Virginia G. Kaklamani

Prospective validation of a 21-gene expression assay in breast cancer

BACKGROUND Prior studies with the use of a prospective-retrospective design including archival tumor samples have shown that gene-expression assays provide clinically useful prognostic information. However, a prospectively conducted study in a uniformly treated population provides the highest level of evidence supporting the clinical validity and usefulness of a biomarker. METHODS We performed a prospective trial involving women with hormone-receptor-positive, human epidermal growth factor receptor type 2 (HER2)-negative, axillary node-negative breast cancer with tumors of 1.1 to 5.0 cm in the greatest dimension (or 0.6 to 1.0 cm in the greatest dimension and intermediate or high tumor grade) who met established guidelines for the consideration of adjuvant chemotherapy on the basis of clinicopathologic features. A reverse-transcriptase-polymerase-chain-reaction assay of 21 genes was performed on the paraffin-embedded tumor tissue, and the results were used to calculate a score indicating the risk of breast-cancer recurrence; patients were assigned to receive endocrine therapy without chemotherapy if they had a recurrence score of 0 to 10, indicating a very low risk of recurrence (on a scale of 0 to 100, with higher scores indicating a greater risk of recurrence). RESULTS Of the 10,253 eligible women enrolled, 1626 women (15.9%) who had a recurrence score of 0 to 10 were assigned to receive endocrine therapy alone without chemotherapy. At 5 years, in this patient population, the rate of invasive disease-free survival was 93.8% (95% confidence interval [CI], 92.4 to 94.9), the rate of freedom from recurrence of breast cancer at a distant site was 99.3% (95% CI, 98.7 to 99.6), the rate of freedom from recurrence of breast cancer at a distant or local-regional site was 98.7% (95% CI, 97.9 to 99.2), and the rate of overall survival was 98.0% (95% CI, 97.1 to 98.6). CONCLUSIONS Among patients with hormone-receptor-positive, HER2-negative, axillary node-negative breast cancer who met established guidelines for the recommendation of adjuvant chemotherapy on the basis of clinicopathologic features, those with tumors that had a favorable gene-expression profile had very low rates of recurrence at 5 years with endocrine therapy alone. (Funded by the National Cancer Institute and others; ClinicalTrials.gov number, NCT00310180.).

Genome-wide association study identifies variants in the MHC class I, IL10, and IL23R-IL12RB2 regions associated with Behcet's disease

Behçets disease is a genetically complex disease of unknown etiology characterized by recurrent inflammatory attacks affecting the orogenital mucosa, eyes and skin. We performed a genome-wide association study with 311,459 SNPs in 1,215 individuals with Behçets disease (cases) and 1,278 healthy controls from Turkey. We confirmed the known association of Behçets disease with HLA-B*51 and identified a second, independent association within the MHC Class I region. We also identified an association at IL10 (rs1518111, P = 1.88 × 10−8). Using a meta-analysis with an additional five cohorts from Turkey, the Middle East, Europe and Asia, comprising a total of 2,430 cases and 2,660 controls, we identified associations at IL10 (rs1518111, P = 3.54 × 10−18, odds ratio = 1.45, 95% CI 1.34–1.58) and the IL23R-IL12RB2 locus (rs924080, P = 6.69 × 10−9, OR = 1.28, 95% CI 1.18–1.39). The disease-associated IL10 variant (the rs1518111 A allele) was associated with diminished mRNA expression and low protein production.

Leptin Concentrations in Relation to Body Mass Index and the Tumor Necrosis Factor-α System in Humans

The expression of leptin, an adipocyte-derived protein whose circulating levels reflect energy stores, can be induced by tumor necrosis factor (TNF)alpha in rodents, but an association between the TNF alpha system and leptin levels has not been reported in humans. To evaluate the potential association between serum leptin and the TNF alpha system, we measured the levels of soluble TNF alpha-receptor (sTNF alpha-R55), which has been validated as a sensitive indicator of activation of the TNF alpha system. We studied two groups: 1) 82 young healthy normal controls and 2) 48 patients with noninsulin dependent diabetes mellitus (NIDDM) and 24 appropriately matched controls. By simple regression analysis in controls, there was a strong positive association between leptin and 3 parameters: body mass index, sTNF alpha-R55, and insulin levels. In a multiple regression analysis model, leptin remained significantly and strongly associated with body mass index, and the association of leptin with both insulin and sTNF alpha-R55, although weakened, remained significant. Patients with NIDDM had leptin concentrations similar to controls of similar weight. Importantly, serum levels of sTNF alpha-R55 were also positively and independently associated with leptin in this group of diabetic subjects and matched controls. These data are consistent with the hypothesis that the TNF alpha system plays a role in regulating leptin levels in humans. Further elucidation of a possible role of the TNF alpha system in leptin expression and circulating levels may have important implications for our understanding of obesity and cachexia in humans.

Diabetes, Metformin, and Breast Cancer in Postmenopausal Women

PURPOSE Emerging evidence suggests that metformin may reduce breast cancer incidence, but reports are mixed and few provide information on tumor characteristics. Therefore, we assessed associations among diabetes, metformin use, and breast cancer in postmenopausal women participating in Womens Health Initiative clinical trials. PATIENTS AND METHODS In all, 68,019 postmenopausal women, including 3,401 with diabetes at study entry, were observed over a mean of 11.8 years with 3,273 invasive breast cancers diagnosed. Diabetes incidence status was collected throughout follow-up, with medication information collected at baseline and years 1, 3, 6, and 9. Breast cancers were confirmed by review of central medical records and pathology reports. Cox proportional hazards regression, adjusted for breast cancer risk factors, compared breast cancer incidence in women with diabetes who were metformin users or nonusers with breast cancer incidence in women without diabetes. RESULTS Compared with that in women without diabetes, breast cancer incidence in women with diabetes differed by diabetes medication type (P = .04). Women with diabetes receiving medications other than metformin had a slightly higher incidence of breast cancer (hazard ratio [HR], 1.16; 95% CI, 0.93 to 1.45), and women with diabetes who were given metformin had lower breast cancer incidence (HR, 0.75; 95% CI, 0.57 to 0.99). The association was observed for cancers positive for both estrogen receptor and progesterone receptor and those that were negative for human epidermal growth factor receptor 2. CONCLUSION Metformin use in postmenopausal women with diabetes was associated with lower incidence of invasive breast cancer. These results can inform future studies evaluating metformin use in breast cancer management and prevention.

Dietary Fat and Carbohydrates Are Independently Associated With Circulating Insulin-Like Growth Factor 1 and Insulin-Like Growth Factor–Binding Protein 3 Concentrations in Healthy Adults

PURPOSE To evaluate and quantify the association between consumption of specific food groups/macronutrients and concentrations of serum insulin-like growth factor 1 (IGF-1) and insulin-like growth factor-binding protein 3 (IGFBP-3). SUBJECTS AND METHODS Data from a comprehensive food-frequency questionnaire administered to 115 healthy subjects were used to study cross-sectionally the relationship between nutritional factors and circulating IGF-1 and IGFBP-3 concentrations. Adjustment for the effect of total energy intake and a series of epidemiologic parameters (age, sex, height, body mass index, smoking, alcohol consumption, and coffee drinking) was implemented through multivariate linear regression. RESULTS We observed that serum levels of IGF-1 are positively associated with consumption of red meats, fats, and oils. In addition, serum levels of IGF-1 are independently and positively associated with energy intake from lipids and negatively associated with energy intake from carbohydrates. Finally, serum levels of IGFBP-3 are independently and negatively associated with energy intake from saturated fat. CONCLUSION Serum IGF-1 and/or IGFBP-3 concentrations are associated with red meat, carbohydrate intake, and fat intake and, thus, may mediate the effect of these dietary factors on the pathogenesis of several disease states. Additional studies are needed to further quantify these associations and elucidate the underlying mechanisms.

TGFBR1*6A and Cancer Risk: A Meta-Analysis of Seven Case-Control Studies

PURPOSE TGFBR1*6A is a hypomorphic polymorphic allele of the type I transforming growth factor beta receptor (TGFBR1). TGFBR1*6A is a candidate tumor susceptibility allele that has been associated with an increased incidence of various types of cancer. This study was undertaken to analyze all published case-control studies on TGFBR1*6A and cancer and determine whether TGFBR1*6A is associated with cancer. PATIENTS AND METHODS All published case-control studies assessing the germline frequency of TGFBR1*6A were included. Studies assessing TGFBR1*6A in tumors were excluded. The results of seven studies comprising 2,438 cases and 1,846 controls were pooled and analyzed. RESULTS Overall, TGFBR1*6A carriers have a 26% increased risk of cancer (odds ratio [OR], 1.26; 95% confidence interval [CI], 1.07 to 1.49). Cancer risk for TGFBR1*6A homozygotes (OR, 2.53; 95% CI, 1.39 to 4.61) is twice that of TGFBR1*6A heterozygotes (OR, 1.26; 95% CI, 1.04 to 1.51). Analysis of various types of tumors shows that TGFBR1*6A carriers are at increased risk of developing breast cancer (OR, 1.48; 95% CI, 1.11 to 1.96), hematological malignancies (OR, 1.70; 95% CI, 1.13 to 2.54), and ovarian cancer (OR, 1.53; 95% CI, 1.07 to 2.17). Carriers of TGFBR1*6A who are from the United States are at increased risk of colorectal cancer (OR, 1.38; 95% CI, 1.02 to 1.86). However, Southern European TGFBR1*6A carriers have no increased colorectal cancer risk. There is no association between TGFBR1*6A and bladder cancer. CONCLUSION TGFBR1*6A is emerging as a highfrequency, low-penetrance tumor susceptibility allele that predisposes to the development of breast, ovarian, and colorectal cancer, as well as hematologic malignancies.

HER2-positive breast cancer: current and future treatment strategies.

In the year 2006, breast cancer was estimated to affect >200 000 American women and cause nearly 56 000 deaths. Furthermore, breast cancer is the most common cancer diagnosed and second most common cause of cancer-related deaths in women. The current treatment armamentarium for breast cancer includes chemotherapy, endocrine therapy and biological therapy. Treatment has become more individualised based on characteristics of the tumour including overexpression of the human epidermal growth factor receptor (HER)-2. Between 20 and 30% of all breast cancers overexpress HER2, which means 40 000–60 000 patients will have this type of cancer.Previously, overexpression of HER2 was a negative prognostic and predictive risk factor for survival; however, with the advent of trastuzumab, patients’ prognosis is improving in all treatment settings. Much controversy exists in the use of trastuzumab, including (i) the sequence of adjuvant trastuzumab (concurrent with chemotherapy or sequential); (ii) the treatment duration (<1 year, 1 year or 2 years); and (iii) the treatment choice upon disease progression (whether to continue or not with trastuzumab and add another cytotoxic agent). Current trials are ongoing to help answer these questions.Furthermore, there has been interest in predicting which HER2-positive patients would require anthracycline therapy, and which could avoid anthra-cycline therapy and its toxicities. Novel therapeutics, such as lapatinib, an oral tyrosine kinase inhibitor, which blocks both the epidermal growth factor receptor and HER2 receptor has recently been approved by the US FDA. Whereas pertuzumab, a humanised monoclonal antibody, directed against heterodimerisation of HER2 and HER3 has entered phase II and III clinical trials.

Age, sex, and smoking are predictors of circulating insulin-like growth factor 1 and insulin-like growth factor-binding protein 3

PURPOSE Insulin-like growth factor (IGF-1) and its major binding protein (IGF-BP3) have recently been implicated in the pathogenesis of several malignancies. However, anthropometric and lifestyle predictors of these hormones have not been elucidated. Here we report the results of a cross-sectional study. SUBJECTS AND METHODS This cross-sectional study examines the relationship of a series of epidemiologic parameters (age, sex, height, body mass index, smoking, alcohol consumption, and coffee drinking) with IGF-1 and IGF-BP3 in a sample of 130 healthy adults. RESULTS We observed that serum levels of IGF-1 are higher, whereas levels of IGF-BP3 are lower, in men than in women. In addition, serum levels of IGF-1 are independently and negatively associated with age and positively associated with pack-year history of smoking. Finally, serum levels of IGF-BP3 are independently and negatively associated with the number of cigarettes smoked per day or pack-year history of smoking. CONCLUSION Age, sex, and smoking are independent predictors of IGF-1 and/or IGF-BP3. The influence of these epidemiologic variables on the pathogenesis of disease states associated with IGF-1 and IGF-BP3 warrants further exploration.

Variants of the adiponectin and adiponectin receptor 1 genes and breast cancer risk.

Breast cancer risk is higher among obese women and women with diabetes. Adiponectin is a protein exclusively secreted by adipose tissue, circulating levels of which have been associated with breast cancer risk. Whether genetic variants within the adiponectin pathway are associated with breast cancer risk is unknown. To explore the association of genetic variants of the adiponectin (ADIPOQ) and adiponectin receptor 1 (ADIPOR1) genes with breast cancer risk, we conducted a case control study of female patients with breast cancer and healthy female controls from New York City recruited between 1999 and 2004. We genotyped 733 hospital-based breast cancer cases and 839 controls for 10 haplotype-tagging single nucleotide polymorphisms (SNP) of ADIPOQ and ADIPOR1. Two ADIPOQ SNPs (rs2241766 and rs1501299), which have been associated with circulating levels of adiponectin, were associated with breast cancer risk [rs1501299*GG: odd ratios (OR), 1.80; 95% confidence interval (95% CI), 1.14-2.85; rs2241766*TG: OR, 0.61; 95% CI, 0.46-0.80]. One ADIPOR1 SNP (rs7539542), which modulates expression of adiponectin receptor 1 mRNA, was also associated with breast cancer risk (OR, 0.51; 95% CI, 0.28-0.92). Based on the known function of rs2241766 and rs1501299, we categorized individuals by adiponectin signaling status and found that, when compared with high signalers, intermediate signalers had a 4.16-fold increase in breast cancer risk (95% CI, 0.49-35.19), and low signalers had a 6.56-fold increase in breast cancer risk (95% CI, 0.78-54.89; P(trend) = 0.001). This is the first report of an association between functionally relevant variants of the adiponectin pathway and breast cancer risk. The results warrant further studies of the adiponectin pathway in breast cancer.

TGFBR1*6A and Cancer: A Meta-Analysis of 12 Case-Control Studies

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