levels were determined with the FDA-approved NMP22® Test Kit.


RESULTS
Genito-urinary tract cancers were identified in 210/1564 (13%) patients with an Mcm5 result and in 195/1396 (14%) patients with an NMP22 result. At the assay cut-point where sensitivity and specificity were equal, the Mcm5 test detected primary and recurrent bladder cancers with 69% sensitivity (95% confidence interval = 62-75%) and 93% negative predictive value (95% CI = 92-95%). The area under the receiver operating characteristic curve for Mcm5 was 0.75 (95% CI = 0.71-0.79) and 0.72 (95% CI = 0.67-0.77) for NMP22. Importantly, Mcm5 combined with NMP22 identified 95% (79/83; 95% CI = 88-99%) of potentially life threatening diagnoses (i.e. grade 3 or carcinoma in situ or stage ≥pT1) with high specificity (72%, 95% CI = 69-74%).


CONCLUSIONS
The Mcm5 immunoassay is a non-invasive test for identifying patients with urothelial cancers with similar accuracy to the FDA-approved NMP22 ELISA Test Kit. The combination of Mcm5 plus NMP22 improves the detection of UCC and identifies 95% of clinically significant disease. Trials of a commercially developed Mcm5 assay suitable for an end-user laboratory alongside NMP22 are required to assess their potential clinical utility in improving diagnostic and surveillance care pathways.
Department of Pathology and Cancer Institute, University College London, London, United Kingdom.
John D
JD
Kelly
Tim J
TJ
Dudderidge
Alex
A
Wollenschlaeger
Odu
O
Okoturo
Keith
K
Burling
Fiona
F
Tulloch
Ian
I
Halsall
Teresa
T
Prevost
Andrew Toby
AT
Prevost
Joana C
JC
Vasconcelos
Wendy
W
Robson
Hing Y
HY
Leung
Nikhil
N
Vasdev
Robert S
RS
Pickard
Gareth H
GH
Williams
Kai
K
Stoeber
D000368:Aged; D019540:Area Under Curve; D014408:Biomarkers, Tumor / Q000652:urine*; D002277:Carcinoma; D002295:Carcinoma, Transitional Cell / Q000175:diagnosis* / Q000652:urine; D018797:Cell Cycle Proteins / Q000652:urine*; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D057230:Limit of Detection; D008297:Male; D008875:Middle Aged; D009687:Nuclear Proteins / Q000652:urine*; D012372:ROC Curve; D018709:Statistics, Nonparametric; D001749:Urinary Bladder Neoplasms / Q000175:diagnosis* / Q000652:urine
D014408:Biomarkers, Tumor; D018797:Cell Cycle Proteins; C489423:MCM5 protein, human; D009687:Nuclear Proteins; C100379:nuclear matrix protein 22