• Breast Cancer following Diabetes Mellitus: truth or not?
  • AmirAli Moodi Ghalibaf,1,* Mina AkbariRad,2 Nazanin Forghani,3
    1. Student Research Committee, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
    2. Assistant professor of Internal Medicine, Department of Internal Medicine, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
    3. Student Research Committee, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.


  • Introduction: Today, breast cancer (BC) becomes one of the most prevalent malignancies among women all over the world which causes millions of deaths every year. Unfortunately, too many exogenous and endogenous factors can increase the risk of BC incidence. In this term, some studies and evidence have been indicated that the human immune system status and hormonal changes of the body are strong potential factors in BC development. On the other hand, diabetes mellitus (DM) is known as the most common metabolic disorder worldwide that can be caused by autoimmune and hormonal dysfunctions in one's body. These joint processes in both BC and DM can potentially interact with each other and lead to one another disorder. Therefore, we are looking for the answer to the question of whether DM can lead to BC, or not?
  • Methods: A comprehensive search was done through electronic databases including PubMed, Scopus, Embase, and Web of Science with the keywords “Breast Cancer”, “Diabetes Mellitus” and other related MeSH terms up to July 2021. Original studies, review studies, and the references of the review studies were included. Finally, the related studies which investigated the possible relationship between BC and DM were reviewed.
  • Results: According to the reviewed of population-based epidemiological studies, it can be stated that diabetic Asian-American women have a significantly higher risk of BC; however, a wide range of the BC incidence between 15%-20% was reported in DM patients. On the other hand, some molecular mechanisms were potentially considered for the association between BC and DM, including activation of the insulin-like growth factors (IGFs) pathway, activation of the insulin pathway, chronic hyperglycemia leading to the Warburg effect, inflammatory cytokines, and the regulation of endogenous sex hormones. In detail, a decrease in estrogen plasma levels following insulin resistance can increase the risk of BC development. Moreover, studies determined that diabetic BC patients have more morbidities and mortalities, severe outcomes, need altered regimens for breast cancer treatment, and experience increased toxicity from cancer chemotherapy. Finally, the studies on the BC staging indicated that DM has highly associated with stages III, IV, II, and I of BC, respectively.
  • Conclusion: Based on the mentioned finding, Breast Cancer can be significantly affected by Diabetes Mellitus in terms of incidence, outcomes, and management; however, more studies are needed to find out the exact molecular processes and other aspects of this association.
  • Keywords: Breast Cancer, Diabetes Mellitus, Insulin Resistance