HER2-positive Breast Cancer Epidemiology
BREAST CANCER
- According to the American Cancer Society and National Cancer Institute, the current estimates for breast cancer for the year 2020 include:1,2
- Incidence of female breast cancer estimated to be 276,480 new cases.2,3
- About 48,530 new cases of carcinoma in situ (CIS) will be diagnosed (CIS is non-invasive and is the earliest form of breast cancer).2
- About 42,170 women will die from breast cancer.2,3
- Breast cancer is the second leading cause of cancer death in women (only lung cancer kills more women each year), accounting for approximately 7% of all cancer deaths.3 The chance that a woman will die from breast cancer is about 1 in 38 (about 2.6%).2
- Since 2007, breast cancer death rates have been steady in women younger than 50 but have continued to decrease in older women. From 2013 to 2017, the death rate decreased by 1.3% per year.2
- These decreases are believed to be the result of finding breast cancer earlier through screening and increased awareness, as well as better treatments.2
HER2-positive (HER2+) BREAST CANCER
- Breast cancer is classified into four main subtypes, utilizing hormone receptor and HER2 receptor status for differentiation.1
- HER2+ breast cancers comprise two of these subtypes, distinguished by hormone receptor status – hormone receptor positive (HR+), also known as “Luminal B” and hormone receptor negative (HR-), also known as “HER2-enriched”. 1
- These two breast cancer subtypes account for 18.8 new breast cancer cases per 100,000 women, with the majority being HR+ (HR+ = 13.3 and HR- = 5.5).1
- In comparison of different subtypes, HER2+ breast cancers only constitute 14% of all female breast cancer cases.1
- Survival rates for HER2+ breast cancers can vary by subtype:
- The 5-year relative survival of patients with HR+/HER2+ breast cancers is 90.4%, the second-best survival of all women with breast cancer.1
- Although this subtype is the least common, the 5-year relative survival of patients with HR-/HER2+ breast cancers is 83.6%.1
- Staging of disease can significantly impact 5-year relative survival rates:
- Relative survival of HR+/HER2+ breast cancer patients is 98.7% if disease is localized, 89.5% if disease is regional and 43.5% if disease is distant.1
- Similarly, relative survival of HR-/HER2+ breast cancer patients is 96.1% if disease is localized, 81.7% if disease is regional and 36.8% if disease is distant.1
- Incidence of HER2+ breast cancers can also vary by ethnicity:
- HR+/HER2+ ethnic/race distribution (out of every 100,000 women diagnosed with breast cancer): 13.3 (White), 13.3 (Black), 8.6 (American Indian/Alaska Native), 12.2 (Asian/Pacific Islander) and 11.0 (Hispanic).1
- HR-/HER2+ ethnic/race distribution (out of every 100,000 women diagnosed with breast cancer: 5.2 (White), 6.6 (Black), 4.5 (American Indian/Alaska Native), 5.9 (Asian/Pacific Islander) and 4.9 (Hispanic)1.
Sources and Additional Reading
- National Cancer Institute, Surveillance, Epidemiology, and End Results Program. Cancer Stat Facts: Female Breast Cancer Subtypes. Available: https://seer.cancer.gov/statfacts/html/breast-subtypes.html. Accessed June 2020.
- American Cancer Society, How Common Is Breast Cancer? Available: https://www.cancer.org/cancer/breast-cancer/about/how-common-is-breast-cancer.html. Accessed June 2020.
- National Cancer Institute, Surveillance, Epidemiology, and End Results Program. Cancer Stat Facts: Cancer Stat Facts: Female Breast Cancer. Available: https://seer.cancer.gov/statfacts/html/breast.html. Accessed June 2020.