Tumor burden index as a prognostic tool for cutaneous T-cell lymphoma - A new concept

Objectives: To introduce a prognostic tool for cutaneous T-cell. lymphoma t hat takes into account the tumor burden and to compare the prognostic value of this tumor burden index (TBI) with that of other prognostic factors. Design: Retrospective clinical and statistical study. Patients: One hundred sixteen patients with cutaneous T-cell lymphoma. Methods: A TBI was designed that takes into account the types, numbers, and severity of skin lesions with the use of the Got: proportional hazard mode l. Results: Models of the TBI were developed to test the relative contribution s of patches, plaques, and tumors to the total tumor burden and, hence, sur vival time. Weighting factors reflecting the severity of each skin lesion w ere tested and incorporated. The best prognostic correlation was a dichotom ized index with the following formula. TBI = 1 + (patchcs x 2) + (plaques x 2) + (tumor x 1.3),where the patches Factor equals 0 if 30% or less of the skin area is involved and 1 if greater than 30% of the skin area is involv ed and where the plaque or tumor factor equals 1 if plaques or tumors are p resent, Both the TBI and TNM provided predictive information. Discriminatio n of survival curves and significance of differences was better for TBI (P < .001) than for TNM (P = .009). Sex was also statistically related to surv ival (males had a better prognosis, P < .04), whereas neither age at first symptoms (P = .35) nor age at time of diagnosis (P = .36) was of prognostic value. Conclusions: The TBI offers a simple prognostic index for the evaluation of cutaneous T-cell lymphoma. It mall become a valuable tool for designing th erapeutic strategies for patients according to their specific survival expe ctancies. However, this model is preliminary and has to be validated on a l arger number of patients.