Breast Cancer: From Molecular Subtypes to Metastasis

Abstract

Breast cancer is the most common cancer among women and is the leading cause of female mortality worldwide. According to the American Cancer Society, 13% of women (1 in 8 women) will have been diagnosed with breast cancer at least once in their lifetime. Although breast cancer is more common in women, men are also susceptible to breast cancer, but to a much lesser extent. Only 0.12% of men (one in 833 men) are diagnosed with breast cancer. Breast cancer is caused by the interplay between genes and specific environmental factors. The classification of breast cancer into different molecular subtypes that are different from each other affects the choice of the type of treatments. A number of recent studies have shown a significant relationship between breast cancer molecular subtype and metastatic status. The metastasis is a process of biological actions that must be completed by cancer cells to exit the primary tumor and develop a new tumor at a distant site. Certain breast cancer molecular subtypes are more likely to cause metastases in certain organs of the body than others. Primary and secondary breast cancer of the triple-negative molecular subtype is often the worst, followed by the HER+ molecular subtype.