Breast Cancer Still a Leading Cause of Death – About 231,840 new cases of invasive breast cancer are estimated to occur in women this year and about 40,950 deaths from breast cancer will result, according to the American Cancer Society (ACS). Breast cancer remains the most common cancer among women in the U.S. – other than skin cancer – and breast cancer is the second leading cause of cancer death in women, after lung cancer. According to the U.S. Preventive Services Task Force, a federal research agency (USPSTF), the median age at diagnosis is 61 years and the median age at death is 68 years.