Serum soluble CD27, but not thymidine kinase, is an independent prognostic factor for outcome in indolent non-Hodgkin's lymphoma

Non-Hodgkin's lymphoma (NHL) forms a heterogeneous group of diseases. Tumor markers may help to identify high-risk patients who might benefit from more aggressive therapy. Serum soluble CD27 (sCD27) and thymidine kinase (TK) are potentially valuable markers, since sCD27 has previously been shown to be related to tumor load and TK to proliferation of malignant cells. We determined serum sCD27, TK, beta-2-microglobulin (beta(2)M) and lactic dehydrogenase (LD) levels at diagnosis in 79 lymphoma patients and correlated these parameters with the stage of disease, the International Prognostic Index (IPI) score and survival. Receiver operator characteristic (ROC) curve analysis showed an excellent ability for sCD27 to discriminate between low- and high-stage disease (p < 0.001), especially in indolent lymphomas. No discriminative value for TK, beta(2)M or LD was found. For aggressive NHL, sCD27, TK, beta(2)M and LD did predict survival in the univariate analyses. However, LD was found to be the most independent prognostic factor in a multivariate Cox regression model. In indolent lymphomas, sCD27 proved to be a powerful marker to predict progression-free survival (p = 0.008). Taken together, the results of the ROC curve and survival analysis suggest that substitution of LD by sCD27 in the IPI may be considered for indolent lymphomas to enhance the prognostic value. A study in a larger cohort of patients is required to validate this approach.