Characteristics of 10-Year Survivors of Pancreatic Ductal Adenocarcinoma

Abstract

Importance: To our knowledge, this study reports on the largest cohort of long-term survivors (LTSs) (≥10 years) following a diagnosis of pancreatic ductal adenocarcinoma (PADC) and identifies the characteristics associated with LTS.

Objective: To determine patient, tumor, surgical, and sociodemographic characteristics associated with LTS.

Design, setting, and participants: A nationwide retrospective cohort study of patients with invasive PADC (International Classification of Diseases for Oncology, Third Edition codes 8140/3, 8500/3, 8021/3, and 8035/3) was conducted using data collected in the National Cancer Database (NCDB). A multivariable logistic regression model of factors significantly associated with LTS was developed and used to generate a nomogram predicting the likelihood of surviving at least 10 years from initial diagnosis. Data collected from more than 1500 academic centers and community hospitals in the United States and Puerto Rico were assessed. Patients included were those with histologically proven PADC who underwent pancreatic surgical resection aimed at removal of the primary tumor between January 1, 1998, and December 31, 2002 (n = 11,917). The initial cohort (n = 70,915) excluded noninvasive tumors or tumors with unknown histology (n = 11,696) and was limited to patients who underwent surgical resection (n = 47,302 excluded). Analysis was conducted from January 1, 1998, to December 31, 2011.

Exposures: Pancreatic ductal adenocarcinoma.

Main outcomes and measures: Long-term survival, defined as surviving at least 10 years from initial diagnosis.

Results: Of the 11,081 patients with complete survival information, 431 individuals (3.9%) were LTSs. Significant predictors of LTS included (determined using odds ratio [OR]; 95% CI), in order of importance, lymph node positivity ratio (0%: 4.6; 3.4-6.4), adjuvant chemotherapy (2.4; 2.0-3.0), pathologic T stage (T1: 3.1; 1.8-5.6), patient age (50-60 years: 3.4; 1.8-6.7), tumor grade (well differentiated: 2.2; 1.5-3.0), surgical margin (negative: 1.9; 1.4-2.6), pathologic M stage (M = X: 5.6; 2.1-22.8), tumor size (<2 cm: 1.7; 1.2-2.5), educational level (>86% high school graduates: 1.7; 1.2-2.4), and insurance status according to the patient's zip code (private: 2.0; 95% CI, 0.9-5.1). The model C index was 0.768. Based on our nomogram, patients with the most favorable characteristics had an 18.1% chance of LTS. Furthermore, survival curves demonstrated that the probability of dying following initial diagnosis of PADC reached a plateau of approximately 10% per year after 7 years of survival.

Conclusions and relevance: Although PADC remains a deadly disease, long-term survival is possible, even beyond the 10-year mark. Our adjusted analysis identified lymph node ratio, administration of adjuvant chemotherapy, and pathologic T stage as being the top 3 variables associated with LTS of PADC. In addition, our easy-to-use nomogram may be able to identify potential LTS among patients with resected PADC.