Breast cancer starts when healthy breast cells change and grow out of control. Cells that grow out of control form a mass of cells called a tumor. Tumors can be benign or malignant. It is malignant when it grows and spreads to other parts of the body, and it is benign when it grows and does not spread. Although breast cancer most often spreads to nearby lymph nodes, breast cancer is still considered a localized disease. It can spread throughout the body through blood vessels or lymph nodes to places such as the bones, lungs, liver, and brain. This is called metastatic or stage four breast cancer, although involvement of only nearby lymph nodes is usually not stage four breast cancer.
Breast cancer statistics
In 2020, there were 2,261,419 new cases of breast cancer among women worldwide. In 2023, an estimated 297,790 women in the United States will be diagnosed with invasive breast cancer, and 55,720 women will be diagnosed with noninvasive breast cancer. Since the mid-2000s, invasive breast cancer in women has increased by about half a percent each year. Currently, 4 million women in the United States have breast cancer. Breast cancer is the fifth leading cause of death among women worldwide. In 2020, worldwide, 684,996 women died of breast cancer.
Breast cancer is usually diagnosed in middle-aged and older women. The average age of diagnosis is 63 years. Although it is not common, some women are diagnosed with the disease before the age of 45.
Breast cancer survival rate
There are different types of statistics that help doctors estimate the chances of being cured of breast cancer, called survival statistics. It is important to note that survival rates for people with breast cancer are only approximate. In the US, the five-year relative survival rate for women with non-metastatic invasive breast cancer is 91%, and the ten-year relative survival rate is 85%. Breast cancer survival rates vary and depend on several factors, including the stage of the cancer, the person’s age, and general health. If invasive breast cancer is located only in the breast, the relative five-year survival rate for women with this disease is 99%. About 6% of women have cancer that has spread outside the breast and lymph nodes.