US incidence of breast cancer subtypes defined by joint hormone receptor and HER2 status.
BACKGROUND
In 2010, Surveillance, Epidemiology, and End Results (SEER) registries began collecting human epidermal growth factor 2 (HER2) receptor status for breast cancer cases.


METHODS
Breast cancer subtypes defined by joint hormone receptor (HR; estrogen receptor [ER] and progesterone receptor [PR]) and HER2 status were assessed across the 28% of the US population that is covered by SEER registries. Age-specific incidence rates by subtype were calculated for non-Hispanic (NH) white, NH black, NH Asian Pacific Islander (API), and Hispanic women. Joint HR/HER2 status distributions by age, race/ethnicity, county-level poverty, registry, stage, Bloom-Richardson grade, tumor size, and nodal status were evaluated using multivariable adjusted polytomous logistic regression. All statistical tests were two-sided.


RESULTS
Among case patients with known HR/HER2 status, 36810 (72.7%) were found to be HR(+)/HER2(-), 6193 (12.2%) were triple-negative (HR(-)/HER2(-)), 5240 (10.3%) were HR(+)/HER2(+), and 2328 (4.6%) were HR(-)/HER2(+); 6912 (12%) had unknown HR/HER2 status. NH white women had the highest incidence rate of the HR(+)/HER2(-) subtype, and NH black women had the highest rate of the triple-negative subtype. Compared with women with the HR(+)/HER2(-) subtype, triple-negative patients were more likely to be NH black and Hispanic; HR(+)/HER2(+) patients were more likely to be NH API; and HR(-)/HER2(+) patients were more likely to be NH black, NH API, and Hispanic. Patients with triple-negative, HR(+)/HER2(+), and HR(-)/HER2(+) breast cancer were 10% to 30% less likely to be diagnosed at older ages compared with HR(+)/HER2(-) patients and 6.4-fold to 20.0-fold more likely to present with high-grade disease.


CONCLUSIONS
In the future, SEER data can be used to monitor clinical outcomes in women diagnosed with different molecular subtypes of breast cancer for a large portion (approximately 28%) of the US population.
Affiliations of authors: Surveillance Research Program, Division of Cancer Control and Population Sciences, National Cancer Institute, Bethesda MD (NH, SFA, LAGR, KAC); Department of Epidemiology, University of Washington, Seattle, WA (CIL); Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA (CIL); Louisiana Tumor Registry and Epidemiology Program, School of Public Health, Louisiana State University Health Sciences Center, New Orleans, LA (VWC); Cancer Prevention Institute of California, Fremont, CA (CAC); National Cancer Institute Contractor, RiesSearch, LLC, Rockville MD (LAGR). howladern@mail.nih.gov.
Nadia
N
Howlader
Affiliations of authors: Surveillance Research Program, Division of Cancer Control and Population Sciences, National Cancer Institute, Bethesda MD (NH, SFA, LAGR, KAC); Department of Epidemiology, University of Washington, Seattle, WA (CIL); Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA (CIL); Louisiana Tumor Registry and Epidemiology Program, School of Public Health, Louisiana State University Health Sciences Center, New Orleans, LA (VWC); Cancer Prevention Institute of California, Fremont, CA (CAC); National Cancer Institute Contractor, RiesSearch, LLC, Rockville MD (LAGR).
Sean F
SF
Altekruse
Affiliations of authors: Surveillance Research Program, Division of Cancer Control and Population Sciences, National Cancer Institute, Bethesda MD (NH, SFA, LAGR, KAC); Department of Epidemiology, University of Washington, Seattle, WA (CIL); Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA (CIL); Louisiana Tumor Registry and Epidemiology Program, School of Public Health, Louisiana State University Health Sciences Center, New Orleans, LA (VWC); Cancer Prevention Institute of California, Fremont, CA (CAC); National Cancer Institute Contractor, RiesSearch, LLC, Rockville MD (LAGR).
Christopher I
CI
Li
Affiliations of authors: Surveillance Research Program, Division of Cancer Control and Population Sciences, National Cancer Institute, Bethesda MD (NH, SFA, LAGR, KAC); Department of Epidemiology, University of Washington, Seattle, WA (CIL); Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA (CIL); Louisiana Tumor Registry and Epidemiology Program, School of Public Health, Louisiana State University Health Sciences Center, New Orleans, LA (VWC); Cancer Prevention Institute of California, Fremont, CA (CAC); National Cancer Institute Contractor, RiesSearch, LLC, Rockville MD (LAGR).
Vivien W
VW
Chen
Affiliations of authors: Surveillance Research Program, Division of Cancer Control and Population Sciences, National Cancer Institute, Bethesda MD (NH, SFA, LAGR, KAC); Department of Epidemiology, University of Washington, Seattle, WA (CIL); Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA (CIL); Louisiana Tumor Registry and Epidemiology Program, School of Public Health, Louisiana State University Health Sciences Center, New Orleans, LA (VWC); Cancer Prevention Institute of California, Fremont, CA (CAC); National Cancer Institute Contractor, RiesSearch, LLC, Rockville MD (LAGR).
Christina A
CA
Clarke
Affiliations of authors: Surveillance Research Program, Division of Cancer Control and Population Sciences, National Cancer Institute, Bethesda MD (NH, SFA, LAGR, KAC); Department of Epidemiology, University of Washington, Seattle, WA (CIL); Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA (CIL); Louisiana Tumor Registry and Epidemiology Program, School of Public Health, Louisiana State University Health Sciences Center, New Orleans, LA (VWC); Cancer Prevention Institute of California, Fremont, CA (CAC); National Cancer Institute Contractor, RiesSearch, LLC, Rockville MD (LAGR).
Lynn A G
LA
Ries
Affiliations of authors: Surveillance Research Program, Division of Cancer Control and Population Sciences, National Cancer Institute, Bethesda MD (NH, SFA, LAGR, KAC); Department of Epidemiology, University of Washington, Seattle, WA (CIL); Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA (CIL); Louisiana Tumor Registry and Epidemiology Program, School of Public Health, Louisiana State University Health Sciences Center, New Orleans, LA (VWC); Cancer Prevention Institute of California, Fremont, CA (CAC); National Cancer Institute Contractor, RiesSearch, LLC, Rockville MD (LAGR).
Kathleen A
KA
Cronin
D000368:Aged; D044383:Black People; D001943:Breast Neoplasms / Q000145:classification* / Q000453:epidemiology* / Q000208:ethnology / Q000378:metabolism; D005260:Female; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000096:biosynthesis*; D011960:Receptors, Estrogen / Q000096:biosynthesis*; D011980:Receptors, Progesterone / Q000096:biosynthesis*; D012042:Registries; D018426:SEER Program; D064726:Triple Negative Breast Neoplasms / Q000145:classification* / Q000453:epidemiology* / Q000208:ethnology / Q000378:metabolism; D014481:United States / Q000453:epidemiology; D044465:White People; D001741:Black or African American
D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; C508053:ERBB2 protein, human