N. Poulsen1, S. Patil1, R. S. Chamberlain1 2Saint George’s University,Grenada, Grenada, Grenada 1Saint Barnabas Medical Center,Surgery,Livingston, NJ, USA
Introduction: Pancreatic ductal adenocarcinoma (PDC) makes up more than 90% of pancreatic tumors; however, other less common histological subtypes exist including acinar cell carcinoma (ACC), islet cell tumors (IC), neuroendocrine tumors (NE) and squamous cell carcinoma (SCC). While information on the clinical course, management and outcomes associated with adenocarcinoma of the pancreas has been extensively studied, information on other histological subtypes is limited.
Methods: Data on 100,727 patients with pancreatic cancer from the Surveillance Epidemiology and End Results (SEER) database (1973- 2008) was abstracted. Patients with PDC, ACC, IT, NE, and SCC were separately analyzed for age, gender, race, stage, treatment, and long-term survival. Categorical variables were compared using the Chi square test, and continuous variables were compared using ANOVA.
Results: PDC (N=95,271; 94.6%) was the most common form of pancreatic cancer identified followed by NE (N=2,922; 2.90%), IC (N=1,845; 1.83%), SCC (N=355; 0.34%) and ACC tumors (N=334; 0.33%). Pancreatic cancer occurs most commonly in Caucasian men in the 6th decade of life, however patients with IC tumors and NE tumors were significantly younger than those with PDC, ACC and SCC. All five subtypes presented most commonly with metastatic disease (PDC: 57.2%; ACC: 48.8%; IC: 48.3%; NE: 60.8%; and SCC: 60.0%). Overall survival was 1.43 years. Patients with IC tumors had the greatest mean survival (5.08 years), followed by NE tumors (2.96 years), ACC (2.79 years), and PDC/SCC (1.31 years each) (p< 0.001). Mortality was significantly greater in patients with SCC and PDC (96.3% and 93.9% respectively, p<0.001) compared to all other subtypes. Combination surgery and radiation therapy demonstrates the greatest 5- and 10-year survival rate in patients with PDC (19% and 10%), ACC (54% and 37%), and SCC (25% and 13%) (p<0.001). Surgical intervention alone demonstrates the greatest 5- and 10-year survival in IC tumors (74% and 56%) and NE tumors (76% and 58%) (p< 0.001). PDC and SCC had the lowest 5- and 10-year survival for all treatment modalities.
Conclusion: Pancreatic cancer is a devastating disease with an overall mortality greater than 65% independent of histological subtype. PDC and SCC demonstrate the lowest mean survival, highest mortality and appear to follow a similar clinical course independent of treatment modality. Despite an overall mortality rate of 66% and a mean survival of 5 years, pancreatic IC tumors are the most indolent pancreatic tumors. Surgical intervention appears to offer the greatest survival benefit to patients with IC and NE tumors, while combined surgical and radiation therapy appears to offer the greatest survival benefit to patients with PDC, SCC and ACC.
