The prevalence and clinical characteristics of cancer among anemia patients treated at an outpatient clinic.

Background: Anemia is the most common hematologic condition encountered in outpatient clinics. It is often overlooked because it is common among patients; however, anemia is one of the leading indicators of cancer. This study examined the prevalence and characteristics of cancer among anemia patients who visited an outpatient clinic.

Methods: The data were collected by reviewing the records of an outpatient clinic from January 2007 to December 2011.

Results: In total, 502 patients (52 males, 450 females) were diagnosed with anemia. Cancer prevalence among anemia patients was 5.57% (25.0%, men; 3.3%, women); further, the most frequently diagnosed cancer was colorectal cancer (22.5%), followed by advanced gastric cancer (16.1%), breast cancer (9.6%), myelodysplastic syndrome (9.6%), cervical cancer (6.4%), renal-cell carcinoma (6.4%), and thyroid cancer (6.4%). The prevalence of cancer was 4.1% in those aged 40-49 years, 4.2% in the subjects in their fifties, 8.0% in those in their sixties, 21.6% in those in their seventies, and 55.6% in those aged over 80 years. The cancer prevalence among iron deficiency anemia (IDA) patients was 6.18% (28.8%, men; 3.5%, women). The cancer prevalence in postmenopausal and premenopausal female IDA patients was 16.0% and 1.6%, respectively.

Conclusion: Among anemia patients, male patients aged over 40 years and female patients aged over 60 years, along with postmenopausal female patients, were more likely to be diagnosed with cancer. Consequently, male IDA patients, and female patients aged over 60 years must be carefully evaluated for the possibility of malignancy.