Analysis of Outcomes and Prognostic Factors Associated with Surgical Treatment Plus Postoperative Radiation Therapy for Stage II/III Pancreatic Cancer

ABSTRACT

PURPOSE: To evaluate treatment outcomes for patients with stage II/III pancreatic cancer who are treated with radiation therapy (RT) with or without chemotherapy (CTx) following surgery. METHODS: We retrospectively analyzed data from 17 patients who underwent surgery and post-operative RT with or without CTx between January 2000 and December 2008. Seven patients (41%) had stage II cancer and 10 (59%) had stage III cancer. Most were male (13 of 17; 76.5%). Age at diagnosis ranged from 42 to 82 (median 69) years. Whipple's operation was done in 9 patients (53%), distal pancreatectomy in 7 (41%), and subtotal pancreatectomy in 1 (6%). All patients received RT using a three-dimensional RT technique to spare critical normal structures. Median radiation dose was 54 Gy (range, 50.4~55.8 Gy). Variable CTx regimens were combined in 10 patients (58.8%); 5-FU in 4, UFTE-G in 4, gemcitabine in 1, and xeloda in 1. Acute toxicity was evaluated according to RTOG toxicity criteria. Survival analysis was done using the Kaplan-Meyer method. Univariate and multivariate prognostic factor analysis were done, respectively, using a log-rank test and Cox's proportional hazards model. RESULTS: The median follow-up period was 12.6 months. Locoregional and distant failures occurred in 8 (47.1%) and 8 patients (47.1%), respectively. Five patients (29.4%) developed both loco-regional recurrence and distant metastasis. The metastatic sites were liver in 4 patients, lung in 3, peritoneum in 1, and kidney in 1. Median overall survival (OS) was 12.6 months. The 1- and 2-year OS rates were, respectively, 58.8% and 24.5%. Median disease-free survival (DFS) was 8.3 months and the 1- and 2-year DFS rates were 46.3% and 30.9%, respectively. The 2-year OS was not different between RT and RT with CTx : survival rates were 28.6% and 17.5%, respectively (p=0.764). T stage and a postoperative CA 19-9 level of > or =180 U/ml were significant prognostic factors for OS in both univariate and multivariate analysis: the 2-year OS for T3 and T4 were 34.1% and 16.7%, respectively (p=0.0022), the 2-year OS for or =180 U/ml were 32.5% and 0%, respectively (p=0.0142) Acute toxicities were RTOG grade 1 (G1) nausea in 1 patient (5.9%), G1 vomiting in 2 (11.8%), and G1-2 enteritis in 5 (29.4%). The hematologic toxicities were G1 leukopenia in 5 patients (29.4%), G2 leukopenia 1 (5.9%), G1 thrombocytopenia in 1 (5.9%), and G1~2 anemia in 6 (35.3%). CONCLUSION: Survival results of the present study are comparable to those in other reports with acceptable toxicity. Significant prognostic factors for overall survival in pancreatic cancer are tumor stage and postoperative CA 19-9 level.