VALIDATION OF THE CHARLSON COMORBIDITY INDEX IN PATIENTS WITH HEAD AND NECK-CANCER - A MULTIINSTITUTIONAL STUDY

Comorbid conditions are medical illnesses that accompany cancer, The i mpact of these conditions on the outcome of patients with head and nec k cancer is well established However, all of the comorbidity studies i n patients with head and neck cancer reported in the literature have b een performed using the Kaplan-Feinstein index (KFI), which may be too complicated for routine use. This study was performed to introduce an d validate the use of the Charlson comorbidity index (CI) in patients with head and neck cancer and to compare it with the Kaplan-Feinstein comorbidity index for accuracy and ease of use, Study design was a ret rospective cohort study, The study population was drawn for three acad emic tertiary care centers and included 88 patients 45 years of age an d under who underwent curative treatment for head and neck cancer, All patients were staged by the KFI and the CI for comorbidity and divide d into two groups based on the comorbidity severity staging, Group 1 i ncluded patients with advanced comorbidity (stages 2 or 3), and group 2 included those with low-level comorbidity (stages 0 or 1). Outcomes were compared based on these divisions. The KFI was successfully appli ed to 80% of this study population, and the CI was successfully applie d in all cases (P < 0.0001). In addition, the KFI was found to be more difficult to use than the CI (P < 0.0001). However, both indices inde pendently predicted the tumor-specific survival (P = 0.007), even afte r adjusting for the confounding effects of TNM stage by multivariate a nalysis. Overall, the CI was found to be a valid prognostic indicator in patients with head and neck cancer. In addition, because comorbidit y staging by the GI independently predicted survival, was easier to us e, and more readily applied, it may be better suited for use for retro spective comorbidity studies.