What to know
From 2001 to 2021, a total of 4,652,885 new cases of female breast cancer were reported in the United States. Of these, 260,379 (5.6%) were distant stage (metastatic) at diagnosis. The incidence of metastatic female breast cancer increased from 2001 (5.8 per 100,000 females) to 2021 (7.9 per 100,000).
Introduction
Breast cancer is the second most common cancer among women in the United States (non-melanoma skin cancer is the most common). It is the second leading cause of cancer death among women, after lung cancer.
Distant metastatic breast cancer—or cancer that has spread from the breast to distant parts of the body—has the lowest cancer survival rate. For this analysis, all cases collected are primary tumors and therefore do not reflect recurrent cancer diagnoses or tumors that progressed from local or regional stages to metastatic stage.
The overall incidence of female breast cancer (at any stage) increased an average of 0.5% per year from 2001 to 2021. Trends for incidence increased the most for cases diagnosed at metastatic stage (1.6%) than at other stages. The incidence rate of metastatic female breast cancer was 5.8 per 100,000 in 2001 and increased to 7.9 per 100,000 in 2021 (Figure 1).
Trends in metastatic female breast cancer incidence by race and ethnicity
From 2001 to 2021, metastatic female breast cancer incidence was higher among non-Hispanic Black women than among women in all other U.S. racial and ethnic groups (Figure 2).
It also increased for women in all racial and ethnic groups during this period. Incidence increased more among non-Hispanic American Indian and Alaska Native women (3.3%) and non-Hispanic Asian and Pacific Islander women (2.9%) than among non-Hispanic Black women (1.5%), Hispanic or Latino women (1.7%), and non-Hispanic White women (1.5%).
Incidence rates of metastatic female breast cancer stage by age
From 2001 to 2021, metastatic female breast cancer incidence increased with age and was highest among women aged 75 years and older (25.5 cases per 100,000) and lowest among women younger than 40 years (<1 case per 100,000) (Table 1).
Table 1. Incidence ratea of female breast cancer by age and stage at diagnosis, United States, 2001–2021
| Age (years) | Stage: Localized | Stage: Regional | Stage: Distant (Metastatic) | Stage: Unknown |
|---|---|---|---|---|
| Younger than 40 | 6.4 | 6.0 | 0.9 | 0.4 |
| 40 to 44 | 68.9 | 47.0 | 5.9 | 3.2 |
| 45 to 49 | 111.1 | 66.4 | 9.0 | 4.5 |
| 50 to 54 | 137.3 | 74.2 | 12.2 | 5.6 |
| 55 to 59 | 169.6 | 81.2 | 15.8 | 6.6 |
| 60 to 64 | 222.0 | 91.1 | 19.4 | 8.3 |
| 65 to 69 | 285.2 | 99.7 | 21.8 | 10.2 |
| 70 to 74 | 314.7 | 99.5 | 23.4 | 11.8 |
| 75 or older | 272.6 | 92.0 | 25.5 | 18.7 |
Screening recommendation
The U.S. Preventive Services Task Force updated its breast cancer screening recommendations in April 2024. Women aged 40 to 74 are now recommended to get screening mammography every other year. Screening rates differ among different groups of women, which can lead to disparities in time to diagnosis and treatment. Research is needed to understand these disparities.
Conclusion
Rates of female breast cancer diagnosed at the metastatic stage have been increasing over the past two decades. People diagnosed with metastatic breast cancer typically do not live as long as those diagnosed with cancer at an earlier stage. Therefore, it is important to identify cancer before it becomes metastatic. Screening and timely receipt of follow-up tests and treatment, as needed, can lower the risk of dying from breast cancer.
Data source
Data in this brief come from U.S. Cancer Statistics, the official federal cancer statistics.
U.S. Cancer Statistics Incidence data are from population-based registries that participate in CDC's National Program of Cancer Registries (NPCR) and the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Program. Data submitted in 2023 that met publication standards covered 99.6% of the U.S. population (excluding data from Indiana and Mississippi).
Footnotes
aRates are per 100,000 population and are age-adjusted to the 2000 U.S. standard population.
b2020 data were excluded from this trend analysis due to the effect of COVID-19 on data quality. The 2023 data submission, released in June 2024, includes new cancer cases diagnosed in 2020 and 2021, the first and second years of the COVID-19 pandemic. The missed cancer diagnoses resulting from disruptions in health services caused by the pandemic may have contributed to an observed decline in incidence for most cancer sites in 2020. The numbers of new cases diagnosed in 2021 are still lower than expected for some cancer types but have returned to pre-pandemic counts for other cancer types. Caution must be taken when examining trends to avoid incorrect interpretations of the effect of cancer prevention and early detection efforts. Observed downward trends may be due largely to the lower observed incidence in 2020.
*Average annual percent change (AAPC) is significantly different from zero (P < 0.05).