Uric Acid as a Prognostic Factor for Survival Time: A Prospective Cohort Study of Terminally Ill Cancer Patients

Abstract

The aim of this prospective cohort study was to determine whether serum uric acid level is useful as a predictor of survival in terminally ill cancer patients. One hundred eighteen terminally ill cancer patients, including 63 (53.4%) males, were categorized into four groups by serum uric acid levels and followed up until death or to the end of the study. Cox's proportional hazard model was adopted to evaluate the joint effect of some clinicobiological variables on survival. From an initial model containing 51 variables, a final parsimonious model was obtained by means of a stepwise method. Repetitive dispersion analysis was performed for serum uric acid level in 39 subjects for 3 weeks until death. During the study period, 113 (95.76%) subjects expired, and the median survival time was 14 days. In univariate analysis, survival time of the fourth highest group (≥7.2 mg/dL) was significantly shorter than that of the others (hazard ratio (HR) = 2.784, P < 0.001). After adjustment for low performance status, moderate to severe pain, prolonged prothrombin time, hypocholesterolemia, and high lactate dehydrogenase (LDH) level, high serum uric acid level (≥7.2 mg/dL) was significantly and independently associated with short survival time (HR = 2.637, P = 0.001). Serum uric acid levels were also significantly increased between the first and the second week before death. These findings suggest that serum uric acid level can be useful in predicting life expectancy in terminally ill cancer patients.