The prognostic role of HBV infection in chronic lymphocytic leukemia.

PURPOSE

We attempt to assess the impact of hepatis-B virus (HBV) status on the prognosis of chronic lymphocytic leukemia (CLL) using a Chinese case cohort.

METHODS

Five hundred and one consecutive newly diagnosed subjects with CLL were enrolled in this case cohort. HBV infection was defined as hepatitis B surface antigen (HBsAg) positive or hepatitis-B core antibody (HBcAb) positive. Univariate and stepwise multivariate Cox regression analyses were used to screen the prognostic risk factors associated with the end point of time-to-treatment (TTT) or overall survival (OS). Bootstrap re-sampling method was used to evaluate the model's internal validity. The discriminative ability of the models was evaluated using time-dependent receiver-operator characteristic (ROC) curves and corresponding areas under the curve (AUC).

RESULTS

One hundred and twenty-one subjects (24%) among 501 patients were HBV positive. HBV infection was an independent predictor for the prognosis of TTT (HR = 1.37; 95% CI 1.04-1.80) or OS (HR =2.85; 95% CI 1.80-4.52). The AUCs for HBV infection were 0.62 (95% CI 0.58-0.66) for TTT and 0.69 (95% CI 0.66-0.72) for OS, respectively. When we combined HBV infection with the traditional clinical and biological factors, significant improvements for model's discrimination were observed for TTT [AUC: 0.81 (95% CI: 0.77-0.85) vs. 0.78 (95% CI: 0.74-0.82), P < 0.001] and OS [AUC: 0.81 (95% CI 0.76-0.86) vs. 0.76 (95% CI 0.71-0.82), P < 0.001). Further bootstrap re-sampling method revealed good internal consistence for the final optimal models (Average AUC: 0.78 for TTT and 0.79 for OS based on 1000 bootstraps).

CONCLUSIONS

Our results indicated that HBV infection should be served as an important risk predictor for prognosis of CLL (TTT and OS).