The effect of depression on stage at diagnosis, treatment, and survival in pancreatic adenocarcinoma

Background: Depression has been associated with delayed presentation, inadequate treatment, and poor survival in patients with cancer. Methods: Using Surveillance, Epidemiology and End Results and Medicare linked data (1992-2005), we identified patients with pancreatic adenocarcinoma (N = 23,745). International Classification of Diseases, 9th edition, Clinical Modification codes were used to evaluate depression during the 3 to 27 months before the diagnosis of cancer. The effect of depression on receipt of therapy and survival was evaluated in univariate and multivariate models. Results: Of patients with pancreatic cancer in our study, 7.9% had a diagnosis of depression (N = 1,868). Depression was associated with increased age, female sex, white race, single or widowed status, and advanced stage disease (P <.0001). In an adjusted model, patients with locoregional disease and depression had 37% lower odds of undergoing surgical resection (odds ratio, 0.63; 95% confidence interval, 0.52-0.76). In patients with locoregional disease, depression was associated with lower 2-year survival (hazard ratio, 1.20; 95% confidence interval, 1.09-1.32). After adjusting for surgical resection, this association was attenuated (hazard ratio, 1.14; 95% confidence interval, 1.04-1.26). In patients who underwent surgical resection, depression was a significant predictor of survival (hazard ratio, 1.34; 95% confidence interval, 1.04-1.73). Patients with distant disease and depression had 21% lower odds of receiving chemotherapy (odds ratio, 0.79; 95% confidence interval, 0.70-0.90). After adjusting for chemotherapy for distant disease, depression was no longer a significant predictor of survival (hazard ratio, 1.03; 95% confidence interval, 0.97-1.09). Conclusion: The decreased survival associated with depression appears to be mediated by a lower likelihood of appropriate treatment in depressed patients. Accurate recognition and treatment of pancreatic cancer patients with depression may improve treatment rates and survival.