Objective To assess the prostaglandin E

2

(PGE

2

) levels in tumor mass and peripheral blood of patients with gastric cancer and explore their clinical significance.  Methods The PGE

2

levels in tumor mass

tumor margins of excision and peripheral blood of 40 patients with gastric cancer were measured by a ki

t of PGE

2

ELISA.  Results The PGE

2

levels were higher in the tissues of gastric cancer than in tumor margins of excision [(8.225±2.425) vs (1.669±0.287) ng/g，P0.01

]

. The PGE

2

levels in tissues of low and midhigh differentiation cancer were (9.02±2.28) and (5.38±0.35) ng/g respectively

with statistically significance (P0.05). The PGE

2

levels in peripheral blood was positively correlated to that in tissue of gastric cancer (r=0.889，P0.01). Peripheral blood PGE

2

level was statistically higher in the tumor more than 5 cm in size than in that less than 5 cm (P0.05)

which were (121.15±38.31) and (78.48±23.76) pg/ml respectively. Statistically significance was observed in the PGE

2

levels in peripheral blood between low and midhigh differentiation gastric cancers [(115.5±39.17) vs (73.28±17.68) pg/ml

P0.05

]

. There was no significant correlation between different ages

different sexes

site of tumor

depth of invasion

clinopathological type or lymph node involvement.  Conclusion The PGE

2

levels in tumor mass and peripheral blood of patients with gastric cancer are elevated

indicating a positive correlation of the levels in two samples. Peripheral blood PGE

2

level might be used to evaluate the size and differentiation of tumor. gastric cancer.