Decreased Erythropoietin Response in Patients with the Anemia of Cancer

TLDR

Patients with solid tumors are often anemic even before they undergo cytotoxic therapy. The study aimed to investigate whether erythropoietin contributes to the anemia of cancer and to evaluate the potential benefit of erythropoietin therapy. Serum immunoreactive erythropoietin levels were measured in 81 anemic solid‑tumor patients using a sensitive radioimmunoassay. Anemic cancer patients had markedly lower erythropoietin than iron‑deficiency controls, lacked the expected inverse hemoglobin–EPO relationship, showed further suppression with chemotherapy, but could restore EPO production with hypoxemia, indicating that inadequate erythropoietin contributes to cancer anemia.

Abstract

Patients with solid tumors are often anemic even before they undergo cytotoxic therapy. Since the cause of the anemia of cancer is unknown, we examined the possible role of erythropoietin. Using a sensitive radioimmunoassay, we determined serum immunoreactive erythropoietin levels in 81 anemic patients with solid tumors. For any given degree of anemia, the serum concentration of immunoreactive erythropoietin was lower in this group of patients than in a group of control patients with iron-deficiency anemia (P = 0.0001). Furthermore, the expected inverse linear relation between serum levels of immunoreactive erythropoietin and of hemoglobin was absent in the group with cancer. The erythropoietin response was further decreased in patients receiving chemotherapy; it was not influenced by the presence or absence of cisplatin in the treatment regimen. The inability of the patients with cancer to produce erythropoietin was not absolute; if they had hypoxemia, adequate erythropoietin production was restored. We conclude that erythropoietin levels are inappropriately low in anemia associated with cancer, and that erythropoietin deficiency may contribute to the development of this form of anemia. Treatment of the anemia of cancer with erythropoietin may be of value.