Each month, a woman's breasts go through temporary changes associated with menstruation and a lump may form. While the vast majority of these growths are not breast cancer, any lump should be examined immediately.
Breast lumps are most common in the lobules -- small sacs that produce milk -- or the ducts that carry milk to the nipple. But they occasionally start in other tissue. The two main categories of breast cancer are lobular and ductal carcinomas.
These four women lead very different lives, but they all have one thing in common: They developed breast cancer at a young age. They discovered community within the Young Survival Coalition, a national organization dedicated to providing support to young women with breast cancer -- and raising awareness of the disease in women under 40.
Breast cancer usually begins with the formation of a small, confined tumor. Some tumors are benign, meaning they do not invade other tissue; others are malignant, or cancerous. Malignant tumors have the potential to metastasize, or spread. Once such a tumor grows to a certain size, it is more likely to shed cells that spread to other parts of the body through the bloodstream and lymphatic system. Different types of breast cancer grow and spread at different rates; some take years to spread beyond the breast, while others move quickly.
Men can get breast cancer, too, but they account for less than one-half of one percent of all cases. Among women, breast cancer is the most common cancer and the second leading cause of cancer deaths -- behind lung cancer.
If eight women were to live to be at least 90, one of them would be expected to develop the disease at some point during her life. Two-thirds of women with breast cancer are over 50, and most of the rest are between 39 and 49.
Fortunately, breast cancer is very treatable if detected early. Localized tumors can usually be treated successfully before the cancer spreads; and in nine in 10 cases, the woman will live at least another five years.
Once the cancer begins to spread, getting rid of it completely is more difficult, although treatment can often control the disease for years. Improved screening procedures and treatment options mean that at least seven out of 10 women with breast cancer will survive more than five years after initial diagnosis, and half will survive more than 10 years.