Abstract P6-06-30: Are synchronous and metachronous bilateral breast cancers different? An immunohistochemical analysis aimed at intrinsic tumor phenotype

Background: The biology and pathomechanism of bilateral breast cancers is not fully understood: the risk of developing second (metachronous) breast cancer is 4-6 times higher than that of first primary in general population, whereas for synchronous breast cancers the number of cases is about 100 times higher than could be expected by chance alone. We compared the morphological and immunohistochemical characteristics of primary synchronous (sBBC) vs. metachronous (mBBC) bilateral breast cancers), with special focus on intrinsic tumor phenotype.

Methods: Tumor morphology and expression of 8 immunohistochemical markers were assessed in tissue microarrays containing primary breast tumor cores from 113 mBBC and 61 sBBC. Analyzed markers included hormone receptors (estrogen receptor, progesterone receptor), HER2, Ki67, cytokeratin 5/6, E-cadherin, vimentin and epidermal growth factor receptor. Surrogate intrinsic phenotypes were determined according to St Gallen 2011 criteria.

Results: mBBChad higher incidence of ductal histology (p = 0.037), lower estrogen receptor expression (p = 0.047), and higher expression of cytokeratin 5/6 (p = 0.017) and of vimentin (p = 0.008); in multivariate analysis only vimentin retained the significance (p = 0.01). Ten (13%) and 11 (26%) of mBBCand sBBC, respectively, had luminal A phenotype, 39 (50%) and 15 (36%) were luminal B HER2-negative, 13 (17%) and 12 (28%) - luminal B HER2-positive, 3 (4%) and 2 (5%) - HER2-positive (not luminal), and 12 (16%) and 2 (5%) had triple negative phenotype (p = 0.07).

Characteristics of mBBC and sBBCFeaturemBBC (%)sBBC (%)p valueDuctal histology98 (87)47 (77)0.037Grade 346 (41)17 (28)0.09Extensive intraductal component26 (23)18 (29)0.42Strong ER expression73 (67)48 (81)0.047Strong PR expression55 (49)38 (63)0.07HER2 positivity (2+, 3+)51 (46)29 (50)0.6Ki76 ≤14%24 (22)21 (35)0.06Surrogate intrinsic phenotype   luminal A10 (13)11 (26) luminal B HER2-39 (50)15 (36) luminal B HER2+13 (17)12 (28)0.07triple negative12 (16)2 (5) HER2+ (non luminal)3 (4)2 (5) CK5/6 >10%28 (26)6 (11)0.017Vimentin >10%25 (23)4 (7)0.008E-cadherin (+)88 (83)49 (83)0.99EGFR (+)35 (32)11 (19)0.07

Conclusion: mBBC, compared to sBBC, are characterized by more aggressive phenotype, expressed by lower expression of estrogen receptor and stronger expression of cytokeratin /6 and vimentin; this does not, however, translate into substantial differences in the proportion of intrinsic tumor phenotypes.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-06-30.

Acute Cerebrovascular Disease in the Young

Background and Purpose—

Strokes have especially devastating implications if they occur early in life; however, only limited information exists on the characteristics of acute cerebrovascular disease in young adults. Although risk factors and manifestation of atherosclerosis are commonly associated with stroke in the elderly, recent data suggests different causes for stroke in the young. We initiated the prospective, multinational European study Stroke in Young Fabry Patients (sifap) to characterize a cohort of young stroke patients.

Methods—

Overall, 5023 patients aged 18 to 55 years with the diagnosis of ischemic stroke (3396), hemorrhagic stroke (271), transient ischemic attack (1071) were enrolled in 15 European countries and 47 centers between April 2007 and January 2010 undergoing a detailed, standardized, clinical, laboratory, and radiological protocol.

Results—

Median age in the overall cohort was 46 years. Definite Fabry disease was diagnosed in 0.5% (95% confidence interval, 0.4%–0.8%; n=27) of all patients; and probable Fabry disease in additional 18 patients. Males dominated the study population (2962/59%) whereas females outnumbered men (65.3%) among the youngest patients (18–24 years). About 80.5% of the patients had a first stroke. Silent infarcts on magnetic resonance imaging were seen in 20% of patients with a first-ever stroke, and in 11.4% of patients with transient ischemic attack and no history of a previous cerebrovascular event. The most common causes of ischemic stroke were large artery atherosclerosis (18.6%) and dissection (9.9%).

Conclusions—

Definite Fabry disease occurs in 0.5% and probable Fabry disease in further 0.4% of young stroke patients. Silent infarcts, white matter intensities, and classical risk factors were highly prevalent, emphasizing the need for new early preventive strategies.

Clinical Trial Registration Information—

URL: http://www.clinicaltrials.gov .Unique identifier: NCT00414583

Predictors of brain relapse in HER-2 positive metastatic breast cancer (MBC) patients (pts)

10508

Background: Brain relapse is a common occurrence in HER2-positive breast cancer pts. We assessed factors determining the risk of this event in a large unselected series of HER2-positive MBC pts. Methods: Study group included 233 consecutive HER2-positive (IH 3+ or FISH+) MBC pts (median age 53 years); 49% premenopausal, 49% postmenopausal and 2% with unknown menopausal status. Dominant site of disease included viscera (78%), soft tissue (11%) and bones (10%). Of the 206 pts (88%) with known steroid receptor status, ER+/PgR+, ER+/PgR-, ER-/PgR+, ER-/PgR- phenotypes included 58%, 15%, 5% and 21% of pts, respectively. Prior (neo)adjuvant chemotherapy, endocrine therapy or a combination thereof was administered in 40%, 6% and 35% of pts, respectively. Disease-free interval to the development of MBC ranged between 0 and 142 months (median 16 months). 184 pts (79%) received trastuzumab for MBC, usually in combination with chemotherapy. Statistical analysis included contingency tables, chi-square test, Kaplan-Meier survival analysis and Cox proportional hazard model. Results: Median follow-up from the development of MBC was 25 months (range 0.5–130 months). 54 pts (23%) developed brain metastases after a median of 13 months (range, 0 to 81 months). Cumulative risk of brain relapse was 11% (95% CI: 7–16%) and 24% (95% CI: 17–32%) at one and two years, respectively. Trastuzumab treatment was associated with insignificantly reduced risk of brain metastases (HR 0.63, 95% CI 0.29–1.39, p = 0.25). In the univariate analysis, premenopausal status was the only significant factor associated with increased risk of brain relapse (HR 2.56, 95% CI 1.28–5.00, p = 0.008). Conclusion: HER-2 positive MBC pts carry high risk of brain relapse, in particular prior to menopause. Protective role of trastuzumab warrants further research.

[Table: see text]