Patients concerned about anemia may anticipate that certain cancers are capable of causing the condition, whether that’s due to the cancer attacking the blood cells or on account of the effects of chemotherapy.¹ However, they may not be sure whether the development of anemia puts them at an increased risk for cancer.
Anemia causes a reduced red blood cell count in patients, making it more difficult for the body to perform its normal functions. If anemia is a potential predictor or risk factor for cancer, patients should know so they can better prepare for more timely cancer screenings. For patients with cancer, a severe enough case of anemia could result in treatment being delayed. What do we know about potential links to cancer risk among those with anemia? Are there specific types of cancer involved? And what is needed in future research?
Does Anemia Increase Overall Cancer Risk?
Multiple studies in recent years have suggested there is a link between anemia and an increase in cancer risk and incidence. A 2022 study published in BMC Cancer, for example, observed electronic data from health care registries in Denmark that included people with no history of cancer and new-onset anemia to find a potential link in cancer incidence.² In examining the members of the population cohort who were diagnosed with cancer during a 12-month follow up period, the investigators found a significantly greater incidence of cancer in those with new-onset anemia than in those without. This led the researchers to conclude that anemia is associated with an elevated risk of cancer.
Other studies have arrived at similar conclusions. In 2015, a study in PLoS One evaluated patients newly diagnosed with iron deficiency anemia from the Taiwan National Health Insurance Research Database and found that they had a significantly higher incidence of cancer (even when excluding patients diagnosed with cancer within the first five years of their anemia diagnosis).³ A 2021 study in Cancer Epidemiology, Biomarkers & Prevention examined similar data from South Korea, with anemia defined by the participants’ serum hemoglobin levels — in that study, too, anemia was associated with an increased risk of overall cancer.⁴
Risk by Types of Anemia and Cancer
These studies also made note of how the types of anemia and cancer interact. The researchers of the PLoS One study focused on patients with iron deficiency anemia in particular, and found that beyond overall cancer risk, patients had specific elevated risks for pancreatic, liver, bladder, and kidney cancers.³
Other cancers have been linked to a history of anemia as well: the study in Cancer Epidemiology, Biomarkers & Prevention showed anemia brings an increased risk of thyroid, lung, esophageal, and gastric cancers, as well as lymphoma, leukemia, and neoplasms in the breasts and genital organs.⁴ In terms of types of anemia, the investigators of the study in BMC Cancer saw a particularly high incidence of cancer in women with anemia of inflammation and men with combined inflammatory iron deficiency anemia.² Men and women with combined inflammatory iron deficiency anemia had an increased incidence of gastrointestinal cancer in particular, as did men with iron deficiency anemia.
What Future Research is Needed?
These studies all concluded that there is an increased risk of cancer in patients with anemia; they also conclude that more research is needed on the subject to provide optimal care for patients, to determine the mechanism that causes this association, and to identify long-term cancer risk in patients.
1. Cirino E. Anemia and cancer: what do you need to know? Healthline. https://www.healthline.com/health/cancer/anemia-cancer. Updated June 22, 2022. Accessed January 10, 2023.
2. Boennelykke A, Jensen H, Østgård LSG, Falborg AZ, Hansen AT, Christensen KS, Vedsted P. Cancer risk in persons with new-onset anaemia: a population-based cohort study in Denmark. BMC Cancer. 2022 Jul 21;22(1):805. doi: 10.1186/s12885-022-09912-7. PMID: 35864463; PMCID: PMC9306185.
3. Hung N, Shen CC, Hu YW, Hu LY, Yeh CM, Teng CJ, Kuan AS, Chen SC, Chen TJ, Liu CJ. Risk of cancer in patients with iron deficiency anemia: a nationwide population-based study. PLoS One. 2015 Mar 17;10(3):e0119647. doi: 10.1371/journal.pone.0119647. Erratum in: PLoS One. 2015;10(4):e0125951. PMID: 25781632; PMCID: PMC4363660.
4. Oh TK, Song I-A. Anemia may increase the overall risk of cancer: findings from a cohort study with a 12-year follow-up period in South Korea. Cancer Epidemiol Biomarkers Prev. 2021;30(7):1440-1448. doi:10.1158/1055-9965.epi-20-1840