Trends in survival after colorectal cancer surgery in an Australian regional hospital

Abstract

Background: Colorectal cancer (CRC) is the second most common cancer in Australia. Improvements in patient outcomes after resections for CRC have been reported in an Australian metropolitan hospital, but significant outcome variability exists between health systems and institutions. Objective: This study sought to determine whether changes in the management of CRC have translated into improved survival after surgery in an Australian regional hospital. Design: This is a retrospective study of a prospectively maintained database. Setting: This study was conducted in an Australian regional hospital. Patients and Methods: All patients who underwent surgery for CRC at our institution between January 2002 and December 2014 were studied. Demographic information, comorbidities, types of surgery performed, and tumor staging were recorded. Patients were followed up for life whenever possible. Survival analysis was done using the Kaplan–Meier method, and comparisons made using the Cox proportional-hazards method. Chi-squared test was used to compare categorical data and look at trends as appropriate. P ≤ 0.05 was considered statistically significant. Statistical analysis was done using Medcalc® (Mariakerke, Belgium) software. Main Outcome Measures: Primary outcome measures the survival trends for CRC patients in regional center, Victoria. Secondary outcomes measure the short-term results, including perioperative mortality and anastomotic leak rate. Sample Size: A total of 1079 patients who underwent surgery for CRC over 13 years were studied. Results: There were 744 colon cancer and 335 rectal cancer patients. The number of operations per year increased over time (P = 0.037). The median age was 72 years (range, 23–98) and this did not change over time (P = 0.67). There was also no temporal change in tumor stage distribution (P = 0.21) or in the proportion of emergency cases (P = 0.75), but the proportion of patients with severe comorbidities increased (P = 0.015). The perioperative mortality rate was 4.5%. The median survival after surgery by stage was 123 months (Stage I), 141 months (Stage II), 76 months (Stage III), and 17 months (Stage IV tumors). Over the study period, there were improvements in both perioperative mortality (P = 0.028) and long-term survival (P = 0.0025). Conclusion: Both short- and long-term survivals after surgery for CRC have improved in our institution. Limitation: Although a large regional cohort was analyzed, the study still has its own limitation, in that it is a retrospective single institute study.