Background and objective: Gemcitabine is used as an effective drug for patients with advanced pancreatic cancer. Serum CA19-9 has been proven as the most sensitive and specific serum marker for pancreatic cancer. This study was to investigate the value of serum CA19-9 in evaluating treatment efficacy and predicting prognosis of patients with pancreatic cancer treated by gemcitabine-based chemotherapy.
Methods: Seventy-one patients with histologically confirmed, locally advanced or metastatic pancreatic adenocarcinoma, whose karnofsky's performance status (KPS) score was >or= 70 were treated with gemcitabine alone or with gemcitabine-based chemotherapy. CA19-9 was measured before and after chemotherapy.
Results: Ten out of 71 patients had normal baseline CA19-9 levels, and 61 patients had increased baseline CA19-9 levels. The overall survival of patients were similar between the two groups, which were 9.0 months and 7.9 months respectively (P=0.797). The median baseline CA19-9 level for patients who had increased CA19-9 was (682+/-558) U/mL before treatment. Patients whose pretreatment CA19-9 levels were <682 U/mL achieved better survival than those whose pretreatment CA19-9 levels were >or=682 U/mL (9.6 months vs. 5.1 months, p=0.001). In addition, patients with a pretreatment CA19-9 level of <682 U/mL also had a better tumor response (43.5% vs. 15.8%, p=0.051) and clinical benefit response (48.1% vs. 29.2%, P=0.125) than those whose pretreatment CA19-9 level was <682 U/mL, but the differences were not significant. Patients with a fall of >or=25% in the baseline CA19-9 level after chemotherapy achieved a longer median overall survival (10.2 months vs. 5.0 months, p<0.001), better tumor response (47.8% vs. 10.5%, p=0.002) and better clinical benefit response (69.2% vs. 8.0%, P=0.000) than those without a decrease of baseline CA19-9 or with a fall of <25%. Multivariate analysis revealed that the baseline CA19-9 level before chemotherapy, decreased percentage of the CA19-9 level after chemotherapy, and the differentiation degree of tumor cells were independent risk factors for patients whose baseline CA19-9 levels were increased.
Conclusion: The level of pretreatment base-line CA19-9 and the decreased percentage of baseline CA19-9 level after chemotherapy are of predictive values for survival of patients with advanced pancreatic cancer undergoing gemcitabine-based chemotherapy and with an increased level of baseline CA19-9.