Proximal Lesions and Colon Cancers in Iron Deficiency Anemia

Abstract

Introduction: Distal colorectal cancers (cancers distal to the splenic flexure) are more common than proximal cancers (cancers proximal to the splenic flexure) until about age 70, when proximal cancers begin to outnumber distal cancers. But there is a slight preponderance of proximal colon cancers in African American. We hypothesized that the more patient with identifiable lesions in proximal colon will have colon cancers, during work up for iron deficiency anemia (IDA) in African American. Methods: Patients referred for endoscopic evaluation for IDA (defined by hemoglobin ≤ 12 g/dl in females and ≤13 g/dl in males, and ferritin ≤ 45 ng/mL or transferrin saturation ≤ 15%) were included in the study. Patients with excessive menstrual bleeding, pregnant patients, history of blood donation, other causes for anemia, prisoners, or those with a history of gastrointestinal surgery were excluded. Eligible patients were assigned to two groups: Patients with endoscopic findings on proximal colon and patients with endoscopic findings on distal colon. Malignancy, ulcer/erosion, multiple AVM's, colitis, and adenoma > 1 cm were considered to be a positive GI lesion. Logistic regression analysis was performed using proximal colon cancer as a predictor variable in patients of both groups. Results: From January 2005 to December 2007, 495 consecutive patients were referred for IDA work up and 238 patients met inclusion criteria. There were 41 IDA patients who were positive GI lesion in colon. Demographic and clinical characteristics were similar in both groups. (Table 1)Table 1: Demographic and clinical characteristicsEndoscopic finding on proximal colon in IDA patient were significantly more likely to have been a cancer than finding on distal colon. (86.59 % vs 50.00 %, p=0.01). Conclusion: African American patient with IDA, identifiable proximal colon lesions were significantly more likely to have been a cancer than distal lesions.