[Influence of neoadjuvant chemotherapy on microsatellite instability in gastric carcinoma].
OBJECTIVE
Most results from clinical trials of neoadjuvant chemotherapy for gastric carcinoma are certain. Meanwhile, microsatellite instability (MSI) is thought to be a new mechanism of cell canceration. This study was to investigate the influence of neoadjuvant chemotherapy on MSI in gastric carcinoma.


METHODS
Two microsatellite loci D2S123 and D3S1298 in tumor samples from 48 patients with gastric carcinoma, received preoperative chemotherapy of 5-fluorouracil (5-FU) and leucovorin (CF), were analyzed by polymerase chain reaction (PCR), electrophoresis on 8% denatured polyacrylamide gel, and silver staining. The microsatellite statuses of preoperative and postoperative specimens were compared. Chi-square test was used to analyze the influence of neoadjuvant chemotherapy on MSI in gastric carcinoma.


RESULTS
The detection rate of MSI was significantly higher in preoperative samples than in postoperative samples (31.3% vs. 12.5%, P=0.026). After neoadjuvant chemotherapy, 9 cases changed from MSI-positive to MSI-negative, while no MSI-negative cases became MSI-positive.


CONCLUSIONS
The neoadjuvant chemotherapy regimen of 5-FU/CF can induce some MSI-positive gastric carcinoma change to MSI-negative, but has no effect on MSI-negative cases.
Sun
Xiao-Wei
XW
State Key Laboratory of Oncology in South China, Guangzhou, Guangdong, 510060, P. R. China. d2s123@163.com
Zhan
You-Qing
YQ
Li
Wei
W
Xu
Li
L
Li
Jin-Tian
JT
Chen
Xiao-Jun
XJ
Zhang
Ru-Hua
RH
Xu
Da-Zhi
DZ
D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D004273:DNA, Neoplasm / Q000235:genetics; D005472:Fluorouracil / Q000008:administration & dosage; D006801:Humans; D002955:Leucovorin / Q000008:administration & dosage; D053842:Microsatellite Instability / Q000187:drug effects*; D018895:Microsatellite Repeats / Q000235:genetics; D020360:Neoadjuvant Therapy; D013274:Stomach Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000601:surgery
D004273:DNA, Neoplasm; D002955:Leucovorin; D005472:Fluorouracil