Katrina R. Bauer

Descriptive analysis of estrogen receptor (ER)-negative, progesterone receptor (PR)-negative, and HER2-negative invasive breast cancer, the so-called triple-negative phenotype: A population-based study from the California Cancer Registry

Tumor markers are becoming increasingly important in breast cancer research because of their impact on prognosis, treatment, and survival, and because of their relation to breast cancer subtypes. The triple‐negative phenotype is important because of its relation to the basal‐like subtype of breast cancer.

The Impact of Socioeconomic Status on Survival After Cancer in the United States : Findings From the National Program of Cancer Registries Patterns of Care Study

Understanding the ways in which socioeconomic status (SES) affects mortality is important for defining strategies to eliminate the unequal burden of cancer by race and ethnicity in the United States.

Breast Cancer Subtypes as Defined by the Estrogen Receptor (ER), Progesterone Receptor (PR), and the Human Epidermal Growth Factor Receptor 2 (HER2) among Women with Invasive Breast Cancer in California, 1999–2004

Abstract:  Breast cancer research examining either molecular profiles or biomarker subtypes has focused on the estrogen receptor negative/progesterone receptor negative/human epidermal growth factor receptor 2 negative (ER−/PR−/HER2−) and ER−/PR−/HER2+ subtypes. Less is known about the epidemiology or clinical outcome of the other subtypes. This study examines the eight combinations of ER/PR/HER2 in patients with invasive breast cancer. The 5‐year relative survival and the distribution among demographic, socioeconomic, and tumor characteristics of each of the subtypes are examined. Using the California Cancer Registry, 61,309 women with primary invasive breast cancer were classified according to ER/PR/HER2 status. Five‐year relative survival was computed for the eight subtypes. Bivariate analyses were used to assess the distribution of cases across all subtypes. Multivariate logistic regression was used to compute the adjusted odds of having one of the five subtypes with the best and worst survival. Survival varied from 96% (ER+/PR+/HER2−) to 76% (ER−/PR−/HER2+ and ER−/PR−/HER2−). The four subtypes with the poorest survival were all ER negative. Women who were younger than age 50, non‐Hispanic black or Hispanic, of the lowest SES groups, and had stage IV tumors that were undifferentiated were overrepresented in ER−/PR−/HER2+ and triple negative (ER−/PR−/HER2−) subtypes. Asian Pacific Islanders had increased odds (OR = 1.41; 95% confidence interval [CI] = 1.26–1.57) of having the ER−/PR−/HER2+ subtype. Stage III tumors (OR = 1.25; 95% CI = 1.08–1.44) and stage IV tumors (OR = 1.58; 95% CI = 1.27–1.98) had higher odds than stage I tumors of being ER−/PR−/HER2+. Stage IV tumors (OR = 0.54; 95% CI = 0.44–0.67) strongly decreased the odds of the ER−/PR−/HER2− subtype. Poorly differentiated and undifferentiated tumors were over 20 times as likely as well‐differentiated tumors of being ER−/PR−/HER2− or ER−/PR−/HER2+. There are considerable differences in survival, demographics, and tumor characteristics among the eight subtypes. We recommend reporting breast cancer as an ER/PR/HER2 subtype and precisely documenting demographic and tumor characteristics.

The role of human epidermal growth factor receptor 2 in the survival of women with estrogen and progesterone receptor‐negative, invasive breast cancer: The California Cancer Registry, 1999–2004

Breast cancers that are negative for estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) (triple negative [TN]) have been associated with high‐grade histology, aggressive clinical behavior, and poor survival. It has been determined that breast cancers that are negative for ER and PR but positive for HER2 (double negative [DN]) share features with TN breast cancers. In this report, the authors quantified the contribution of HER2 as well as demographic and tumor characteristics to the survival of women with TN tumors, DN tumors, and other breast cancers (OBC).

Variation in breast cancer subtypes with age and race/ethnicity

BACKGROUND Both age and race have been identified as independent predictors of breast cancer subtype but the association of age with subtype within each race is not well understood. This study assesses the association of age with the eight breast cancer subtypes as defined by ER/PR/HER2 among white, African-American, Hispanic, and Asian/Pacific Islander women. METHODS This study included 69,358 women with primary invasive breast cancer. Logistic regression was used to assess the association of age with each of the ER/PR/HER2 subtypes for each race adjusted for socioeconomic status, stage, grade, and tumor size. RESULTS The odds of African-American women having a triple-negative tumor were not statistically significantly increased for women under 46 when compared to the African-American women aged 46-69 (OR=0.96; 95% CI=0.80-1.16). A similar pattern was observed for the ER-/PR-/HER2+ subtype. Hispanic women under age 46 (OR=0.83; 95% CI=0.71-0.97) and over age 70 (OR=0.71; 95% CI=0.57-0.89) were less likely to have the ER-/PR-/HER2+ subtype. Asian/Pacific Islander women under age 46 also had reduced odds (OR=0.67; 95% CI=0.55-0.82) of the ER-/PR-/HER2+ subtype. CONCLUSIONS The ER/PR/HER2 subtypes vary with age and differences in this variation depend on race. It is important to define breast cancer using the ER/PR/HER2 subtype and the significance of age and race should not be overlooked.

Use of ER/PR/HER2 subtypes in conjunction with the 2007 St Gallen Consensus Statement for early breast cancer

BackgroundThe 2007 St Gallen international expert consensus statement describes three risk categories and provides recommendations for treatment of early breast cancer. The set of recommendations on how to best treat primary breast cancer is recognized and used by clinicians worldwide. We now examine the variability of five-year survival of the 2007 St Gallen Risk Classifications utilizing the ER/PR/HER2 subtypes.MethodsUsing the population-based California Cancer Registry, 114,786 incident cases of Stages 1-3 invasive breast cancer diagnosed between 2000 and 2006 were identified. Cases were assigned to Low, Intermediate, or High Risk categories. Five-year-relative survival was computed for the three St Gallen risk categories and for the ER/PR/HER2 subtypes for further differentiation.Results and DiscussionThere were 9,124 (13%) cases classified as Low Risk, 44,234 (65%) cases as Intermediate Risk, and 14,340 (21%) as High Risk. Within the Intermediate Risk group, 33,735 (76%) were node-negative (Intermediate Risk 2) and 10,499 (24%) were node-positive (Intermediate Risk 3). For the High Risk group, 6,149 (43%) had 1 to 3 positive axillary lymph nodes (High Risk 4) and 8,191 (57%) had four or more positive lymph nodes (High Risk 5).Using five-year relative survival as the principal criterion, we found the following: a) There was very little difference between the Low Risk and Intermediate Risk categories; b) Use of the ER/PR/HER2 subtypes within the Intermediate and High Risk categories separated each into a group with better five-year survival (ER-positive) and a group with worse survival (ER-negative), irrespective of HER2-status; c) The heterogeneity of the High Risk category was most evident when one examined the ER/PR/HER2 subtypes with four or more positive axillary lymph nodes; (d) HER2-positivity did not always translate to worse survival, as noted when one compared the triple positive subtype (ER+/PR+/HER2+) to the triple negative subtype (ER-/PR-/HER2-); and (e) ER-negativity appeared to be a stronger predictor of poor survival than HER2-positivity.ConclusionThe use of ER/PR/HER2 subtype highlights the marked heterogeneity of the Intermediate and High Risk categories of the 2007 St Gallen statements. The use of ER/PR/HER2 subtypes and correlation with molecular classification of breast cancer is recommended.

Disparities in receipt of adjuvant radiation therapy after breast-conserving surgery among the cancer-reporting regions of California

Incidence and mortality of breast cancer vary according to demographic factors such as age, race/ethnicity, socioeconomic status (SES), and geographic region. This study assesses the variation of these factors in the use of adjuvant radiation therapy (RT) after breast‐conserving surgery (BCS) among 8 regions of California.

Incidence of first primary central nervous system tumors in California, 2001-2005

We examined the incidence of first primary central nervous system tumors (PCNST) in California from 2001–2005. This study period represents the first five years of data collection of benign PCNST by the California Cancer Registry. California’s age-adjusted incidence rates (AAIR) for malignant and benign PCNST (5.5 and 8.5 per 100,000, respectively). Malignant PCNST were highest among non-Hispanic white males (7.8 per 100,000). Benign PCNST were highest among African American females (10.5 per 100,000). Hispanics, those with the lowest socioeconomic status, and those who lived in rural California were found to be significantly younger at diagnosis. Glioblastoma was the most frequent malignant histology, while meningioma had the highest incidence among benign histologies (2.6 and 4.5 per 100,000, respectively). This study is the first in the US to compare malignant to benign PCNST using a population-based data source. It illustrates the importance of PCNST surveillance in California and in diverse communities.

P.6 Breast cancer subtypes in elderly women

Background: ER and PR are known to be age-related, and it is postulated that HER2 expression is inversely related to hormone receptors. Much less is known about the breast cancer subtypes, as defined by ER, PR, and HER2, in elderly patients. Methods: Using the population-based California Cancer Registry, we identified 66,031 women diagnosed with primary invasive breast cancer between 1999 and 2004. We examined differences in the eight breast cancer subtypes in relation to age groups, race/ethnicity, socioeconomic status, stage at diagnosis, tumor grade, and relative survival. Results: Themost common subtype is ER-positive, PR-positive, HER2negative (+/+/–) occurring in 53.2% of the study population but with wide variation by age. Only 38.3% of patients 80 years of age are of this subtype. ER-positivity did not increase with age in all subtypes. The ER-positive, PR-positive, HER2-positive (+/+/+) subtype constitutes 15.6% of the 80 age group. The least common ER-positive subtype (+/–/+) remains stable with age, representing 3.6% of the 80 age group. HER2-positive cancers constitute 22.6% of the total population, and HER2-positivity decreases with age in all subtypes except one. The ER-negative, PR-negative, HER2-positive (–/–/+) subtype, corresponding to the molecularly defined HER2-overexpressing subtype, decreases with age, from 10.8% in the 80 age group. The triple negative subtype (–/–/–), found in 13.2% of the total population, represents 22.8% of the 80 age group. Almost one-third of all black patients 70 age group, 16.8% of blacks had the triple negative subtype whereas only 8.6% of whites had this subtype. Overall five-year relative survival was best in patients >70 years of age, and important differences in race/ethnicity, stage at diagnosis, and tumor grade were noted with increasing age. Some representative subtypes and age groups are shown below.