The IRON GUT study: Identifying the prevalence of iron deficiency anemia in gastrointestinal cancer patients.

277 Background: Few studies have identified the prevalence of iron deficiency/iron deficiency anemia in the population of luminal gastrointestinal (GI) malignancies. The objective of this retrospective study was to assess the prevalence of iron deficiency (ID) and iron deficiency anemia (IDA) in GI cancer patients treated at Mount Sinai Hospital (MSH) in Toronto, Canada. Methods: Between January 2009 and December 2022, 533 luminal GI cancer patient charts were retrospectively reviewed at MSH. Details extracted included demographics, history of IDA, previous IDA therapies, and cancer history. Hemoglobin, mean corpuscular volume and hematocrit were collected at five time points. Transferrin saturation, ferritin, iron serum and iron saturation were collected at pre- and post-chemotherapy initiation. Anemia was defined as having a hemoglobin (Hb) value < 110g/dL in women and < 132g/dL in men. Results: The patient population included 54 gastric, 267 colon, 62 recto-sigmoid, and 150 rectal cancer patients, 75.4% (402/533) of which were anemic at some point during the study period. At pre-chemotherapy initiation, 219 (41.1%) patients were anemic, 65 (12.2%) patients had ferritin and transferrin saturation values assessed; 31 (47.7%) had ID and 25 (38.5%) had IDA. After chemotherapy initiation, 83 (15.6%) patients were assessed for ID; 27 (32.5%) had ID and 19 (22.9%) had IDA. Anemia was treated by parenteral, oral iron or red blood cell transfusion, at least once during or prior to chemotherapy treatment for 186 patients. Conclusions: Despite anemia being prevalent in GI cancer patients where initial diagnoses is often prompted by onset of anemia, only 65 (12.2%) patients were assessed for ID pre-chemotherapy and 34.9% of patients were provided with any form of treatment for anemia during oncologic treatment. Proper repletion needs to occur if ID or IDA is identified, most notably with rapid parenteral iron, especially if embarking on myelosuppressive systemic chemotherapy. Guidelines are essential to ensure proper diagnosis and management of ID and IDA in this cancer patient population.