Breast Cancer Screening for Women in Their 40s Improves Survival
Are you confused about when to start getting mammograms? If you are, you’re not alone. There are many different recommendations and guidelines. A new study offers some critical information: Breast cancer screening programs that included women ages 40 to 49 led to better survival for those who were diagnosed with the disease.
The study was published online on Aug. 4, 2023, by the Journal of Clinical Oncology. Read “Impact of Breast Cancer Screening on 10-Year Net Survival in Canadian Women Age 40-49 Years.”
So many breast cancer screening recommendations, so much confusion
From 2000 to 2015, a number of large studies ignited debate over when people should begin having mammograms.
Public health experts agree that breast cancer screening saves lives, but question the value of screening mammograms. These experts say that for each breast cancer death screening mammograms prevent, three to four women are overdiagnosed.
Overdiagnosis means that a screening mammogram finds:
a suspicious area that would have been eventually diagnosed as cancer by other means without affecting the prognosis
a suspicious area that never would have been diagnosed as cancer if it had been found or treated
False-positive results from screening mammograms also have helped fuel the debate about the value of breast cancer screening and when it should start. When a mammogram shows an abnormal area that looks like cancer but turns out to be normal, it’s called a false positive. Ultimately the news is good: no breast cancer. But the suspicious area usually requires follow-up with more than one doctor, extra tests, and extra procedures — including a possible biopsy. There are psychological, physical, and economic costs that come with a false positive.
Because of the continued debate, a number of organizations revised their breast cancer screening recommendations for women at average risk of breast cancer. Some organizations recommend starting screening mammograms at age 50, and others recommend starting at age 40. At the same time, some organizations recommend having a mammogram each year, and others recommend having a mammogram every other year. As a result, many women aren’t sure when they should start having screening mammograms or how often.
To clarify when people should start getting mammograms, the National Comprehensive Cancer Network (NCCN) released guidelines for breast cancer screening and diagnosis in 2022 that say everyone who has breasts age 40 and older at average risk of breast cancer should have an annual mammogram.
About the study
The researchers used information from the Canadian Cancer Registry to look at death information for two groups of women diagnosed with breast cancer between 2002 and 2007: women ages 40 to 49 and women ages 50 to 59.
Overall, 50,921 cases of breast cancer were diagnosed between 2002 and 2007:
21,103 cases were women ages 40 to 49
29,818 cases were in women ages 50 to 59
Of the 21,103 breast cancer cases in women ages 40 to 49:
5,680 were in areas with screening programs for women in their 40s
15,408 were in areas with no screening programs for women in their 40s
15 cases were in Nunavut and the researchers weren’t sure if the screening program included women in their 40s
The researchers estimated 10-year survival rates for women ages 40 to 49 diagnosed with breast cancer based on the screening program where they lived.
Survival rates were:
84.8% for women in areas with screening programs for women in their 40s
82.9% for women in areas with no screening programs for women in their 40s
This 1.9 percentage point difference was statistically significant, which means it was likely due to the difference in screening and not just because of chance.
Ten-year survival rates for women ages 50 to 59 were 83%.
Breast cancer was the main cause of death in women ages 40 to 49 who were diagnosed with breast cancer, accounting for 90.7% of deaths.
The older a woman was when diagnosed, the less likely breast cancer was to be the cause of death. Breast cancer accounted for:
80.9% of deaths for women diagnosed in their 50s
61.5% for women diagnosed in their 60s
48.3% for women diagnosed from age 70 to 74
The researchers noted that other factors besides screening could contribute to the difference in survival, including:
access to care
available treatments; the information the researchers analyzed was collected before Herceptin (chemical name: trastuzumab) was available to treat HER2-positive breast cancer and aromatase inhibitors were available to treatment hormone receptor-positive breast cancer
the ethnicity of the women diagnosed
The researchers also pointed out that only about 31% to 53% of women in their 40s who lived in areas with screening programs for that age group actually had a mammogram, far below the target rate of 70%.
“Despite suboptimal screening participation and a cohort diagnosed before two major treatment advances, this study suggests that [breast cancer] screening programs for women age 40 to 49 years may translate into a significant survival benefit,” the researchers concluded. “These results may inform screening guidelines for women age 40 to 49 years.”
What this means for you
Breastcancer.org believes your best chance for early detection — whether you’re in your 40s, 50s, 60s, 70s, or 80s — requires coordination of the current screening tools:
high-quality mammography
clinical breast exams
breast self-exams
If you’re not using all three tools starting at age 40, it’s a missed opportunity for early detection.
The reality is that everyone with breast tissue is at risk for breast cancer, and this risk tends to increase over time. It’s important to understand your health information related to breast cancer risk and to keep your doctor updated throughout your life. Here are some points to discuss with your doctor:
family history of breast or other related cancers (ovarian, melanoma)
any test results for gene mutations linked to a higher-than-average breast cancer risk
results of past breast biopsies, even if they were benign
personal history of radiation treatment to the face, chest, or both before age 30
breast density
weight
level of physical activity
any use of post-menopausal combined hormone replacement therapy (HRT)
alcohol consumption, if you regularly drink more than three alcoholic beverages a week
the amount of processed food and trans fats you eat
your smoking history
whether or not you have carried a pregnancy to term or have breastfed
If you have a higher-than-average risk of developing breast cancer, you should talk to your doctor about starting annual mammograms at a younger age and consider other screening tools (such as MRI or ultrasound) to increase your chances of early detection.
— Last updated on October 18, 2023 at 6:41 PM