Today, I want to chat about the truth about breast cancer screening in your 40s.

Start screening mammograms at 50.

No, 40.

How about 45?

Do mammograms even save lives?

I am a radiation oncologist with a special interest in breast cancer, and I want to share what you should know about screening.

Breast Cancer Incidence Generally Rises With Age

Mammogram benefits vary by age.

For example, women ages 50 to 69 generally benefit most from screening mammograms.

One reason is that breast cancer incidence generally increases with age:

Mammogram Accuracy Varies By Age

Breast density affects mammogram accuracy.

What I mean is this:

Screening mammograms miss about one in eight breast cancers. Women with dense breasts are more likely to get false-negative results.

Age and weight influence breast density: Dense breasts are more common in young women.

Lean women are also more likely to have dense breasts: Roughly 50 to 60 percent of women with a healthy weight have dense breasts, compared to 20 to 30 percent of obese women.

Dense breast tissue can make abnormal findings harder to see on a mammogram.

Fortunately, radiologists can find most breast cancers on a mammogram, even in women who have dense breast tissue.

Do Mammograms Save Lives?

A new study presented at the Family Medicine Forum 2024 showed this result for Canadian women not at high risk for breast cancer:

When they participated in organized mammography screening programs, individuals aged 40 to 49 had a significantly higher 10-year survival rate after diagnosis.

Study Results in Detail

The 10-year survival in jurisdictions that offered screening was 84.8 percent.

The survival odds were 82.9 percent, or 1.9 percent lower in jurisdictions not offering screening.

The survival advantage (2.6 percent) for screening jurisdictions was significant for women aged 45 to 49.

There was no significant survival advantage for those aged 40 to 44 years.

This finding suggests that the benefits of mammography for women in their early 40s may be less clear-cut.

Study Details: Breast Cancer Screening in Your 40s

Researchers analyzed the impact of breast cancer screening programs on survival rates in Canadian women.

They analyzed data from the Canadian Cancer Registry, comparing 10-year survival rates of women aged 40 to 49 diagnosed with breast cancer between 2002 and 2007 in regions with and without organized screening programs.

They also included women aged 50 to 59 in their analysis.

Screening Recommendations

According to the U.S. Preventive Services Task Force (USPSTF), all women should get screened for breast cancer with a mammogram every two years, starting at age 40 and continuing through age 74.

Key Points

• Age range: 40 to 74 years old
• Frequency: Every 2 years
• Applies to: Cisgender women and all other people assigned female at birth
• Considerations for high-risk individuals: Women with a family history of breast cancer or dense breasts should discuss additional screening options with their doctor.
• Insufficient evidence for older women: The USPSTF states that there is not enough evidence to determine the benefits and harms of screening mammography for women over 75.

Screening Recommendations Can Vary

Please keep in mind that different organizations sometimes have different recommendations for health screenings.

Please reach out to your primary care provider for personal guidance.

Have you gotten your appropriate cancer screening?

Thank you for reading “Breast Cancer Screening in Your 40s.”