The guidelines from different organizations vary. If you are of average risk for breast cancer, you should start undergoing a yearly mammogram at age 40. This recommendation is in accordance with the American Cancer Society's recommendations. When should screening begin if there is a strong family history of breast cancer? If it is determined that you are of high risk of developing breast cancer based on family history or other factors you should start screening with mammography and and/or breast MRI possibly at age 30. However, many factors contribute to risk and each case must be considered individually.
Breast MRI is currently not used for screening average risk patients. An MRI might be considered if you have been determined to have a very high risk (20-25% risk) of developing breast cancer in your lifetime, you can feel a lump but it is not seen on mammogram, if you had a previous breast cancer that was not seen on mammogram, or you have a strong family history of breast and ovarian cancer. These are just some of the reasons and decision-making varies on a case by case basis.
There is no evidence that breast exams prevent death from breast cancer. However, I advocate breast awareness and monitoring yourself for changes in your breasts as some women do identify breast cancers on self-exam.
It is important to provide an accurate family and personal history of breast or other cancers to your doctor. Also, you should discuss any benign breast problems you have had in the past that have required biopsy. You should ask your doctor what your breast cancer risk factors are, when you should begin screening, and if genetic testing would be appropriate.
There are several breast cancer risk factors. Some of the risk factors you can control and some you cannot. Even if you possess one or more of the risk factors, it does not mean that you will develop breast cancer. Some of the risk factors include age, female gender, genetic predisposition, personal or family history of breast cancer, alcohol consumption, and obesity.
There is no strong data to suggest that any one diet is better at preventing breast cancer. However, breast cancer is less common in countries where they eat lower fat diets. Eating a healthy diet with plenty of fruits and vegetables and watching your calories is the best option since obesity is a known risk factor for breast cancer.
This is based on your personal and family history and is something you should discuss with your doctor. There are also genetic counselors that can assist in determining your risk and discussing testing and its implications.