OBJECTIVETo investigate whether CK20 mRNA expression level could be considered as an effective molecular indicator for evaluation of chemotherapy sensitivity.

METHODSAll samples of peripheral blood were taken from 31 gastric cancer patients undergone radical operation a week before postoperative chemotherapy, at the first day of chemotherapy point, and after the first cycle of chemotherapy respectively, and subjected to FQ RT-PCR assay for CK20 mRNA. The chemotherapy scheme was FOLFOX 4. The control group was 15 healthy volunteers.

RESULTSAomng the 31 gastric cancer patients, the value of CK20 mRNA before postoperative chemotherapy was increased (2.96+/-2.27 vs 2.22+/-2.12, t=2.10, P<0.05) in 25 positive cases, and then declined after chemotherapy(2.05+/-1.86 vs 2.96+/-2.27, t=2.50, P<0.05) in 24 positive cases. The expression level of CK20 mRNA in patients before chemotherapy was increased in 16 cases(51.6%), declined in 9 cases(29.0%) and stabilized as negative in 6 cases(19.4%). After chemotherapy the level of CK20 mRNA was increased in 7 cases(22.6%), declined in 17 cases (54.8%) and stabilized as negative in 7 cases(22.6%), there was significant difference between the two groups(chi(2)=6.06, P<0.05).

CONCLUSIONSThe expression level of CK20 mRNA in the peripheral blood detected by FQ RT-PCR in patients with gastric cancer declines after postoperative adjuvant chemotherapy. Different individuals have different sensitivity to chemotherapeutics. Dynamic monitoring CK20 mRNA should be considered as an effective index to evaluate the efficacy of postoperative adjuvant chemotherapy.