Short answers, pulled from the story.
The most common symptom of breast cancer is a new lump in the breast, though most lumps turn out not to be cancerous. Other signs include skin thickening (called peau d'orange), dimpling, redness, nipple inversion, unusual discharge, and swollen lymph nodes under the arm or along the collar bone. Most people with breast cancer have no symptoms at all at the time of diagnosis, with the tumor detected only by screening.
About five to ten percent of breast cancer cases result from inherited genetic predispositions, including BRCA mutations. Women with pathogenic variants in BRCA1 or BRCA2 face around a 70% lifetime chance of developing breast cancer, as well as an approximately 33% chance of developing ovarian cancer.
Mammography can detect around 90% of breast tumors in the least dense (fatty) breasts, but only about 60% in the most dense breasts. Overall, screening mammograms miss about 1 in 8 breast cancers. Regular screening mammography reduces breast cancer deaths by at least 20%.
Overall, 92% of women diagnosed with breast cancer in the United States survive at least five years from diagnosis. Those whose tumors are completely confined to the breast have a 100% five-year survival rate. Those with tumors that have metastasized to distant sites have a 33% five-year survival rate.
Drinking alcohol increases breast cancer risk even among very light drinkers, including women who drink less than half of one alcoholic drink per day. Globally, about one in ten breast cancer cases is attributed to alcohol consumption. Alcohol use is among the most common modifiable risk factors for the disease.
The oldest known evidence of breast cancer dates back 4,200 years to ancient Egypt, to the Sixth Dynasty. The study of a woman's remains from the necropolis of Qubbet el-Hawa showed the typical destructive damage of metastatic spread. The Edwin Smith Papyrus describes eight cases of breast tumors and states, "There is no treatment."