Comparative study between DNA copy number aberrations determined by quantitative microsatellite analysis and clinical outcome in patients with stomach cancer.
OBJECTIVE
We detected the relative DNA copy numbers (RCNs) at target loci in patients with stomach cancer with quantitative microsatellite analysis. We additionally clarified the relationship between DNA copy number aberrations and the clinical outcome of the patients.


METHODS
Fresh frozen samples were obtained from 30 patients who had undergone surgery for stomach cancer. Seven microsatellite loci in chromosomes 8q, 16q, and 20q and one gene-specific locus (ZNF217) were selected as the target loci. The DNA copy number was obtained relatively to a pooled reference consisting of six microsatellite primer sets selected from the regions where few aberrations have been reported in comparative genomic hybridization analysis. On the basis of the TaqMan PCR system, the internal probes used were carrying donor (6-carboxyfluorescein) and acceptor (6-carboxytetramethylrhodamine) fluorescent molecules complementary to CA repeats in the microsatellite markers and to one gene-specific oligomer in the gene-specific marker.


RESULTS
Chromosome 8q gain, 20q gain, and 16q loss were detected in 18 (60.0%), 8 (26.7%), and 13 (43.3%) cases, respectively. Gains in the RCNs of D8S1801 and D8S1724 were most frequently found (36.7%). There was a significant correlation between the loss of D16S3026 and reduced survival duration (P = 0.0158), and the simultaneous aberrations of D8S1801 gain and D16S3026 loss (double marker positive) was significantly associated with reduced survival duration (P = 0.0008). According to Cox proportional hazards model, the double marker positive was a significant and independent factor indicating an unfavorable prognostic factor (relative risk, 17.176; 95% confidence interval, 2.782-106.026; P = 0.0022).


CONCLUSIONS
RCN aberrations in tumor tissues determined by quantitative microsatellite analysis enable identification of the prognostic factors that correlate with clinical outcome of the patients with stomach cancer.
Suzuki
Seiji
S
Department of Surgery, Tama-Nagayama Hospital, Nippon Medical School, Tama-Shi, Tokyo, Japan. seiji@nms.ac.jp
Egami
Kaku
K
Sasajima
Koji
K
Ghazizadeh
Mohammad
M
Shimizu
Hajime
H
Watanabe
Hidehiro
H
Hasegawa
Hirokazu
H
Iida
Shinya
S
Matsuda
Takeshi
T
Okihama
Yuji
Y
Hosone
Masaru
M
Shimizu
Kazuo
K
Kawanami
Oichi
O
Tajiri
Takashi
T
D000368:Aged; D000369:Aged, 80 and over; D002869:Chromosome Aberrations; D002885:Chromosomes, Human, Pair 16 / Q000235:genetics; D002890:Chromosomes, Human, Pair 20 / Q000235:genetics; D002898:Chromosomes, Human, Pair 8 / Q000235:genetics; D004273:DNA, Neoplasm / Q000235:genetics / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics*; D008875:Middle Aged; D015999:Multivariate Analysis; D016133:Polymerase Chain Reaction; D016016:Proportional Hazards Models; D013274:Stomach Neoplasms / Q000235:genetics / Q000473:pathology*; D016019:Survival Analysis
D004273:DNA, Neoplasm