With a family history of breast malignancy, when's the best time for me to get my first mammogram?

Earlier: You should start 10 years before the youngest family member age at diagnosis. Example: mother had breast cancer at 40, you should start at 30.

10yrs earlier...: ...Than the age of diagnosis of any close relative with breast cancer, or at age 40 (whichever age is lower). As an aside, you may want to clarify with a breast doctor just how high your risk is for breast cancer. Most cases of breast ca are environmental, not hereditary. People have a tendency to assume more risk than may actually be present.

If you are 42,: you should start annual screening now.