See a doctor if you notice changes in your breast that could signal cancer - even if you've recently had a normal mammogram. Symptoms include lumps and changes in breast skin, shape, or size. All women should conduct monthly breast self-exams and see a health care provider annually for a manual breast exam. The earlier you catch breast cancer, the more likely it will be cured.
However, in its earliest stages, breast cancer shows no symptoms. Women over age 50 should get regular mammograms, which can catch breast cancer before symptoms appear.