Abstract
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Background: Oldfield et al (2015) showed the conflicting evidence regarding the effect of adjuvant chemotherapy vs. chemoradiation in pancreatic cancer. Using patients identified by the National Cancer Database (NCDB), we are the largest study to compare survival in stage II pancreatic cancer patients who received adjuvant chemotherapy, chemoradiation, radiation, or no adjuvant therapy. Methods: We identified 65,091 patients with stage II pancreatic cancer who received surgery only or surgery in combination with chemotherapy, radiation, or chemoradiation. Between-therapy survival differences were estimated by the Kaplan-Meier method and associated log-rank tests; Tukey-Kramer adjusted p < .05 indicated statistical significance. Results: Patient characteristics were similar between groups; although, patients receiving chemoradiation were younger, had fewer comorbidities, and were more likely to have private insurance compared to all other therapy groups. Statistically significant survival differences were indicated between all therapy groups (all adjusted p< 0.05), as patients receiving chemoradiation had the longest survival followed by patients receiving chemotherapy, patients receiving radiation therapy, and patients receiving no adjuvant therapy (median survival = 22.5, 19.6, 16.9, 14.8 months, respectively). When examining other variables, patients living in an area with a median income < $43,000 were 14% more likely to die compared to patients in an area with a median income ≥ $63,000 (p < 0.001) and those with no comorbidities were 19% less likely to die than patients with two or more comorbidities (p < 0.001). Conclusions: Our data suggests that adjuvant therapy improves median and 3-year survival compared to no adjuvant therapy. Of all adjuvant therapies examined, adjuvant chemoradiation was associated with the greatest increase in survival, followed by adjuvant chemotherapy. Table 1: Median survival and survival rates of stage II pancreatic cancer [Table: see text]