Severe folate deficiency anemia associated with the use of a PARP inhibitor (olaparib) in a patient with fallopian tube cancer

Treatment of cancer patients with olaparib (PARP inhibitor) is associated with an increased risk of anemia, which is seen in a majority of treated patients. However, symptomatic anemia requiring transfusion is rare. Olaparib-induced anemia can be secondary to bone marrow suppression, hemolysis or folate deficiency. We report a case of new onset severe folic acid deficiency anemia in a patient with breast and relapsed fallopian tube cancer being treated with olaparib. Complete blood count on admission showed a hemoglobin of 4.2 g/dl and serum folate was undetectable (< 1.6 ng/ml; reference range 7-31.4 ng/ml). This is the second report of olaparib-induced folate deficiency anemia. She received three units packed red cell transfusion and parenteral folic acid supplementation and improved symptomatically. This case highlights the importance of recognizing folate deficiency as a reversible cause of anemia with PARP inhibitor therapy.