Objectives: Because of the high prevalence of coexisting medical conditions in patients with gastrointestinal cancer, clinical investigators often need to adjust for comorbidity when assessing the effect of comorbidity on patient outcome. Comorbidity in cancer has been shown to be a major determinant in treatment selection and survival. However, none of the comorbidity studies in patients with gastric cancer reported in the literature have been performed using the Charlson comorbidity index. The purpose of this study was to examine the applicability of the CCI and usefulness of the CCI as a predictor in patients with gastric cancer and to examine whether it correlates with short- term outcome in these patients.
Method: Study design was a prospective study. The study population was drawn from our department and included 139 patients who underwent curative treatment of gastric cancer between 1.1.1997 and 31.12.2001. All patients were staged by the CCI for comorbidity and divided into three groups based on the comorbidity severity staging. Group 1 included patients with no comorbidity, group 2 included those with low-level comorbidity and group 3 those with severe comorbidity. Outcomes were compared based on these divisions performing uni- and multivariate analysis.
Results: 35 patients (25.2 %) had no, 55 (39.6 %) low and 39 (35.2 %) severe comorbidity. 28.8 % of patients showed no or mild, 14.4 % moderate and 14.4 % of patients severe postoperative complications and 5.8 % died in hospital postoperatively. 30-day-mortality was 3.6 % (n = 5). There was no statistical significant correlation between CCI and occurrence of postoperative complications, severity of postoperative course and postoperative stay in hospital. In multivariate analysis only age was an independent factor for postoperative course.
Conclusion: The method of classifying comorbidity by CCI provides a simple, readily applicable and valid method of estimating risk of death from comorbid disease for use in longitudinal studies and in outcomes research from administrative databases. In gastric cancer, however, the CCI was found not to be a valid prognostic indicator.