OBJECTIVES: In 2009, the United States Preventive Services Task Force changed the recommended minimum age for mammograms from 40 to 50. The study examines whether this change affects breast cancer survival for women in the United States.

METHODS: This study selects 784136 patients from the Surveillance Epidemiology and End Results Program from 2000 to 2018, with setting women aged between 40 and 49 as the treatment group and women aged 50 and over as the control group. The treatment time is 2009 because before 2009 both groups were recommended for mammograms, but after 2009 the treatment group is no longer recommended. A Difference-in-difference model is adopted for the effect of the changed age recommendation on breast cancer mortality between the treatment and control groups before and after 2009. The analysis also specifies subtypes of breast cancer including breast cancer of infiltrating duct, adenocarcinoma, lobular, phyllodes, medullary, Paget, ductal, metaplastic, inflammatory and others.

RESULTS: The recommendation of postponed age for mammograms increases the survival months of breast cancer patients by 10.06. Also this change in recommended age increases the survival months of breast cancer of infiltrating duct (9.44), adenocarcinoma (13.87), lobular (10.17), medullary (12.88), Paget (10.13), metaplastic (12.86) and others (21.38). However, this change does not affect the survival of breast cancer of phyllodes, ductal and inflammatory.

CONCLUSIONS: The updated recommendation of mammograms for older ages promotes the survival of breast cancer and most of its subtypes. The increased survival can result from older patients getting diagnosed and starting treatments earlier after this updated recommendation improves their availability of mammograms. In addition, this study found that this updated recommendation has no significant contribution to the survival of phyllodes, ductal, and inflammatory breast cancers, indicating a limited effect of the updated age recommendation.