Figure 1.

The expression of sphingosine kinase 1 (SphK1) in human colon adenocarcinomas correlates with advanced disease and poor survival. (a) Immunohistochemistry staining of SphK1 was carried out in 303 tumor tissues. SphK1 expression was tabulated using the four-tier scoring system (0, 1+, 2+, 3+). SphK1 expression was classified as absent/undetectable (0) or present (1+, 2+, 3+). (b) Competing risk regression model taking into account disease recurrence. The probability of mortality within 5 years was 37% in patients with detectable SphK1 expression, and the probability of mortality within 5 years was 7% in patients with undetectable SphK1 expression. Both probabilities take into account the probability that recurrence status could occur instead. (c) Competing risk regression model taking into account death due to colon cancer. The probability of having a recurrence within 5 years was 23% in patients with detectable SphK1 expression, and the probability of mortality within 5 years was 28% in patients with undetectable SphK1 expression. Both probabilities take into account the probability that the death could occur instead. (d, e) Kaplan–Meier cumulative incidence estimates of mortality and recurrence, respectively.