According to the American Cancer Society (www.cancer.org)

The earlier breast cancer is found, the better the chances that treatment will work. The goal is to find cancers before they start to cause symptoms. The size of a breast cancer and how far it has spread are the most important factors in predicting the outlook for the patient. Following the guidelines given here improves the chances that breast cancer can be found at an early stage and treated with success.

Women in their 20s and 30s:

• Have a medical provider check breasts for lumps (clinic breast exam or CBE) at your yearly doctor’s visit. 

• Breast self exam is an option for women starting in their 20s.  Know how your breasts normally feel and report any changes to their health care provider. 

Women age 40 and over:

• Clinical breast exam and mammograms are recommended every year.

Women at high risk: Women with a higher risk of breast cancer should talk with their doctor about the best screening plan for them.