Here are some quick facts about breast skin cancer in the U.S. Breast cancer is the most common cancer among American women. Each year in the United States, more than 245,000 women get breast cancer and more than 40,000 women die from the disease. Most breast cancers are found in women who are 50 years old or older, but breast cancer also affects younger women. About 10% of all new cases of breast cancer in the United States are found in women younger than 45 years of age.