Abstract
Gemcitabine therapy has been the standard first-line treatment for patients with unresectable local cancer. However 1-year survival rates of less than 20% have been reported. Therefore, these results are unsatisfactory and also the prognostic factors are still not sufficiently discussed. We retrospectively analyzed the medical records of 88 patients who received gemcitabine mono-therapy for unresectable pancreatic cancer. The patient characteristics and treatment factors that may be associated with the survival as a patient’s prognosis were investigated. The prognostic factors for survival were examined by univariate and multivariate analyses using the log-rank test and Cox proportional hazard analysis, respectively. Multivariate analysis identified gemcitabine total dose (≤ 9075 mg; hazard ratio HR, 3.10; P = 0.001), absence of second-line therapy (HR, 6.30; P < 0.001), stage IV-b (HR, 4.97; P = 0.005), neutrophil counts (> 3979.5 /μL; HR, 3.43; P = 0.003), lymphocyte counts (≤ 1155.5 /μL; HR, 2.94; P = 0.010), and carcinoembryonic antigen (CEA) levels (> 5.95 ng/mL; HR, 2.57; P = 0.034) as prognostic factors. We conducted additional data analysis including treatment regimens, because second-line chemotherapy is one of the prognostic factors. As indicated by the multivariate analysis, S-1 and gemcitabine combination therapy, S-1 and cisplatin combination therapy, and concurrent gemcitabineradiation therapy were not statistically significant when S-1 mono-therapy was the reference arm. In other words, S-1 mono-therapy is equivalent in efficacy when compared to other combination therapy. These prognostic factors could help to select treatment for patients in clinical practice, and these risk-adapted treatment strategies should be further investigated in a prospective study.
