Prognostic significance of serum lactate dehydrogenase in malignant lymphoma.

The pretreatment serum lactate dehydrogenase level (LDH) was the single most important prognostic variable in 30 patients with diffuse histiocytic lymphoma treated between January 1973 and January 1977 with a poly-drug chemotherapy program called the cyclophosphamide L2 protocol at the Memorial Sloan-Kettering Cancer Center. A highly significant difference was found between the survival patterns of patients with LDH levels of 500 U or less and those with LDH levels greater than 500 U. (Two-year survival rates were 67% and 13%, respectively.) A similar trend was observed for 25 patients with diffuse, poorly differentiated lymphocytic lymphoma treated with the same protocol, although this difference was not statistically significant. (Corresponding two-year survival rates were 74% and 33%, respectively.) The association of LDH level with survival was evident even after adjustment for other factors of potential prognostic significance. Pretreatment serum LDH determinations may provide a useful means of stratifying patient populations when comparing treatment programs for advanced stage non-Hodgkin's lymphoma.