Some Women May Benefit From Mammography Screening Beginning at Age 30

Cindy S. Lee, MD

Women between the ages of 30 and 39 who have at least 1 of 3 risk factors may benefit from starting their annual mammography screening at age 30, according to results from a large-scale study that was presented at the 2018 Radiological Society of North America Annual Meeting.¹

The 3 risk factors include a breast density of heterogeneously or extremely dense, a personal history of breast cancer, or a family history of breast cancer.

Currently, the American Cancer Society recommends that all women who are at average risk for breast cancer begin yearly breast cancer screening at age 45, with the option to receive an annual mammogram once they are 40 years of age. However, recommendations for younger women between the ages of 30 and 39 are unclear.

"Women under 40 have not been the focus of our attention when it comes to breast cancer screening,” Cindy S. Lee, MD, an assistant professor of radiology at NYU Langone Health, said in a press release.² “Everyone is talking about the 40 to 49 range, and not the 30 to 39 age range."

This population is particularly challenging to evaluate because most women in this age group do not receive mammograms, Lee added. However, there are younger women who may be at increased risk for breast cancer who could potentially benefit from early or supplemental screening.

In an effort to provide sufficient evidence to support that hypothesis, Lee and colleagues compared performance metrics of screening younger women between the ages of 30 and 39 and had the 3 risk factors for breast cancer with metrics of screening older women between the ages of 40 and 49 without those risk factors. The information was collected from the National Mammography Database.

For the study, the investigative team evaluated data from 5,772,730 screening mammograms that were performed in a total of 2,647,215 women in 150 facilities throughout 31 states from January 2008 to December 2015. Patients were stratified by 5-year age intervals and specific risk factors for breast cancer.

Current breast risk prediction models incorporate different risk factors than those used in the study, according to Lee, and because these factors are often weighed differently, they can produce different results for the same patient—resulting in confusion and uncertainty for doctors and patients. To avoid this complexity, investigators defined increased risk for breast cancer as any woman who had a breast density of heterogeneously or extremely dense (C or D), a personal history of breast cancer, or a history of breast cancer in any first-degree relative, regardless of age.

The team calculated performance metrics for screening mammography for each age and risk group, with a specific focus on recall rate, cancer detection rate, and positive predictive values for biopsy recommended (PPV2) and biopsy performed (PPV3).

Overall, results showed that the mean recall rate was 9.8% (95% CI, 9.8-9.8) and the cancer detection rate was 3.7 per 1000 (95% CI, 3.65-3.75), while PPV2 was 20.1% (95% CI, 19.9-20.4) and PPV3 was 28.2% (27.0-28.5).

Women between the ages of 30 and 34 had cancer detection rates, recall rates, and PPVs that were comparable to women between the ages of 35 and 39. In addition, the presence of the 3 evaluated risk factors were found to be associated with substantially higher cancer detection rates.

In addition, incidence mammography screening of women between the ages of 30 and 39 with the 3 evaluated risk factors had cancer detection rates and recall rates similar to those between the ages of 40 and 44 without known risk factors.

Therefore, the investigators concluded that younger women between the ages of 30 and 39 with any of the 3 evaluated risk factors could potentially benefit from beginning annual mammography screening earlier, at age 30, rather than the currently recommended age of 40.

References

1. Lee C. Risk-based screening mammography for women age <40: Outcomes from the National Mammography Database. In: Proceedings from the Radiological Society of North America annual meeting; Nov. 25-30, 2018; Chicago, Illinois. https://bit.ly/2FLtU9f . Accessed November 28, 2018.
2. New Study Supports Mammography Screening at 30 for Some Women. Radiological Society of North America. Published November 28, 2018. https://bit.ly/2ABi8IK. Accessed November 28, 2018.