Lactate dehydrogenase values and bone scans as predictors of bone marrow involvement in small-cell lung cancer.

The value of serum lactate dehydrogenase (LDH) levels and bone scan results in predicting marrow involvement in small-cell carcinoma of the lung (SCCL) was studied. Records of 79 patients with SCCL who had undergone 92 bone marrow examinations were reviewed. None of 25 patients with marrow involvement had a normal LDH and a negative bone scan, compared with 23 of 59 in the uninvolved group. We conclude that patients with SCCL with both negative bone scans and normal LDH values have a less than 5% chance of marrow involvement.