Faculty Bibliography

INTRODUCTION: Rapamycin acts synergistically with platinum agents to induce apoptosis and inhibit proliferation in breast cancer cell lines. Combination of everolimus also known as RAD001 (oral mammalian target of rapamycin (mTOR) inhibitor) and carboplatin may have activity in metastatic triple-negative breast cancer (TNBC). METHODS: The primary objective of this study was to determine clinical benefit rate (CBR), that is (complete remission (CR) + partial remission (PR) + stable disease (SD) lasting >/=6 months) and the toxicity of everolimus/carboplatin in women with metastatic TNBC. Prior carboplatin was allowed. Treatment consisted of intravenous carboplatin area under the curve (AUC) 6 (later decreased to AUC 5 and subsequently to AUC 4) every 3 weeks with daily 5 mg everolimus. RESULTS: We enrolled 25 patients in this study. Median age was 58 years. There were one CR, six PRs, seven SDs and eight PDs (progression of disease). CBR was 36% (95% confidence interval (CI) 21.1 to 57.4%). One SD was achieved in a patient progressing on single agent carboplatin. The median progression free survival (PFS) was 3 months (95% CI 1.6 to 4.6 months) and overall survival (OS) was 16.6 months (95% CI 7.3 months to not reached). There were seven patients (28%) with >/= grade 3 thrombocytopenia; three (12%) with grade 3 neutropenia (no bleeding/febrile neutropenia) and one (4%) with grade 3 anemia. Greater hematological toxicity was seen in the first seven patients treated with carboplatin AUC5/6. After the amendment for starting dose of carboplatin to AUC 4, the regimen was well tolerated with only one out of 18 patients with grade 3 neutropenia and two patients with grade 3 thrombocytopenia. There was only one case of mucositis. CONCLUSION: Everolimus-carboplatin was efficacious in metastatic TNBC. Dose limiting hematological toxicity was observed when AUC5/6 of carboplatin was combined with everolimus. However, carboplatin AUC 4 was well tolerated in combination with everolimus with continuing responses. TRIAL REGISTRATIONS: ClinicalTrials.gov NCT01127763.

BACKGROUND: Young breast cancer (BC) patients less than 45 years old are at higher risk of dying from the disease when compared to their older counterparts. However, specific risk factors leading to this poorer outcome have not been identified. METHODS: One candidate is iron deficiency, as this is common in young women and a clinical feature of young age. In the present study, we used immuno-competent and immuno-deficient mouse xenograft models as well as hemoglobin as a marker of iron status in young BC patients to demonstrate whether host iron deficiency plays a pro-metastatic role. RESULTS: We showed that mice fed an iron-deficient diet had significantly higher tumor volumes and lung metastasis compared to those fed normal iron diets. Iron deficiency mainly altered Notch but not TGF-beta and Wnt signaling in the primary tumor, leading to the activation of epithelial mesenchymal transition (EMT). This was revealed by increased expression of Snai1 and decreased expression of E-cadherin. Importantly, correcting iron deficiency by iron therapy reduced primary tumor volume, lung metastasis, and reversed EMT markers in mice. Furthermore, we found that mild iron deficiency was significantly associated with lymph node invasion in young BC patients (p<0.002). CONCLUSIONS: Together, our finding indicates that host iron deficiency could be a contributor of poor prognosis in young BC patients.

Background: Epigenetic regulatory pathways are intensely studied for their involvement in breast tumorigenesis, however little is currently known about the genetic variation in epigenome components contributing to the risk and/or prognosis of breast cancer. In this study we have tested how the novel germline genetic signatures identified in epigenetic regulatory genes (ERGs) may potentially contribute to clinical prediction of breast cancer risk. Methods: We have genotyped 711 SNPs tagging 87 ERGs in 1985 breast cancer cases and 1609 controls, using Sequenom i-Plex. The samples were of white European origin with the fraction of Ashkenazi Jewish (AJ) ancestry (n=1642). The association of SNPs with breast cancer risk was assessed using logistic regression, adjusted by age, AJ status and estrogen-receptor (ER) status. The predictive ability of SNP signatures was tested by ROC curves using logistic regression fitting the SNP/clinical covariate models, and the area under the curve (AUC) was used to assess their utility in the classification of breast cancer risk. Results: We have identified the signature of 20 SNPs tagging 13 ERGs, significantly associated with breast cancer risk. The strongest association has been observed for RUNX1 (rs7280097, OR=0.83, CI 95%: 0.71-0.94, p=0.006) and PRDM16 (rs12135987, OR=1.22, CI 95%: 1.06-1.42, p=0.007). The inclusion of predictor variables (age, AJ status, ER status) and 20 associated SNPs in logistic regression ROC curve analysis yielded in best fitting model involving 10 SNPs tagging 8 ERGs with AUC of 0.723, compared to 0.660 with predictor variables alone (p=0.003). Conclusions: We have identified a signature of 20 SNPs in epigenetic regulatory genes (20-SNP-ERG) significantly associated with breast cancer risk. In addition, the incorporation of 10 SNPs from 20-SNP-ERG into risk prediction model increases the ability to classify breast cancer risk in addition to other clinical and demographic covariates. The results suggest the promising clinical potential!

BACKGROUND: Tamoxifen or raloxifen for 5 years reduces the risk of developing invasive breast cancer by 40%. To address safety concerns and seek enhanced efficacy, studies of new chemopreventive agents using mammographic density as a surrogate end point are attractive. PATIENTS AND METHODS: Postmenopausal women with risk factors for developing breast cancer were given letrozole 2.5 mg daily for one year, and mammographic density was the biomarker of breast cancer risk modification. It was assessed (blinded to the reader) at baseline, 6, and 12 months in 16 evaluable women among 20 enrolled. RESULTS: Eight patients exhibited decreased mammographic density at six months, and eleven at 12 months. Toxicities included joint aches not precluding continued treatment. CONCLUSION: This pilot study supports the use of letrozole for reducing breast cancer risk. In addition, it encourages prospective studies of serial changes in mammographic density as a biomarker of risk modification within a selected high-risk population.