Variables predictive of bone marrow metastasis.

Metastasis to bone marrow, though frequently occult, is an important clinical finding. Variables which correlate with carcinoma metastatic to bone marrow were studied retrospectively in 103 patients with malignancy whose bone marrow biopsies demonstrated metastatic disease. Sixty-six patients with metastatic cancer whose bone marrow biopsies were negative, served as controls. Since no single finding was diagnostic of marrow cancer, multiple variables were analyzed by stepwise discriminate analysis program. The four parameters which strongly correlated with marrow involvement were the leukoerythroblastic blood pattern, a serum lactic dehydrogenase over 500 IU/liter, a platelet count under 100,000/microliter and bone pain. Four parameters correlated less well and included a positive bone scan, hematocrit under 30%, uric acid over 10 mg/dl and blood urea nitrogen over 25 mg/dl. These data should help the clinician select those cancer patients with a high probability of marrow involvement.