Breast cancer is possible at any age. As far as the chances of getting breast cancer at 20 . . when it happens to you . . what does 'rare' mean? My son was diagnosed at 17 years old with a rare abdominal sarcoma. One week he was playing basketball the next week he was in the hospital with stage IV cancer. His type of cancer has only about 200 cases diagnosed in the world at any given time. So . .here is what I think . . the medical profession is doing a poor job in alerting teenagers and young adults that they too can have cancer. Teens and young adults are so healthy that they can actually go for months ignoring symptoms of cancer . . and still function like healthy individuals. Cancer is asymptomatic for most young people until it is very advanced. If your 19 year old is concerned for any reason whatsoever that she might have cancer . . . LISTEN TO HER!!!! I wish I had listened to my 17 year old when he told me he felt something was wrong . . . but he looked and acted so healthy we did not pay that much attention. So, yes, a 19 year old can get breast cancer. She should be checked. You can look for more information at sites like Young Survival Coalition - what you read there may save your daughters life: http://www.youngsurvival.org/young-women-and-bc/ "Young women CAN and DO get breast cancer. While breast cancer in young women accounts for a small percentage of all breast cancer cases, the impact of this disease is widespread: There are more than 250,000 women 40 and under in the U.S. living with breast cancer, and over 11,100 young women will be diagnosed in the next year. But, despite the fact that breast cancer is the leading cause of cancer death in women ages 15 to 54: Many young women and their doctors are unaware that they are at risk for breast cancer. There is no effective breast cancer screening tool for women 40 and under. Young women are often diagnosed at a later stage than their older counterparts." Children can also have breast cancer, although it too is very rare. Juvenile Secretory Carcinoma is a rare form of breast cancer in children. Cystosarcoma Phylloides is also a rare tumor of the breast that can occur in children. There are also secondary cancers such as lymphoma which can spred to the breast in children. Good luck to you and your daughter as you sort this issue out. I'm a bit on edge about this issue today because a young 23 year old girl died yesterday . . she had secondary breast cancer as well as the same type of sarcoma that my son has. Take your daughters concerns seriously.