Long-term survival and prognostic indicators in small (≤2 cm) pancreatic cancer

Objectives: In a matched analysis, we investigated clinical, histopathological, and survival characteristics of small (≤2 cm) pancreatic cancer (PaC) as compared to large PaC. Methods: From the Mayo pathology database, we identified 41 consecutive patients with small PaC and 94 matched controls with margin-negative PaC >2 cm. Two experienced pathologists, who were blinded to survival data, independently reviewed tumor stage and differentiation. Kaplan-Meier survival analysis and Cox proportional hazards models were applied for data analyses. Results: In patients with localized disease (stages I and II), survival was similar in small and large PaC but survival was significantly better in small PaC with regional nodal metastasis (stage III) as compared to similar stage large PaC (5-year survival 44 vs. 7%, median survival 58 vs.18 months, p < 0.001). Well-differentiated small and large PaC had similar median survival (76 vs. 74 months, p = NS). In multivariate analysis, tumor differentiation, not tumor size, was the only independent factor predicting survival in PaC (risk ratio, RR, for moderate vs. well- differentiated: 2.6, 95% confidence interval, CI, 1.5-4.5, and RR for poorly differentiated vs. well-differentiated: 5.0, 95% CI 2.4-10.1). Conclusion: Tumor differentiation may be a better predictor of survival in resectable PaC than tumor stage.