The mutation pattern of breast cancer molecular subtypes is incompletely understood. The purpose of this study was to identify mutations in genes that may be targeted with currently available investigational drugs in the three major breast cancer subtypes (ER+/HER2−, HER2+, and Triple Negative). We extracted DNA from fine needle aspirations of 267 stage I–III breast cancers. These tumor specimens typically consisted of >80 % neoplastic cells. We examined 28 genes for 163 known cancer-related nucleic acid variations by Sequenom technology. We observed at least one mutation in 38 alleles corresponding to 15 genes in 108 (40 %) samples, including PIK3CA (16.1 % of all samples), FBXW7 (8 %), BRAF (3.0 %), EGFR (2.6 %), AKT1 and CTNNB1 (1.9 % each), KIT and KRAS (1.5 % each), and PDGFR-α (1.1 %). We also checked for the polymorphism in PHLPP2 that is known to activate AKT and it was found at 13.5 % of the patient samples. PIK3CA mutations were more frequent in estrogen receptor-positive cancers compared to triple negative breast cancer (TNBC) (19 vs. 8 %, p = 0.001). High frequency of PIK3CA mutations (28 %) were also found in HER2+ breast tumors. In TNBC, FBXW7 mutations were significantly more frequent compared to ER+ tumors (13 vs. 5 %, p = 0.037). We performed validation for all mutated alleles with allele-specific PCR or direct sequencing; alleles analyzed by two different sequencing techniques showed 95–100 % concordance for mutation status. In conclusion, different breast cancer subtypes harbor different type of mutations and approximately 40 % of tumors contained individually rare mutations in signaling pathways that can be potentially targeted with drugs. Simultaneous testing of many different mutations in a single needle biopsy is feasible and allows the design of prospective clinical trials that could test the functional importance of these mutations in the future.

Purpose. To compare risk assignment by PAM50 Breast Cancer Intrinsic Classifier™ and Oncotype DX_Recur-rence Score (RS) in the same population.Methods. RNA was extracted from 151 estrogen receptor (ER) ؉ stage I-II breast cancers and gene expression profiled using PAM50 "intrinsic" subtyping test.Results. One hundred eight cases had complete molecular information; 103 (95%) were classified as luminal A (n ‫؍‬ 76) or luminal B (n ‫؍‬ 27). Ninety-two percent (n ‫؍‬ 98) had a low (n ‫؍‬ 59) or intermediate (n ‫؍‬ 39) RS. Among luminal A cancers, 70% had low (n ‫؍‬ 53) and the remainder (n ‫؍‬ 23) had an intermediate RS. Among luminal B cancers, nine were high (33%) and 13 were intermediate (48%) by the RS. Almost all cancers with a high RS were classified as luminal B (90%, n ‫؍‬ 9). One high RS cancer was identified as basal-like and had low ER/ESR1 and low human epidermal growth factor receptor 2 (HER2) expression by quantitative polymerase chain reaction in both assays. The majority of low RS cases were luminal A (83%, n ‫؍‬ 53). Importantly, half of the intermediate RS cancers were re-categorized as low risk luminal A subtype by PAM50.Conclusion. There is good agreement between the two assays for high (i.e., luminal B or RS > 31) and low (i.e., luminal B or RS < 18) prognostic risk assignment but PAM50 assigns more patients to the low risk category. About half of the intermediate RS group was reclassified as luminal A by PAM50. The Oncologist 2012;17:492-498

BACKGROUND:The purpose of the current study was to describe the outcomes of patients with human epidermal growth factor receptor 2 (HER2)-overexpressed=amplified (HER21) early breast cancer who received adjuvant or neoadjuvant trastuzumab-based therapy and were subsequently retreated with trastuzumab for metastatic disease. METHODS: A total of 353 patients with metastatic HER21 breast cancer who were treated with trastuzumab as part of their first-line treatment for metastatic disease were identified. A total of 75 patients had received adjuvant or neoadjuvant trastuzumab-based therapy for early breast cancer, and 278 had not. Clinical outcomes of patients who had or had not received prior trastuzumab were compared using Cox proportional hazards regression and logistic regression analyses. Survival was estimated using the Kaplan-Meier method. RESULTS: The clinical benefit (complete response, partial response, or stable disease of 6 months) rates were 71% in the group who did not receive prior trastuzumab and 39% in the group previously treated with trastuzumab. The adjusted odds ratios were 0.28 (95% confidence interval [95% CI], 0.13-0.59; P 5.0009) for clinical benefit rates and 0.39 (95% CI, 0.18-0.82; P 5.038) for objective (complete or partial) response rates. In the univariate analysis, the median overall survival rate was longer in the group who did not receive prior trastuzumab (36 months vs 28 months) (hazards ratio, 1.47; 95% CI, 1.07-2.01 [P 5.022]). The multivariate analysis found no significant difference in overall survival. CONCLUSIONS: When treated with trastuzumab for metastatic disease, patients with HER21 breast cancer without prior exposure to trastuzumab were found to have superior clinical outcomes to those with prior exposure. Prior trastuzumab exposure should be considered in treatment algorithms and in HER2-targeted clinical trial enrollment for metastatic disease. Cancer 2014;120:1932-8. KEYWORDS: human epidermal growth factor receptor 2 (HER2), trastuzumab, breast neoplasms, metastasis, outcomes, drug resistance. INTRODUCTIONThe human epidermal growth factor receptor 2 (HER2, also known as ERBB2) gene encodes a growth factor tyrosine kinase receptor that belongs to a family of 4 transmembrane receptor tyrosine kinases that mediate cell growth, differentiation, and survival. 1 The HER2 protein is overexpressed in 20% to 25% of invasive breast cancers, 2-4 and its overexpression portends an unfavorable prognosis because of its inherently more aggressive biology. 5,6 HER2 protein overexpression or HER2 gene amplification is associated with an increased metastatic potential and a decreased overall survival rate. 2 Previously, the most effective adjuvant systemic regimen for patients with HER2-positive breast cancer was a combination of anthracyclines and taxanes. 7 To our knowledge, trastuzumab was the first humanized monoclonal antibody that directly targeted the extracellular domain of the HER2 receptor. 8 Some of trastuzumab's antitumor effects are antibody-dependent cellular cytotoxici...

The aims of this study were to compare the performance of six different genomic prognostic markers to predict long-term survival and chemotherapy response on the same patient cohort and assess if clinicopathological variables carry independent prognostic and predictive values. We examined seven clinical variables and six previously described prognostic signatures on 228 tumors from patients who received homogeneous preoperative chemotherapy and had long-term follow-up information for survival. We used the area under the receiver operator characteristic curve (AUC) to compare predictors and also performed univariate and multivariate analyses including the genomic and clinical variables and plotted Kaplan-Meir survival curves. All genomic prognostic markers had statistically similar AUCs and sensitivity to predict 5-year progression-free survival (PFS, sensitivities ranged from 0.591 to 0.773, and AUCs: 0.599-0.673), overall survival (OS, sensitivities: 0.590-0.769, AUCs: 0.596-0.684) and pathologic complete response (pCR, sensitivities: 0.596-0.851, AUCs: 0.614-0.805). In multivariate analysis, the genomic markers were not independent from one another; however, estrogen receptor (Odds Ratio [OR] 7.63, P < 0.001) and HER2 status (OR: 0.37, P = 0.021) showed significant independent predictive values for pCR. Nodal status remained an independent prognostic, but not predictive, variable (OR for PFS: 2.77, P = 0.021, OR for OS: 3.62, P = 0.01). There was moderate to good agreement between different prediction results in pair-wise comparisons. First-generation prognostic-gene signatures predict both chemotherapy response and long-term survival. When multiple predictors are applied to the same case discordant risk prediction frequently occurs.

Bone is the most common site of metastasis of breast cancer, affecting most women with advanced disease. Procollagen type I N-terminal propeptide (P1NP), osteocalcin, CTX, and IL-6 are markers of bone turnover. Our objective was to determine whether serum levels of these proteins have clinical utility as predictors of breast cancer metastasis to bone. Blood was collected before treatment from 164 patients with stage I–III breast cancer from September 2001 to December 2008. erum levels of P1NP, CTX, IL-6, and OC were measured using an automated immunoassay system. Correlations of the levels of these markers with time to bone metastasis development and with overall survival (OS) rate were assessed using Cox proportional hazards regression analysis and the Kaplan–Meier method. Fifty-five patients with stage I–III disease at the time of blood sample collection subsequently experienced metastasis to bone. A baseline P1NP level of at least 75 ng/mL predicted increased risk of bone metastasis (hazard ratio, 2.7 [95 % confidence interval, 1.2–6.0]; P = 0.031) and a poor OS rate (P = 0.031). Serum P1NP levels at or above 75 ng/mL correlate with a short time to development of bone metastasis and low overall survival in patients with stage I–III breast cancer.