Conditional survival of esophageal cancer: An analysis from the SEER registry (1988-2011)

Introduction: Conditional survival can provide valuable predictive information for both patients and caregivers for patients surviving over time. The purpose of this study was to estimate conditional survival for esophageal cancer patients through analysis of a national population-based cancer registry. Methods: This retrospective cohort study analyzed 64,433 patients within the Surveillance, Epidemiology, and End Results (SEER) data set who were diagnosed with esophageal cancer from 1988 to 2011. Covariates included cancer characteristics and demographics. Overall survival (defined as time from diagnosis until death), causespecific survival (defined as time from diagnosis until death from cancer), and 5-year conditional survivals (the probability of surviving an additional 5 years) were calculated. Significant prognostic variables of univariate and multivariable models of survival were identified. Results: The multivariable models of overall and cause-specific survivals included gender, age group, race, relationship status, year of diagnosis, site, grade, histology, and stage group. Although all patients showed an improvement in conditional survival over time, more dramatic improvements were seen in more advanced stage groups. At the 5-year mark, conditional cause-specific survival of distant stage (defined as having spread by direct extension or metastasis to distant organs, tissues, or lymph nodes) increased from 4% to 79%, whereas regional stage increased from 18% to 77% and localized stage increased from 38% to 85%. Conclusions: Conditional survival showed improving prognosis over time. Patients with advanced stage had the most dramatic improvement. Clinicians, caregivers, and patients with esophageal cancer can feel encouraged by the improving prognosis with each year survived. This information has practical implications regarding longitudinal follow-up guidelines and survivorship planning.