Advice varies on when women should start getting screened for breast cancer and how often. The American Cancer Society revised its guidelines Tuesday, bringing them more in line with those of the U.S. Preventive Services Task Force, an influential government-appointed panel.

A comparison of the two groups:

American Cancer Society

-Mammograms: Start yearly scans at age 45, shift to every other year at age 55 and for as long as women are in good health and have a life expectancy of at least 10 years. Mammograms can still be an option for women who prefer to start in their early 40s who are informed of potential benefits and risks for false alarms.

-Physical breast exams by doctors: Not recommended.

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U.S. Preventive Services Task Force:

-Mammograms: Scans every other year starting at age 50, until age 74. More research is needed on potential benefits in women 75 and older. In draft of upcoming update: mammograms can still be an option for women who prefer to start in their 40s who are informed of potential benefits and risks.

-Physical breast exams by doctors: No recommendation for or against, citing lack of evidence on benefits or harms.