Features of triple-negative breast cancer: Analysis of 38,813 cases from the national cancer database.

The aim of this study was to determine the features of triple-negative breast cancer (TNBC) using a large national database. TNBC is known to be an aggressive subtype, but national epidemiologic data are sparse. All patients with invasive breast cancer and known molecular subtype diagnosed in 2010 to 2011 were identified from the National Cancer Data Base (NCDB). Patients with and without TNBC were compared with respect to their sociodemographic and clinicopathologic features. TNBC was present in 38,628 of 295,801 (13%) female patients compared to 185 of 3136 (6%) male patients (P < 0.001). The incidence of TNBC varied by region from 10.8% in New England to 15.8% in the east south central US (P < 0.001), as well as by race with the highest rates in African-Americans (23.7%), and lowest in Filipino patients (8.9%). The incidence of TNBC also varied by histology, accounting for 76% of metaplastic cancers, but only 2% of infiltrating lobular carcinomas. TNBCs were significantly larger than non-TNBC (mean 2.8 cm vs 2.1 cm, P < 0.001), and more TNBC were poorly differentiated compared to other subtypes (79.7% vs 25.8%, P < 0.001). On univariate analysis, TNBC was no more likely than non-TNBC to have node-positive disease (32.0% vs 31.7%, respectively, P = 0.218) but in a multivariable analysis controlling for tumor size and grade, TNBC was associated with significantly less node-positivity (OR = 0.59; 95% confidence interval [CI]: 0.57-0.60). TNBC has distinct features regarding age, gender, geographic, and racial distribution. Compared to non-TNBC, TNBC is larger and higher grade, but less likely to have lymph node metastases.

Breast cancer biology varies by method of detection and may contribute to overdiagnosis.

BACKGROUND: Recently, it has been suggested that screening mammography may result in some degree of overdiagnosis (ie, detection of breast cancers that would never become clinically important within the lifespan of the patient). The extent and biology of these overdiagnosed cancers, however, is not well understood, and the effect of newer screening modalities on overdiagnosis is unknown. METHODS: We performed a retrospective review of a prospectively collected database of breast cancers diagnosed at the Yale Breast Center from 2004-2014. The mode of initial presentation was categorized into 5 groups: screening mammogram, screening magnetic resonance imaging, screening ultrasonography, self-detected masses, and physician-detected masses. RESULTS: Compared with cancers presenting with masses, cancers detected by image-based screening were more likely to present with ductal carcinoma-in-situ or T1 cancers (P < .001). In addition to a simple stage shift, however, cancers detected by image-based screening were also more likely to be luminal and low-grade cancers; symptomatic cancers were more likely high-grade and triple-negative (P < .001, respectively). On a multivariate analysis, adjusting for age, race, and tumor size, cancers detected by mammogram, US, and magnetic resonance imaging had greater odds of being luminal (odds ratio 1.8, 95% confidence interval, 1.5-2.3; odds ratio 2.2, 95% confidence interval, 1.1-4.7; and odds ratio 4.7, 95% confidence interval, 2.1-10.6, respectively), and low-grade (odds ratio 2.2, 95% confidence interval, 1.6-2.9; odds ratio 4.9, 95% confidence interval, 2.7-8.9; and odds ratio 4.6, 95% confidence interval, 2.6-8.1, respectively) compared with cancers presenting with self-detected masses. CONCLUSION: Screening detects cancers with more indolent biology, potentially contributing to the observed rate of overdiagnosis. With magnetic resonance imaging and US being used more commonly for screening, the rate of overdiagnosis may increase further.

Racial Differences in the Use and Outcome of Neoadjuvant Chemotherapy for Breast Cancer: Results From the National Cancer Data Base.

PURPOSE: To explore racial differences in the use and outcome of neoadjuvant chemotherapy for breast cancer. METHODS: The National Cancer Data Base was queried to identify women with stage 1 to 3 breast cancer diagnosed in 2010 and 2011. Chemotherapy use and rate of pathologic complete response (pCR) was determined for various racial/ethnic groups. RESULTS: Of 278,815 patients with known race and ethnicity, 127,417 (46%) received chemotherapy, and of 121,446 where the timing of chemotherapy was known, 27,300 (23%) received neoadjuvant chemotherapy. Chemotherapy, and neoadjuvant chemotherapy in particular, was given more frequently to black, Hispanic, and Asian women than to white women (P < 0.001). This difference was largely explained by more advanced stage, higher grade tumors, and a greater proportion of triple-negative and human epidermal growth factor receptor 2 (HER2)-positive tumors in these women. Of 17,970 patients with known outcome, 5,944 (33%) had a pCR. No differences in response rate for estrogen receptor (ER)/progesterone receptor (PR)-positive tumors were found, but compared with white women, black but not Hispanic or Asian women had a lower rate of pCR for ER/PR-negative, HER2-positive (43% v 54%, P = 0.001) and triple-negative tumors (37% v 43%, P < 0.001). This difference persisted when adjusted for age, clinical T stage, clinical N stage, histology, grade, comorbidity index, facility type, geographic region, insurance status, and census-derived median income and education for the patient's zip code (odds ratio, 0.84; 95% CI, 0.77 to 0.93). CONCLUSION: Neoadjuvant chemotherapy is given more frequently to black, Hispanic, and Asian women than to white women. Black women have a lower likelihood of pCR for triple-negative and HER2-positive breast cancer. Whether this is due to biologic differences in chemosensitivity or to treatment or socioeconomic differences that could not be adjusted for is unknown.

Characteristics of Multifocal and Multicentric Breast Cancers.

BACKGROUND: Multifocality and multicentricity are increasingly recognized in breast cancer. However, little is known about the characteristics and biology of these cancers and the clinical implications are controversial. METHODS: A retrospective, institutional database was used to compare characteristics of multifocal (MF) and multicentric (MC) breast cancers with unifocal (UF) cancers to study concordance of histology and receptor status among primary and secondary foci and to evaluate predictors of lymph node positivity using multivariate logistic regression. RESULTS: Of 1495 invasive cancers, 1231 (82.3 %) were UF, 169 (11.3 %) were MF, and 95 (6.4 %) were MC cancers. When MF and MC cancers were compared with UF cancers, MC but not MF cancers were associated with young age at diagnosis, larger tumor size, lymphovascular invasion, and node positivity. MF but not MC tumors were more likely to be ER/PR+Her2+ tumors and less likely to be triple-negative cancers compared with UF tumors. MF tumors were more likely to be infiltrating ductal carcinomas with an extensive intraductal component, and MC tumors were more likely to be infiltrating lobular carcinomas. Concordance of histology and receptor status between primary and secondary foci was high and was similar for both MF and MC cancers. Multicentricity remained an independent predictor of lymph node positivity on multivariate analysis. CONCLUSION: MF and MC tumors seem to be biologically different diseases. MC is clinicopathologically more aggressive than MF disease and is more frequently associated with younger age and larger tumor size and also is an independent predictor of node positivity.