Interleukins in the Development and Progression of Breast Cancer

Breast cancer is one of the most frequently diagnosed cancers globally, with the highest mortality in women. Despite remarkable advances in treatment approaches, breast cancer still holds the top position in cancer-associated deaths in women. Over the last few decades, researchers have been trying to reveal the exact etiology of this malignancy, for example, revealing molecular mechanisms behind this. Inflammation is a critical factor leading to breast cancer development and progression. Many inflammatory cytokines or biomarkers, especially interleukins (ILs), are extensively studied due to their prominent role in inflammation leading to breast tumors’ initiation, promotion, and progression. Exposure of breast epithelial cells to these cytokines promotes excessive proliferation, enhanced survival, malignant transformation, and cancer development. Previous studies reported that some ILs are associated with acute inflammatory processes, including IL-8 and IL-12, whereas some with chronic inflammatory responses include IL-2, IL-3, IL-6, IL-10, IL-12, and others. Moreover, chronic inflammation leads to different signaling mechanisms and transcription factors and alters both the patient’s innate and adaptive immune responses. This chapter will discuss the major ILs and their role in the development and progression of breast cancer. Besides, the authors will try to provide an insight into the mechanisms in both the tumor cell and tumor microenvironment that result in breast cancer progression. They anticipate the data described in this chapter will play an important role in proposing newer therapeutic approaches to treat breast cancer.