Sensitive detection of colorectal cancer in peripheral blood by septin 9 DNA methylation assay.
BACKGROUND
Colorectal cancer (CRC) is the second leading cause of cancer deaths despite the fact that detection of this cancer in early stages results in over 90% survival rate. Currently less than 45% of at-risk individuals in the US are screened regularly, exposing a need for better screening tests. We performed two case-control studies to validate a blood-based test that identifies methylated DNA in plasma from all stages of CRC.


RESULTS
Using a PCR assay for analysis of Septin 9 (SEPT9) hypermethylation in DNA extracted from plasma, clinical performance was optimized on 354 samples (252 CRC, 102 controls) and validated in a blinded, independent study of 309 samples (126 CRC, 183 controls). 168 polyps and 411 additional disease controls were also evaluated. Based on the training study SEPT9-based classification detected 120/252 CRCs (48%) and 7/102 controls (7%). In the test study 73/126 CRCs (58%) and 18/183 control samples (10%) were positive for SEPT9 validating the training set results. Inclusion of an additional measurement replicate increased the sensitivity of the assay in the testing set to 72% (90/125 CRCs detected) while maintaining 90% specificity (19/183 for controls). Positive rates for plasmas from the other cancers (11/96) and non-cancerous conditions (41/315) were low. The rate of polyp detection (>1 cm) was approximately 20%.


CONCLUSIONS
Analysis of SEPT9 DNA methylation in plasma represents a straightforward, minimally invasive method to detect all stages of CRC with potential to satisfy unmet needs for increased compliance in the screening population. Further clinical testing is warranted.
Grützmann
Robert
R
Department of Visceral-, Thoracic- and Vascular Surgery, University Hospital Carl Gustav Carus Dresden, Dresden, Germany. Robert.Gruetzmann@uniklinikum-dresden.de
Molnar
Bela
B
Pilarsky
Christian
C
Habermann
Jens K
JK
Schlag
Peter M
PM
Saeger
Hans D
HD
Miehlke
Stephan
S
Stolz
Thomas
T
Model
Fabian
F
Roblick
Uwe J
UJ
Bruch
Hans-Peter
HP
Koch
Rainer
R
Liebenberg
Volker
V
Devos
Theo
T
Song
Xiaoling
X
Day
Robert H
RH
Sledziewski
Andrew Z
AZ
Lofton-Day
Catherine
C
D000328:Adult; D000368:Aged; D000465:Algorithms; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000097:blood* / Q000175:diagnosis* / Q000235:genetics; D019175:DNA Methylation; D005260:Female; D020558:GTP Phosphohydrolases / Q000097:blood / Q000235:genetics*; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D058112:Septins; D016896:Treatment Outcome
D020558:GTP Phosphohydrolases; C474315:SEPTIN9 protein, human; D058112:Septins