Increased plasma DNA integrity in cancer patients.
Tumor-released DNA in blood represents a promising biomarker for cancer detection. It has been postulated that tumor necrosis causes release of DNA of varying sizes, which contrasts apoptosis in normal tissue that releases smaller and more uniform DNA fragments. To test the hypothesis that increased DNA integrity, i.e., a longer DNA strand, is a tumor-associated marker in plasma, we determined the genomic DNA integrity index in plasma DNA using real-time PCR assays. A DNA integrity index and DNA concentration in plasma were determined in 61 patients with gynecological and breast cancers and 65 female patients without neoplastic diseases. We found that the area under the receiver-operating characteristic curve for DNA integrity index was 0.911 for cancer versus nonneoplastic patients. Given 100% specificity, the highest sensitivity achieved in detecting the cancer group was 62% (95% confidence interval = 0.50-0.74) at the index cutoff of 0.59. Fifty percent of stage I cancers had a DNA integrity index above this cutoff. All 11 patients with benign adnexal masses that clinically can be confused with malignant gynecological neoplasms demonstrated DNA integrity index < 0.59. Our findings suggest that increased DNA integrity in plasma DNA is associated with cancer, and measurement of DNA integrity may provide a simple and inexpensive measure for cancer detection.
Wang
Brant G
BG
Department of Pathology, The Johns Hopkins Medical Institutions, Baltimore, Maryland 21231, USA.
Huang
Han-Yao
HY
Chen
Yu-Chi
YC
Bristow
Robert E
RE
Kassauei
Keyanunoosh
K
Cheng
Chih-Chien
CC
Roden
Richard
R
Sokoll
Lori J
LJ
Chan
Daniel W
DW
Shih
Ie-Ming
IeM
D016022:Case-Control Studies; D004273:DNA, Neoplasm / Q000097:blood* / Q000235:genetics; D005260:Female; D005833:Genital Neoplasms, Female / Q000235:genetics*; D006801:Humans; D012372:ROC Curve; D020133:Reverse Transcriptase Polymerase Chain Reaction
D004273:DNA, Neoplasm