Age/race differences in HER2 testing and in incidence rates for breast cancer triple subtypes

Abstract

BACKGROUND: Although US year 2000 guidelines recommended characterizing breast cancers by human epidermal growth factor receptor 2 (HER2), national cancer registries do not collect HER2, rendering a population-based understanding of HER2 and clinical ''triple subtypes'' (estrogen receptor [ER] / progesterone receptor [PR] / HER2) largely unknown. We document the population-based prevalence of HER2 testing / status, triple subtypes and present the first report of subtype incidence rates. METHODS: Medical records were searched for HER2 on 1842 metropolitan Atlanta females diagnosed with breast cancer during [2003][2004]. HER2 testing/status and triple subtypes were analyzed by age, race/ethnicity, tumor factors, socioeconomic status, and treatment. Age-adjusted incidence rates were calculated. RESULTS: Over 90% of cases received HER2 testing: 12.6% were positive, 71.7% negative, and 15.7% unknown. HER2 testing compliance was significantly better for women who were younger, of Caucasian or African-American descent, or diagnosed with early stage disease. Incidence rates (per 100,000) were 21.1 for HER2þ tumors and 27.8 for triple-negative tumors, the latter differing by race (36.3 and 19.4 for black and white women, respectively). CONCLUSIONS: HER2 recommendations are not uniformly adhered to. Incidence rates for breast cancer triple subtypes differ by age/race. As biologic knowledge is translated into the clinical setting eg, HER2 as a biomarker, it will be incumbent upon national cancer registries to report this information. Incidence rates cautiously extrapolate to an annual burden of 3000 and 17,000 HER2þ tumors for black and white women, respectively, and triple-negative tumors among 5000 and 16,000 respectively. Testing, rate, and burden variations warrant population-based in-depth exploration and clinical translation.

Familial Breast Cancer Registry Program in Patients Referred to the Cancer Institute of Iran

“…TNBC is a more invasive cancer with higher degree of recurrence. About 14 to 20 percentages of breast cancers are triple negative (Carey et al, 2006;Hannemann et al, 2006;Lund et al, 2010). Similar to our study, the significant increase of the triple negative tumors with decrease of cancer onset age has been shown in many other studies in different countries that TNBC has been more frequent in younger ages (Dobi et al, 2011;Salami et al, 2011).…”

Triple-negative breast cancer in Hispanic patients

“…This prevalence was higher than that reported in white patients (range, 10%-13%) but was closer to the prevalence reported in African-American patients (range, 23%-30%). 14,30 Few studies have been performed on Hispanics living in the United States. In a small study of 46 patients, the prevalence of TNBC was 10%, 14 although this low prevalence may not be representative because of the small sample size.…”

Female Breast Cancer Status According to ER, PR and HER2 Expression: A Population Based Analysis

“…Since 2000 characterization of breast cancer, apart from expression of biomarkers for estrogen receptors (ER) and progesterone receptors (PR), has included also the human epidermal growth factor 2 (HER2) [1].…”

“…Several recent studies have identified different subtypes of morphologically similar breast cancer patients with different prognosis and different therapeutic response through the evaluation of the combination of ER, PR and HER2 status, currently reported in routine pathology reports of breast cancer [1,5,6].…”