Inhibition of erythroid colony growth in vitro by serum from patients with disseminated bronchial cancer.

The anemia of malignancy is characterized by a reduced output of erythroid cells but with a normal red cell survival. In this study, clonal assays of normal human marrows in the presence of serum from 13 patients with bronchial cancer gave significantly reduced yields of erythroid colonies compared with control cultures with normal serum. More than half the cultures showed no growth of either CFU-E or BFU-E. Four sera producing marked depression of erythroid colony growth had no effect on CFU-GM. The evidence suggests the presence of a circulating inhibitor that may be found in either anemic or nonanemic patients.