PURPOSE To determine whether the Recurrence Score (RS) provided independent information on risk of distant recurrence (DR) in the tamoxifen and anastrozole arms of the Arimidex, Tamoxifen, Alone or in Combination (ATAC) Trial. PATIENTS AND METHODS RNA was extracted from 1,372 tumor blocks from postmenopausal patients with hormone receptor-positive primary breast cancer in the monotherapy arms of ATAC. Twenty-one genes were assessed by quantitative reverse transcriptase polymerase chain reaction, and the RS was calculated. Cox proportional hazards models assessed the value of adding RS to a model with clinical variables (age, tumor size, grade, and treatment) in node-negative (N0) and node-positive (N+) women. RESULTS Reportable scores were available from 1,231 evaluable patients (N0, n = 872; N+, n = 306; and node status unknown, n = 53); 72, 74, and six DRs occurred in N0, N+, and node status unknown patients, respectively. For both N0 and N+ patients, RS was significantly associated with time to DR in multivariate analyses (P < .001 for N0 and P = .002 for N+). RS also showed significant prognostic value beyond that provided by Adjuvant! Online (P < .001). Nine-year DR rates in low (RS < 18), intermediate (RS = 18 to 30), and high RS (RS > or = 31) groups were 4%, 12%, and 25%, respectively, in N0 patients and 17%, 28%, and 49%, respectively, in N+ patients. The prognostic value of RS was similar in anastrozole- and tamoxifen-treated patients. CONCLUSION This study confirmed the performance of RS in postmenopausal HR+ patients treated with tamoxifen in a large contemporary population and demonstrated that RS is an independent predictor of DR in N0 and N+ hormone receptor-positive patients treated with anastrozole, adding value to estimates with standard clinicopathologic features.

ROR provides more prognostic information in endocrine-treated patients with ER-positive, node-negative disease than RS, with better differentiation of intermediate- and higher-risk groups.

Most estrogen receptor α (ER)-positive breast cancers initially respond to antiestrogens, but many eventually become estrogen-independent and recur. We identified an estrogen-independent role for ER and the CDK4/Rb/E2F transcriptional axis in the hormone-independent growth of breast cancer cells. ER downregulation with fulvestrant or siRNA inhibited estrogen-independent growth. Chromatin immunoprecipitation identified ER genomic binding activity in estrogen-deprived cells and primary breast tumors treated with aromatase inhibitors. Gene expression profiling revealed an estrogen-independent, ER/E2F-directed transcriptional program. An E2F activation gene signature correlated with a lesser response to aromatase inhibitors in patients' tumors. siRNA screening showed that CDK4, an activator of E2F, is required for estrogen-independent cell growth. Long-term estrogen-deprived cells hyperactivate phosphatidylinositol 3-kinase (PI3K) independently of ER/E2F. Fulvestrant combined with the pan-PI3K inhibitor BKM120 induced regression of ER+ xenografts. These data support further development of ER downregulators and CDK4 inhibitors, and their combination with PI3K inhibitors for treatment of antiestrogen-resistant breast cancers.

Aberrant promoter methylation and the associated loss of gene expression is a common accompaniment of human cancers. Nonetheless, it has been challenging to demonstrate in any given tumour that methylation of a specific gene was causal and not consequent to malignant transformation. In this regard, our attention was drawn to the genesis of gastric cancers in individuals with hereditary diffuse gastric cancer (HDGC). These individuals harbour germline mutations in the gene encoding E-cadherin, CDH1, but their cancers have consistently demonstrated absence of loss of heterozygosity at the CDH1 locus. These findings suggested the hypothesis that CDH1 promoter methylation might function as the 'second genetic hit' in the genesis of these cancers.

SUMMARY BACKGROUND Greater than 50% of recurrences in estrogen receptor-positive (ER+) breast cancer occur after 5 years of adjuvant endocrine therapy. Biomarkers capable of improving the risk-benefit of extended adjuvant endocrine therapy for these late recurrences would be clinically valuable. We compared the prognostic ability of the Breast Cancer Index (BCI), Oncotype DX Recurrence Score (RS) and IHC4 for both early and late recurrence among patients with ER+, node negative (N0) disease within the ATAC clinical trial. METHODS BCI was performed from 1102 primary tumor samples from ER+ patients and two versions (BCI-C (primary) and BCI-L (secondary), based on cubic and linear combinations of the variables) were evaluated. RS and IHC4 values were previously derived. Prognostic discrimination for early (<5y) and late recurrence (5–10y) was assessed. To evaluate the ability of the biomarkers to predict recurrence beyond standard clinicopathological parameters, the likelihood-ratio chi-square (LR-Δχ2) was calculated from Cox proportional hazards models. The primary endpoint was distant recurrence (DR). FINDINGS In the primary analysis of 665 ER+ N0 patients, categorical BCI-C demonstrated significant differences in risk of DR over 10 years (P<0·0001). In the secondary analysis, BCI-L proved to be a much stronger predictor, and BCI-L, IHC4 and RS had significant prognostic performance for early DR (BCI-L, p<0·0002), while only BCI-L was significant for late DR (LR-Δχ2: 7·97, p=0·0048). For risk of early DR at 5 years, BCI-L classified 59% (390/665), 25% (166/665) and 16% (109/665) of patients with 1.3% (0.5% – 3.1%), 5.6% (2.9% – 10.5%) and 18.1% (12.0% – 27.0%) for low, intermediate and high risk, respectively. For risk of late DR at 10 years, BCI-L classified 61% (366/596), 25% (146/596) and 14% (84/596) of patients with 3.5% (2.0% – 6.1%), 13.4% (8.5% – 20.8%) and 13.3% (7.4% – 23.4%) for low, intermediate and high, respectively. INTERPRETATION While all three biomarkers predicted for early DR, BCI-L was the only significant prognostic for risk of late DR. The three BCI-L groups identified two risk populations for both early and late DR with 84% (556/665) of patients having low risk for early DR, and a smaller population (39%, 230/596) having high risk for late DR who may benefit from extended endocrine or other therapy. FUNDING Avon Foundation, National Institutes of Health, Breast Cancer Foundation, DOD Breast Cancer Research Program, Susan G. Komen for the Cure, Breakthrough Breast Cancer through the Mary-Jean Mitchell Green Foundation, Astrazeneca, NIHR Biomedical Research Centre at the Royal Marsden.

The era of personalized medicine is likely to see an escalation in the use of biomarkers to ensure breast cancer patients receive optimal treatment. A combination of prognostic and predictive biomarkers should enable better quantification of the residual risk faced by patients and indicate the potential value of additional treatment. Established biomarkers such as estrogen receptor and progesterone receptor already play a significant role in the selection of patients for endocrine therapy. Human epidermal growth factor receptor 2 (HER2) is recognized as a strong predictor of response to trastuzumab whereas, more recently, the role of estrogen receptor and HER2 as negative and positive indicators for chemotherapy has also been explored. Ki67 has traditionally been recognized as a modest prognostic factor, but recent neoadjuvant studies suggest that on-treatment measurement may be a more effective predictor of treatment efficacy for both endocrine treatment and chemotherapy.The last decade has seen the emergence of numerous multigene expression profiles that aim to outdo traditional predictive and prognostic factors. The Oncotype DX assay and the MammaPrint profile are currently undergoing prospective clinical trials to clearly define their role. Other gene expression^based assays also show potential but are yet to be tested clinically. Rigorous comparison of these emerging markers with current treatment selection criteria will be required to determine whether they offer significant benefit to justify their use.

The initial development of diffuse gastric cancer (DGC) is poorly understood. The study of E-cadherin (CDH1) germ line mutation carriers predisposed to DGC provides a rare opportunity to elucidate the genetic and biological events surrounding disease initiation. Samples from various stages of hereditary and sporadic DGC were investigated to determine general mechanisms underlying early DGC development. Paraffin-embedded tissues from 13 CDH1 mutation carriers and from 10 sporadic early DGC cases were analyzed. Immunofluorescence and immunohistochemistry using differentiation, proliferation, and adhesion markers showed that DGC initiation seems to occur at the proliferative zone (the upper neck) of the gastric epithelium and correlates with absent or reduced expression of junctional proteins (B-actin, p120, Lin-7). Slow proliferation of neoplastic cells at the upper gastric neck leads to the formation of intramucosal signet-ring cell carcinoma (SRCC) displaying differentiated features. As shown by immunolabeling, invasion from SRCC lesions beyond the gastric mucosa is associated with poor differentiation, increased proliferation, activation of the c-Src system, and an epithelial-mesenchymal transition. Our results provide a molecular description of the early development of DGC and explain the relationship between the two main DGC types, poorly differentiated carcinoma and SRCC: both share their origin, but SRCC develops following cancer cell differentiation and seems relatively indolent in its intramucosal stage.

Purpose: Estrogen withdrawal by treatment with aromatase inhibitors is the most effective form of endocrine therapy for postmenopausal estrogen receptor-positive (ERþ) breast cancer. However, response to therapy varies markedly and understanding of the precise molecular effects of aromatase inhibitors and causes of resistance is limited. We aimed to identify in clinical breast cancer those genes and pathways most associated with resistance to aromatase inhibitors by examining the global transcriptional effects of AI treatment.Experimental Design: Baseline and 2-week posttreatment biopsies were obtained from 112 postmenopausal women with ERþ breast cancer receiving neoadjuvant anastrozole. Gene expression data were obtained from 81 baseline and 2-week paired samples. Pathway analysis identified (i) the most prevalent changes in expression and (ii) the pretreatment genes/pathways most related to poor antiproliferative response.Results: A total of 1,327 genes were differentially expressed after 2-week treatment (false discovery rate < 0.01). Proliferation-associated genes and classical estrogen-dependent genes were strongly downregulated whereas collagens and chemokines were upregulated. Pretreatment expression of an inflammatory signature correlated with antiproliferative response to anastrozole and this observation was validated in an independent study. Higher expression of immune-related genes such as SLAMF8 and TNF as well as lymphocytic infiltration were associated with poorer response (P < 0.001) and validated in an independent cohort.Conclusions: The molecular response to aromatase inhibitor treatment varies greatly between patients consistent with the variable clinical benefit from aromatase inhibitor treatment. Higher baseline expression of an inflammatory signature is associated with poor antiproliferative response and should be assessed further as a novel biomarker and potential target for aromatase inhibitor-treated patients.