Anemia-Related Red Flags as Distinctive Early Indicators for Colorectal Cancer Diagnosis in Older Adults

Background: Anemia is an important clinical sign which often points to a serious and possibly treatable medical condition. We aimed to investigate the frequency of anemia long before colorectal cancer (CRC) surgeries among older adults aged ≥ 75 years (group 2), compared to patients aged 50-75 years (group 1). Participants and setting: Consecutive patients operated for CRC in our center who belonged to the health maintenance organization (HMO) at least 36 months before their diagnosis were included. Methods: Laboratory data were extracted from the HMO database. Anemia and severe anemia were defined as Hb < 14 g/dL and <12 g/dL for males and <12 g/dL and <10 g/dL for females, respectively. Low serum iron was defined as below 45 mcg/dL. Results: 647 patients were identified, including 277 (42.8%) ≥75 years (mean age 80.7 ± 4.1 y) and 370 (57.1%), aged 50-75 years (mean 65.8 ± 6.5 y). CRC was more commonly diagnosed following a presentation of iron deficiency anemia in group 2 (20.6% vs. 11.6%, p = 0.002), while positive fecal occult blood test was more frequent among the younger group. Anemia and severe anemia ≥ 1 year before CRC diagnosis were observed in 156 (56.3%) and 56 (20.2%) patients of group 2 compared to 142 (38.4%) and 38 (10.3%) of patients from group 1 (p < 0.001 and p = 0.001, respectively). A low iron level ≥ 1 year before diagnosis was observed in 49 (17.6%) patients in group 2 compared to 35 (9.5%) of group 1 (p = 0.007). Conclusions: More than 50% of older adults aged ≥ 75 years, diagnosed with CRC had evidence of anemia, at least 1 year before cancer diagnosis. Health policymakers should educate physicians about the importance of recognizing abnormal laboratory results, such as anemia, particularly within this often-overlooked group of older patients to increase early detection of CRC.