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Purpose Expanded access programs (EAPs) allow patients with cancer who have unmet clinical needs to obtain access to pre-authorisation treatments. There is no standardised process or registry for implementing these programs nationally and real world data on their impact is lacking. We evaluated their prevalence and impact in a cancer centre.Methods Data relating to adult cancer patients treated via EAPs from 2011 to 2021 in three Cork university hospitals was collated. Descriptive statistics were employed to get an overview of the impact these programs currently have on cancer care provision.Results We identified 193 patients who accessed EAPs during the study period, availing of 33 separate drugs for a total of 50 different cancer indications. The prevalence of EAP usage was shown to have been trending upwards in recent years with a total of 189 programs being accessed throughout the period. Drugs provided were from a number of different anti-cancer drug classes, particularly targeted therapies (n = 18) and immune checkpoint inhibitors (n = 17). Cancers from a wide range of both solid and liquid tumour types were identified as having been treated with EAP drugs and patients treated were from across a broad spectrum of ages (26–82, SD:11.99).Conclusion EAPs have an increasing role in access to novel cancer therapies in our community and by extension nationally. Equity of EAP access would be facilitated by a national registry of available agents which we have now established. Assessment of their benefits and toxicities would be enhanced by the requirement for a real world data base as a condition of EAP approval.

PDF file - 395KB, Figure S1. Pre-surgery plasma ddPCR analysis for PIK3CA mutations. Figure S2. Positive and negative controls for droplet thresholds and counts. Figure S3. Lower Limit of Detection for PIK3CA Exon 9. Supplementary Table S1: Primers used to amplify and sequence FFPE specimens. Supplementary Table S2: Primers and probes used for ddPCR on FFPE samples. Supplementary Table S3: Primers and probes for ddPCR of plasma DNA. Supplementary Table S4: Fractional abundance and 95% confidence intervals of positive ptDNA samples.

Purpose: Detecting circulating plasma tumor DNA (ptDNA) in patients with early-stage cancer has the potential to change how oncologists recommend systemic therapies for solid tumors after surgery. Droplet digital polymerase chain reaction (ddPCR) is a novel sensitive and specific platform for mutation detection.Experimental Design: In this prospective study, primary breast tumors and matched pre- and postsurgery blood samples were collected from patients with early-stage breast cancer (n = 29). Tumors (n = 30) were analyzed by Sanger sequencing for common PIK3CA mutations, and DNA from these tumors and matched plasma were then analyzed for PIK3CA mutations using ddPCR.Results: Sequencing of tumors identified seven PIK3CA exon 20 mutations (H1047R) and three exon 9 mutations (E545K). Analysis of tumors by ddPCR confirmed these mutations and identified five additional mutations. Presurgery plasma samples (n = 29) were then analyzed for PIK3CA mutations using ddPCR. Of the 15 PIK3CA mutations detected in tumors by ddPCR, 14 of the corresponding mutations were detected in presurgical ptDNA, whereas no mutations were found in plasma from patients with PIK3CA wild-type tumors (sensitivity 93.3%, specificity 100%). Ten patients with mutation-positive ptDNA presurgery had ddPCR analysis of postsurgery plasma, with five patients having detectable ptDNA postsurgery.Conclusions: This prospective study demonstrates accurate mutation detection in tumor tissues using ddPCR, and that ptDNA can be detected in blood before and after surgery in patients with early-stage breast cancer. Future studies can now address whether ptDNA detected after surgery identifies patients at risk for recurrence, which could guide chemotherapy decisions for individual patients. Clin Cancer Res; 20(10); 2643–50. ©2014 AACR.

PDF file - 1480K, Figure S1. Double knock in clones have single mutant PIK3CA alleles and equivalent expression of mutant and wild type PIK3CA and form aberrant structures in 3D culture. Figure S2. DKI xenografts retain the same number of KRAS and PIK3CA alleles. Figure S3. Knock out of mutant PIK3CA affects tumorigenicity in nude mouse xenograft assays. Figure S4. DKI cell lines show phosphorylation of Akt and Erk in physiologic but not supra-physiologic concentrations of EGF. Figure S5. DKI cells have increased phosphorylation of S6 ribosomal protein but not 4E-BP1. Figure S6. DKI cells are sensitive to the MEK inhibitor U0126 but not to rapamycin and show differential effects on phosphorylation of Akt, Erk, p70S6K and p90RSK. Figure S7. Transgene expression of mutant PIK3CA cDNA with and without RBD mutations in MCF- 10A and KRAS G12V knock in cell lines. Figure S8. Pdk1 activity is increased in DKI cells.

This study evaluates the safety, efficacy, and biomarkers of response to cabozantinib, a multikinase inhibitor, in patients with metastatic triple‐negative breast cancer (mTNBC). Cabozantinib showed encouraging safety and efficacy signals but did not meet the prespecified primary endpoint in pretreated mTNBC. Exploratory analyses of circulating biomarkers showed that cabozantinib induces systemic changes consistent with activation of the immune system and antiangiogenic activity, and soluble MET should be further evaluated as a potential biomarker of response., Currently, no targeted therapies are available for metastatic triplenegative breast cancer (mTNBC). We evaluated the safety, efficacy, and biomarkers of response to cabozantinib, a multikinase inhibitor, in patients with mTNBC. We conducted a single arm phase II and biomarker study that enrolled patients with measurable mTNBC. Patients received cabozantinib (60 mg daily) on a 3‐week cycle and were restaged after 6 weeks and then every 9 weeks. The primary endpoint was objective response rate. Predefined secondary endpoints included progression‐free survival (PFS), toxicity, and tissue and blood circulating cell and protein biomarkers. Of 35 patients who initiated protocol therapy, 3 (9% [95% confidence interval (CI): 2, 26]) achieved a partial response (PR). Nine patients achieved stable disease (SD) for at least 15 weeks, and thus the clinical benefit rate (PR+SD) was 34% [95% CI: 19, 52]. Median PFS was 2.0 months [95% CI: 1.3, 3.3]. The most common toxicities were fatigue, diarrhea, mucositis, and palmar‐plantar erythrodysesthesia. There were no grade 4 toxicities, but 12 patients (34%) required dose reduction. Two patients had TNBCs with MET amplification. During cabozantinib therapy, there were significant and durable increases in plasma placental growth factor, vascular endothelial growth factor (VEGF), VEGF‐D, stromal cell‐derived factor 1a, and carbonic anhydrase IX, and circulating CD3 + cells and CD8 + T lymphocytes, and decreases in plasma soluble VEGF receptor 2 and CD14+ monocytes (all p

Background: Acquiring resistance to endocrine therapy is common in metastatic hormone-receptor-positive breast cancer (MBC). These patients most often transition either to next-line endocrine therapy or to systemic chemotherapy. However, withdrawal of endocrine therapy and observation as is selectively practiced in prostate cancer is another potential strategy for breast cancer patients. Methods: A prospective, single-arm phase II trial of aromatase inhibitor (AI) withdrawal was performed in women with MBC, who had disease progression on AI therapy. The primary objective was to estimate the clinical benefit rate (defined as complete or partial response, or stable disease for at least 24 weeks, by RECIST criteria). Participants were monitored clinically and radiographically off all therapy at 8, 16 and 24 weeks after treatment and every 12 weeks thereafter until disease progression. Results: Twenty-four patients (of 40 intended) were enrolled when the study was closed due to slow accrual. Clinical benefit rate overall was 46% (95% CI 26% to 67%). Median progression-free survival from time of AI withdrawal was 4 months. Two patients have remained progression free, off all treatment, for over 60 months. Conclusions: Despite suboptimal patient accrual, our results suggest that selected patients with metastatic breast cancer progressing on AI therapy can experience disease stabilisation and a period of observation after AI withdrawal. A randomised phase II trial is planned.

Purpose: Detecting circulating plasma tumor DNA (ptDNA) in patients with early-stage cancer has the potential to change how oncologists recommend systemic therapies for solid tumors after surgery. Droplet digital polymerase chain reaction (ddPCR) is a novel sensitive and specific platform for mutation detection. Experimental Design: In this prospective study, primary breast tumors and matched pre- and postsurgery blood samples were collected from patients with early-stage breast cancer (n = 29). Tumors (n = 30) were analyzed by Sanger sequencing for common PIK3CA mutations, and DNA from these tumors and matched plasma were then analyzed for PIK3CA mutations using ddPCR. Results: Sequencing of tumors identified seven PIK3CA exon 20 mutations (H1047R) and three exon 9 mutations (E545K). Analysis of tumors by ddPCR confirmed these mutations and identified five additional mutations. Presurgery plasma samples (n = 29) were then analyzed for PIK3CA mutations using ddPCR. Of the 15 PIK3CA mutations detected in tumors by ddPCR, 14 of the corresponding mutations were detected in presurgical ptDNA, whereas no mutations were found in plasma from patients with PIK3CA wild-type tumors (sensitivity 93.3%, specificity 100%). Ten patients with mutation-positive ptDNA presurgery had ddPCR analysis of postsurgery plasma, with five patients having detectable ptDNA postsurgery. Conclusions: This prospective study demonstrates accurate mutation detection in tumor tissues using ddPCR, and that ptDNA can be detected in blood before and after surgery in patients with early-stage breast cancer. Future studies can now address whether ptDNA detected after surgery identifies patients at risk for recurrence, which could guide chemotherapy decisions for individual patients. Clin Cancer Res; 20(10); 2643–50. ©2014 AACR.

Circulating Tumor cells (CTCs) represent tumor cells in the blood stream dislodged from the primary tumor. The presence of CTCs in the bloodstream provides a unique opportunity to sample cancer tissue by means of a relatively less-invasive “liquid biopsy.” Over the past decade, there has been a tremendous increase in the amount of research examining the potential clinical utility of CTCs in the management of cancer. A number of techniques to refine the sensitivity and range of CTC assays are also in development. In this article, we review the recent developments in the current and potential clinical applications of CTCs in breast cancer. CTC enumeration already has an established role as a prognostic biomarker in metastatic breast cancer, while molecular characterization of CTCs can serve as a potential predictive biomarker for therapy selection, pharmacodynamic evaluation, and identification of novel actionable targets for novel therapies. The role of CTCs in breast cancer screening and detection of recurrence is currently limited. Further development in techniques will be pivotal in enhancing the broad applicability of CTCs and advancing the field of personalized breast cancer therapy.

Purpose: Agents that target the epigenome show activity in breast cancer models. In preclinical studies, the histone deacetylase inhibitor vorinostat induces cell-cycle arrest, apoptosis, and differentiation. We evaluated biomarker modulation in breast cancer tissues obtained from women with newly diagnosed invasive disease who received vorinostat and those who did not. Experimental Design: Tumor specimens were collected from 25 women who received up to 6 doses of oral vorinostat 300 mg twice daily and from 25 untreated controls in a nonrandomized study. Candidate gene expression was analyzed by reverse transcription PCR (RT-PCR) using the Oncotype DX 21-gene assay, and by immunohistochemistry for Ki-67 and cleaved caspase-3. Matched samples from treated women were analyzed for gene methylation by quantitative multiplex methylation-specific PCR (QM-MSP). Wilcoxon nonparametric tests were used to compare changes in quantitative gene expression levels pre- and post-vorinostat with changes in expression in untreated controls, and changes in gene methylation between pre- and post-vorinostat samples. Results: Vorinostat was well tolerated and there were no study-related delays in treatment. Compared with untreated controls, there were statistically significant decreases in the expression of proliferation-associated genes Ki-67 (P = 0.003), STK15 (P = 0.005), and Cyclin B1 (P = 0.03) following vorinostat, but not in other genes by the Oncotype DX assay, or in expression of Ki-67 or cleaved caspase-3 by immunohistochemistry. Changes in methylation were not observed. Conclusions: Short-term vorinostat administration is associated with a significant decrease in expression of proliferation-associated genes in untreated breast cancers. This demonstration of biologic activity supports investigation of vorinostat in combination with other agents for the management of breast cancer. Clin Cancer Res; 19(14); 4008–16. ©2013 AACR.

Non-communicable diseases, including cancer, are overtaking infectious disease as the leading health-care threat in middle-income and low-income countries. Latin American and Caribbean countries are struggling to respond to increasing morbidity and death from advanced disease. Health ministries and health-care systems in these countries face many challenges caring for patients with advanced cancer: inadequate funding; inequitable distribution of resources and services; inadequate numbers, training, and distribution of health-care personnel and equipment; lack of adequate care for many populations based on socioeconomic, geographic, ethnic, and other factors; and current systems geared toward the needs of wealthy, urban minorities at a cost to the entire population. This burgeoning cancer problem threatens to cause widespread suffering and economic peril to the countries of Latin America. Prompt and deliberate actions must be taken to avoid this scenario. Increasing efforts towards prevention of cancer and avoidance of advanced, stage IV disease will reduce suffering and mortality and will make overall cancer care more affordable. We hope the findings of our Commission and our recommendations will inspire Latin American stakeholders to redouble their efforts to address this increasing cancer burden and to prevent it from worsening and threatening their societies.

Lessons Learned Despite evidence for a role for prolactin signaling in breast and prostate tumorigenesis, a prolactin receptor-binding monoclonal antibody has not produced clinical efficacy. Increased serum prolactin levels may be a biomarker for prolactin receptor inhibition. Results from the pharmacokinetic and pharmacodynamics (PD) studies suggest that inappropriately long dosing intervals and insufficient exposure to LFA102 may have resulted in lack of antitumor efficacy. Based on preclinical data, combination therapy of LFA102 with those novel agents targeting hormonal pathways in metastatic castration-resistant prostate cancer and metastatic breast cancer is promising. Given the PD evidence of prolactin receptor blockade by LFA102, this drug has the potential to be used in conditions such as hyperprolactinemia that are associated with high prolactin levels. Background. Prolactin receptor (PRLR) signaling is implicated in breast and prostate cancer. LFA102, a humanized monoclonal antibody (mAb) that binds to and inhibits the PRLR, has exhibited promising preclinical antitumor activity. Methods. Patients with PRLR-positive metastatic breast cancer (MBC) or metastatic castration-resistant prostate cancer (mCRPC) received doses of LFA102 at 3–60 mg/kg intravenously once every 4 weeks. Objectives were to determine the maximum tolerated dose (MTD) and/or recommended dose for expansion (RDE) to investigate the safety/tolerability of LFA102 and to assess pharmacokinetics (PK), pharmacodynamics (PD), and antitumor activity. Results. A total of 73 patients were enrolled at 5 dose levels. The MTD was not reached because of lack of dose-limiting toxicities. The RDE was established at 60 mg/kg based on PK and PD analysis and safety data. The most common all-cause adverse events (AEs) were fatigue (44%) and nausea (33%) regardless of relationship. Grade 3/4 AEs reported to be related to LFA102 occurred in 4% of patients. LFA102 exposure increased approximately dose proportionally across the doses tested. Serum prolactin levels increased in response to LFA102 administration, suggesting its potential as a biomarker for PRLR inhibition. No antitumor activity was detected. Conclusion. Treatment with LFA102 was safe and well tolerated, but did not show antitumor activity as monotherapy at the doses tested.

Background: Her2/neu overexpression is an independent adverse prognostic factor present in approximately 25% of invasive breast cancers. HER2−overexpressing breast cancer is particularly common in younger patients and therefore poses a significant public health burden. Anti-Her2/neu adjuvant trastuzumab significantly reduces the risk of recurrence as well as improves survival. In view of the serious potential ramifications of not receiving anti-Her2/neu therapy when appropriate, we undertook this international project to determine clinical access to Her2/neu testing and treatment patterns for women with HER2/neu-positive early breast cancer. Methods: A web-based survey was sent to 386 physicians from 33 countries who participated in the “TEACH” trial, a double blind placebo-controlled phase III study of a novel anti-Her2/neu therapy, lapatinib, in women with primary Her2/neu-positive breast cancer. The survey contained 27 questions addressing physician and patient demographics, access to Her-2/Neu testing in everyday clinical practice, and anti-Her2/neu treatment options in a variety of clinical scenarios. Results: One hundred and fifty one participants (39%) from 28 countries answered the survey. Ninety eight percent of the participants reported having Her2/neu tumor expression routinely measured for clinical practice in their institutions by immunohistochemistry (83%), FISH (78%) and other methods (17%). Among Asian physicians, 18% did not have routine testing available and sent primary tumors for central testing for TEACH eligibility. Forty eight percent of physicians surveyed reported instances when they had recommended adjuvant Her2-directed therapy to a patient who eventually did not receive it. The proportion of physicians from developing countries that reported patients not receiving therapy was higher than those from developed countries (68% vs. 38%, respectively). The main reason for not receiving trastuzumab was cost in developing countries, while in more developed countries patient refusal and co-morbidities were the main reasons. Discussion: This survey reflects availability of HER2 breast tumor testing and anti-Her2/neu therapy among physicians from 28 countries worldwide who participated in an anti-Her2/neu therapy clinical trial of a free anti-Her2/neu therapy. These results indicate that a high proportion of women with Her2/neu-overexpressing breast cancer may not receive standard anti-Her2/neu adjuvant therapy especially in developing countries, the barrier to treatment being cost of therapy. We are extending our access to care survey project to a more unselected diverse group of physicians in developing countries. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-12-26.

Background: Breast cancer is the most common form of cancer and the leading cause of cancer death in women worldwide. More than 55% of breast cancer deaths occur in low and middle income countries. Although incidence rates for breast cancer are lower in developing countries, mortality rates are higher. This phenomenon has been attributed to limited access to care for breast cancer patients, including screening and early diagnosis as well as primary surgical, radiation and systemic therapies. Similar to trends in other poor and middle income countries, breast cancer mortality in Mexico is rising. The goal of this survey of physicians caring for patients with breast cancer in Mexico is to obtain information about current treatment patterns of newly diagnosed patients and to describe their clinical characteristics. Methods: A web-based closed survey has been sent to 854 physicians providing care to newly diagnosed breast cancer patients across Mexico, including medical oncologists and breast cancer surgeons. The survey instrument contains 35 questions assessing demographic data, access to diagnosis and treatment in a variety of clinical patient scenarios. The responses will be anonymous and entered automatically into a secure database for analysis. Fisher exact test will be used for the frequency analysis. Chi-squared statistics and Kendall correlation will be used for nominal and ordinal variables respectively. Results: The results will be presented at the 2011 San Antonio Breast Cancer Symposium. Conclusions: The results of this survey will highlight potential disparities in care received by breast cancer patients across the full geographic and socioeconomic spectrum of Mexico in order to highlight the need for uniform, quality based approaches for the diagnosis and treatment of breast cancer patients in Mexico, and will serve as an example of how one middle income country faces challenges and unmet medical needs regarding access to care of women with breast cancer. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-11-12.

Presentation of the Case A 51-year-old woman presents with an abnormal screening mammogram. Core biopsy shows an invasive ductal cancer that stains strongly for estrogen receptor (ER) and progesterone receptor (PR) and does not overexpress human epidermal growth factor receptor 2. She underwent a partial mastectomy and sentinel node biopsy. The invasive tumor measured 2.1 cm in greatest diameter and was grade 1. There was a 0.4 cm metastatic deposit in one of two sentinel lymph nodes (pT1cN1/stage IIA). There was no tumor within 0.2 cm of all margins and no lymphatic or vascular invasion noted. She was evaluated in the breast multidisciplinary clinic by a medical, surgical, and radiation oncologist. The question for our colleagues is what is the optimal adjuvant therapy for this woman and, more specifically, is chemotherapy necessary?

The selective estrogen receptor modulator tamoxifen has been used for more than three decades for the treatment, and more recently prevention, of breast cancer in women of all ages. The conversion of tamoxifen to active metabolites involves several cytochrome P450 (CYP) enzymes. CYP2D6 is the key enzyme responsible for the conversion of N-desmethyl tamoxifen to endoxifen. Single nucleotide polymorphisms in the CYP2D6 gene are not uncommon, and some alleles code for enzymes with reduced, null, or increased activity. Multiple studies suggest that women who carry one or two variant CYP2D6 alleles that encode enzymes with null or reduced activity may have an inferior breast cancer outcome when treated with tamoxifen in the adjuvant setting compared to women carrying two alleles encoding an enzyme with normal activity. Unfortunately, the data are not uniformly concordant, and definitive evidence that would change routine clinical practice is not yet available. CYP2D6 activity can also be reduced by concomitant use of drugs that inhibit the enzyme, including antidepressants used for psychiatric conditions or to relieve hot flashes, and these should be avoided in tamoxifen users whenever possible. Emerging data suggest that host factors may also predict interpatient variability in response to aromatase inhibitors.

A high frequency of somatic mutations has been found in breast cancers within the gene encoding the catalytic p110α subunit of PI3K, PIK3CA. Using isogenic human breast epithelial cells, we have previously demonstrated that oncogenic PIK3CA "hotspot" mutations predict for response to the toxic effects of lithium. However, other somatic genetic alterations occur within this pathway in breast cancers, and it is possible that these changes may also predict for lithium sensitivity. We overexpressed the epidermal growth factor receptor (EGFR) into the non-tumorigenic human breast epithelial cell line MCF-10A, and compared these cells to isogenic cell lines previously created via somatic cell gene targeting to model Pten loss, PIK3CA mutations, and the invariant AKT1 mutation, E17K. EGFR overexpressing clones were capable of cellular proliferation in the absence of EGF and were sensitive to lithium similar to the results previously seen with cells harboring PIK3CA mutations. In contrast, AKT1 E17K cells and PTEN -/- cells displayed resistance or partial sensitivity to lithium, respectively. Western blot analysis demonstrated that lithium sensitivity correlated with significant decreases in both PI3K and MAPK signaling that were observed only in EGFR overexpressing and mutant PIK3CA cell lines. These studies demonstrate that EGFR overexpression and PIK3CA mutations are predictors of response to lithium, whereas Pten loss and AKT1 E17K mutations do not predict for lithium sensitivity. Our findings may have important implications for the use of these genetic lesions in breast cancer patients as predictive markers of response to emerging PI3K pathway inhibitors.

An oncogenic mutation (G49A:E17K) in the AKT1 gene has been described recently in human breast, colon, and ovarian cancers. The low frequency of this mutation and perhaps other selective pressures have prevented the isolation of human cancer cell lines that harbor this mutation thereby limiting functional analysis. Here, we create a physiologic in vitro model to study the effects of this mutation by using somatic cell gene targeting using the nontumorigenic human breast epithelial cell line, MCF10A. Surprisingly, knock in of E17K into the AKT1 gene had minimal phenotypic consequences and importantly, did not recapitulate the biochemical and growth characteristics seen with somatic cell knock in of PIK3CA hotspot mutations. These results suggest that mutations in critical genes within the PI3-kinase (PI3K) pathway are not functionally equivalent, and that other cooperative genetic events may be necessary to achieve oncogenic PI3K pathway activation in cancers that contain the AKT1 E17K mutation.

Evaluation of: Gnant M, Mlineritsch B, Schippinger W et al. Endocrine therapy plus zoledronic acid in premenopausal breast cancer. N. Engl. J. Med. 360(7), 679–691 (2009)Current expert guidelines support tamoxifen alone or tamoxifen plus ovarian suppression as adjuvant endocrine therapy for premenopausal women with hormone receptor-positive breast cancer. Aromatase inhibitors have succeeded tamoxifen as the endocrine manipulation of choice in the treatment of postmenopausal patients. However, their use as monotherapy has traditionally been contraindicated in premenopausal women because the suppression of peripheral aromatase results in reduced feedback to the hypothalamus, and an increase in ovarian stimulation. The Austrian Breast and Colorectal Cancer Study Group trial 12 randomized premenopausal women with endocrine-responsive early breast cancer receiving the luteinizing hormone-releasing hormone agonist goserelin to tamoxifen or anastrozole without finding a significant efficacy advantage for either ...

The phosphatidylinositol 3-kinase subunit PIK3CA is frequently mutated in human cancers. Here we used gene targeting to “knock in” PIK3CA mutations into human breast epithelial cells to identify new therapeutic targets associated with oncogenic PIK3CA. Mutant PIK3CA knockin cells were capable of epidermal growth factor and mTOR-independent cell proliferation that was associated with AKT, ERK, and GSK3β phosphorylation. Paradoxically, the GSK3β inhibitors lithium chloride and SB216763 selectively decreased the proliferation of human breast and colorectal cancer cell lines with oncogenic PIK3CA mutations and led to a decrease in the GSK3β target gene CYCLIN D1 . Oral treatment with lithium preferentially inhibited the growth of nude mouse xenografts of HCT-116 colon cancer cells with mutant PIK3CA compared with isogenic HCT-116 knockout cells containing only wild-type PIK3CA . Our findings suggest GSK3β is an important effector of mutant PIK3CA , and that lithium, an FDA-approved therapy for bipolar disorders, has selective antineoplastic properties against cancers that harbor these mutations.

Many women with hormone receptor-positive breast cancer will receive tamoxifen at some point in their treatment course. Tamoxifen is biotransformed to the potent antiestrogen endoxifen almost exclusively through the cytochrome P450 (CYP) 2D6 isoform. Although prospective data are lacking, the balance of evidence available currently suggests that a single nucleotide polymorphism in the CYP2D6 gene, particularly the presence of 2 null alleles, predicts for reduced tamoxifen metabolism and possibly poorer outcome than expected in patients with a wild-type genotype. Studies evaluating the impact of genetic polymorphisms that result in CYP2D6 with reduced or no activity on long-term outcome have been mostly retrospective and conducted on archival tissues or those obtained previously in prospective studies of tamoxifen. Until data are available from retrospective examinations of the large prospective trials already conducted, or adequately powered prospective analyses, transforming this information into guidelines for individual patients remains challenging. The authors do not currently recommend routine testing for CYP2D6 genotype for making clinical decisions regarding tamoxifen. Use of concomitant strong or intermediate inhibitors of CYP2D6 should be avoided when alternate medications are available. Ongoing research is directed toward identifying other polymorphisms that may influence the efficacy and safety of tamoxifen, other hormonal agents, and chemotherapies used to treat breast cancer. The hope is that in the future, not only tumor-associated factors but also germ-line host genetics can be used to determine whether a woman should receive treatment, and with which specific agents, to prevent breast cancer recurrence or death or avoid drug-related toxicities.

Paraneoplastic neurological disorders are a well recognized complication of malignancy. A case report to expand the currently described clinical manifestations of type 1 antineuronal antibody (ANNA-1)-associated paraneoplastic encephalomyelitis to include coma. We present an unusual case of fluctuating coma and rapid fulminant progression to acute respiratory failure from central alveolar hypoventilation caused by ANNA-1 paraneoplastic encephalomyelitis associated with small-cell lung carcinoma. Paraneoplastic infiltration of the brainstem and cerebellum, including respiratory and arousal centers, was documented on autopsy. Paraneoplastic encephalomyelitis should be considered as a possible cause of coma and central alveolar hypoventilation.

The selective pressures leading to cancers with mutations in both KRAS and PIK3CA are unclear. Here, we show that somatic cell knockin of both KRAS G12V and oncogenic PIK3CA mutations in human breast epithelial cells results in cooperative activation of the phosphoinositide 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) pathways in vitro, and leads to tumor formation in immunocompromised mice. Xenografts from double-knockin cells retain single copies of mutant KRAS and PIK3CA, suggesting that tumor formation does not require increased copy number of either oncogene, and these results were also observed in human colorectal cancer specimens. Mechanistically, the cooperativity between mutant KRAS and PIK3CA is mediated in part by Ras/p110α binding, as inactivating point mutations within the Ras-binding domain of PIK3CA significantly abates pathway signaling. In addition, Pdk1 activation of the downstream effector p90RSK is also increased by the combined presence of mutant KRAS and PIK3CA. These results provide new insights into mutant KRAS function and its role in carcinogenesis. Cancer Res; 73(11); 3248–61. ©2013 AACR.

Early hormone-receptor-positive breast cancer is a chronic relapsing disease that can remain clinically silent for many years. The NCIC-CTG MA.17/BIG 1–97 trial randomized disease-free early breast cancer patients who had received five years of adjuvant tamoxifen to either letrozole or placebo and was the first to demonstrate a benefit with extended endocrine therapy. MA.17/BIG 1–97 was stopped at the first interim analysis because disease free survival was strongly prolonged in the letrozole arm. Subsequent subset analyses and longer follow up have shown that this therapy improved survival across all groups, particularly among women with node-positive disease and those that were pre-menopausal at time of study enrolment. The MA.17/BIG 1–97 study should be considered a paradigm for extended adjuvant endocrine therapy in hormone-receptor-positive early breast cancer.

Purpose: We sought to evaluate the feasibility of detecting PIK3CA mutations in circulating tumor DNA (ctDNA) from plasma of patients with metastatic breast cancer using a novel technique called BEAMing. Experimental Design: In a retrospective analysis, 49 tumor and temporally matched plasma samples from patients with breast cancer were screened for PIK3CA mutations by BEAMing. We then prospectively screened the ctDNA of 60 patients with metastatic breast cancer for PIK3CA mutations by BEAMing and compared the findings with results obtained by screening corresponding archival tumor tissue DNA using both sequencing and BEAMing. Results: The overall frequency of PIK3CA mutations by BEAMing was similar in both patient cohorts (29% and 28.3%, respectively). In the retrospective cohort, the concordance of PIK3CA mutation status by BEAMing between formalin-fixed, paraffin-embedded (FFPE) samples and ctDNA from temporally matched plasma was 100% (34 of 34). In the prospective cohort, the concordance rate among 51 evaluable cases was 72.5% between BEAMing of ctDNA and sequencing of archival tumor tissue DNA. When the same archival tissue DNA was screened by both sequencing and BEAMing for PIK3CA mutations (n = 41 tissue samples), there was 100% concordance in the obtained results. Conclusions: Analysis of plasma-derived ctDNA for the detection of PIK3CA mutations in patients with metastatic breast cancer is feasible. Our results suggest that PIK3CA mutational status can change upon disease recurrence, emphasizing the importance of reassessing PIK3CA status on contemporary (not archival) biospecimens. These results have implications for the development of predictive biomarkers of response to targeted therapies. Clin Cancer Res; 18(12); 3462–9. ©2012 AACR.

Purpose: Erlotinib, an orally active selective inhibitor of the epidermal growth factor receptor (EGFR) tyrosine kinase, has synergistic activity with radiation and with cisplatin. The EGFR is overexpressed in the majority of head and neck cancers. The primary objective of this phase I study was to determine the maximum-tolerated dose (MTD) of erlotinib in combination with low-dose daily cisplatin and radiotherapy. We also sought evidence of biologic activity of erlotinib alone using serial 18-FDG positron emission tomography (PET) imaging. Experimental Design: Oral erlotinib was taken daily starting with a 14-day run-in and continued until radiation therapy (RT) was completed. Low-dose daily cisplatin, 6 mg/m2 i.v. was given concurrently with standard fractionation RT to a total dose of 66 to 70 Gy. Dose escalation followed a modified Fibonacci dose escalation design. Results: Twenty-two patients were enrolled and 18 patients received therapy on protocol. MTD of the combination of erlotinib, cisplatin, and RT was not reached. The recommended phase II dose of erlotinib is 150 mg per day in combination with cisplatin and RT, the highest dose of erlotinib evaluated in this study. 18F-FDG PET showed evidence for metabolic response to single-agent erlotinib. Per PERCIST criteria, the overall metabolic response rate at day 14 was 38.8% (95% CI: 17.3–64.3). On completion of concurrent chemoradiotherapy, overall response rate derived from tumor measurements based on imaging studies was 83% for all dose levels combined. Conclusions: Erlotinib in combination with low-dose daily cisplatin and RT is well tolerated and shows evidence of clinical efficacy. The combination should be evaluated further. Clin Cancer Res; 18(6); 1735–42. ©2012 AACR.

Bone-modifying therapy is a primary research interest in breast cancer. Several features contribute to the importance of the bone environment in the management of breast cancer. Firstly, bone metastases represent the most common site of breast cancer metastases and secondly, the emergence of cancer treatment-induced bone loss (CTIBL) among breast cancer survivors and patients is of increasing concern. Furthermore, concordant with the "seed and soil" theory, agents that alter the bone microenvironment may even prevent tumor cell seeding in bone and limit cancer growth.Medical databases and conference proceedings were searched to identify articles, abstracts and clinical trials that have or are investigating denosumab and bisphosphonates in cancer therapy. Our search included a predefined focus on bone-modifying therapies in early and advanced breast cancer.Bisphosphonates (BPs) have an established role both in the prevention and treatment of CTIBL and have been studied in the adjuvant setting for early breast cancer (EBC). Denosumab is a monoclonal antibody directed against RANK ligand and thereby inhibits osteoclastogenesis and bone resportion. It is the newest agent approved for the treatment of postmenopausal osteoporosis and the prevention of skeletal-related events (SRE) in cancer patients with solid tumors and bone metastases. Denosumab has a favorable toxicity profile in comparison to BPs and has the potential to improve cancer outcomes.This review examines the existing role of denosumab in the treatment of bone complications of breast cancer and its potential role as adjuvant therapy.

Observational studies have demonstrated a decreased incidence of cancers among users of HMG CoA reductase inhibitors (statins) and a reduced risk of recurrence among statin users diagnosed with early stage breast cancer. We initiated a prospective study to identify potential biomarkers of simvastatin chemopreventive activity that can be validated in future trials. The contralateral breast of women with a previous history of breast cancer was used as a high-risk model. Eligible women who had completed all planned treatment of a prior stage 0–III breast cancer received simvastatin 40 mg orally daily for 24–28 weeks. At baseline and end-of-study, we measured circulating concentrations of high-sensitivity C-reactive protein (hsCRP), estrogens, and fasting lipids; breast density on contralateral breast mammogram; and quality of life by Rand Short Form 36-Item health survey. Fifty women were enrolled with a median age of 53 years. Total cholesterol, LDL cholesterol, triglyceride, and hsCRP fell significantly during the study (P values < 0.001

Biallelic inactivation of cancer susceptibility gene BRCA1 leads to breast and ovarian carcinogenesis. Paradoxically, BRCA1 deficiency in mice results in early embryonic lethality, and similarly, lack of BRCA1 in human cells is thought to result in cellular lethality in view of BRCA1 's essential function. To survive homozygous BRCA1 inactivation during tumorigenesis, precancerous cells must accumulate additional genetic alterations, such as p53 mutations, but this requirement for an extra genetic “hit” contradicts the two-hit theory for the accelerated carcinogenesis associated with familial cancer syndromes. Here, we show that heterozygous BRCA1 inactivation results in genomic instability in nontumorigenic human breast epithelial cells in vitro and in vivo. Using somatic cell gene targeting, we demonstrated that a heterozygous BRCA1 185delAG mutation confers impaired homology-mediated DNA repair and hypersensitivity to genotoxic stress. Heterozygous mutant BRCA1 cell clones also showed a higher degree of gene copy number loss and loss of heterozygosity in SNP array analyses. In BRCA1 heterozygous clones and nontumorigenic breast epithelial tissues from BRCA mutation carriers, FISH revealed elevated genomic instability when compared with their respective controls. Thus, BRCA1 haploinsufficiency may accelerate hereditary breast carcinogenesis by facilitating additional genetic alterations.

In recent years the description of well-defined molecular subtypes of breast cancer, together with the identification of the driving genetic alterations and signaling pathways, has led to the clinical development of a number of successful molecular targeted agents. This is best exemplified in the subset of HER2-amplified breast cancers, in which an increasing number of active agents are changing the natural history of this aggressive disease. Other targets are under exploration, and the clinical development of these agents will require a change from the current large, randomized trials in unselected patient populations to smaller trials in groups with a molecularly defined tumor type. In addition, combinatorial approaches that act on the secondary mutations and/or compensatory pathways in resistant tumors may markedly improve on the effects of targeted agents used alone.

2010 has been another prolific year in breast cancer research with a number of original observations bringing us closer to personalized care. Studies with novel targeted agents in defined breast cancer subgroups have revealed exciting developments and highlight the importance of patient selection.

The selective estrogen receptor modulator tamoxifen has been used for more than three decades to treat metastatic and early-stage receptor-positive breast cancer and, more recently, to prevent the disease. Biotransformation of tamoxifen to the potent antiestrogen endoxifen is performed by cytochrome P450 (CYP) enzymes, in particular the CYP2D6 isoform. Genetic variants in the CYP2D6 gene may result in CYP2D6 enzymes with reduced or null activity. Strong and intermediate inhibitors of CYP2D6, which may be used to treat hot flashes or psychiatric conditions in breast cancer patients, can also negatively impact enzyme function. Prospective data are lacking, but the balance of current evidence strongly suggests that, compared with women with two wild-type alleles, the presence of two null alleles, and possibly one null allele, predicts reduced tamoxifen metabolism and an inferior outcome in postmenopausal women with early breast cancer who receive adjuvant treatment with the drug. Unfortunately, studies to date have been largely retrospective and the interpretation of their results is limited by examination of archival tissue samples and the inclusion of heterogeneous populations. Although we do not currently recommend routine CYP2D6 testing for women who do not have alternative standard therapies, the use of concomitant strong or intermediate inhibitors of CYP2D6 should be avoided if feasible. This review summarizes the literature to date with a focus on clinically relevant recent studies that examined the association between CYP2D6 polymorphisms and tamoxifen-associated outcomes.

Care of the cancer patient is becoming increasingly individualized. At the fulcrum of such therapeutic decisionmaking lies a relevant and accurate understanding of unique patient characteristics and preferences, and of tumor biology. In a pure sense, prognostic factors reflect tumor biology that may be used to estimate outcome independent of systemic treatment, whereas predictive factors reflect a relative resistance or sensitivity to specific therapy(ies) and are increasingly used to select optimal treatments for an individual patient. Perhaps the best and oldest example of a biomarker with proven clinical utility is the estrogen receptor alpha (ER), the expression of which on breast tumors has served both as a prognostic and predictive biomarker for the last three decades [1]. The Early Breast Cancer Trialists’ Collaborative Group (EBCTCG) 2005 overview clearly demonstrated that tamoxifen substantially reduces the risk for breast cancer recurrence and death across all age groups in patients with ER-positive earlystage breast cancer, whereas patients with ER-negative disease do not benefit from tamoxifen [2, 3]. ER status also predicts response to endocrine therapy in the metastatic setting [4]. In this issue of Breast Cancer Research and Treatment, a well designed and thorough study by Castellano et al. [5] explores the concept of androgen receptor (AR) as a novel prognostic factor in ER-positive breast cancer, and suggests that it may have additional clinical utility in identifying a better prognosis subgroup of luminal B breast cancers.

Lung cancer remains the most common cause of cancer-related death among men and women worldwide. Incremental and significant advances in available systemic treatments, however, have taken place in the last decade to provide improved survival rates and better palliation for patients with non-small-cell and small-cell lung cancer. Superior imaging techniques have enabled the detection of early-stage disease and adjuvant chemotherapy has earned a place for select patients following resection of their tumors. Perhaps the largest growth has been in the area of advanced non-small-cell lung cancer, in which multiple new combination and single-agent systemic therapies have become standard where previously only 'best supportive care' was thought appropriate. In concert with broader applicability of chemotherapy, translational studies have provided the rationale for using molecular markers to identify the patients most likely to benefit from biological and targeted therapies. This review will discuss the current role of chemotherapy in both early and advanced non-small-cell and small-cell lung cancer. Novel targeted systemic therapies and the appropriate selection of treatments for patients based on their tumors' molecular phenotypes and histologies will also be reviewed.

Medical oncologists have traditionally had little to offer patients with metastatic radioactive iodine-resistant thyroid cancer. The 3-year survival rate of patients with differentiated thyroid cancer is less than 50%, with little response obtained from standard cytotoxic chemotherapies. In recent years, however, huge advances have been made in understanding the molecular pathways and cellular pathogenesis of this disease. This knowledge has in turn led to the development of a range of targeted therapies, some specific to thyroid cancer genetic alterations such as the RET/PTC translocation, and others that exploit general malignant properties such as angiogenesis. This review highlights novel targeted agents for the treatment of differentiated and medullary thyroid cancers being studied at this time, and the results of recently published trials. We propose that such patients should be managed, whenever possible, within a clinical trial, in order to access the most promising new drugs for thyroid cancer. In cases where trials are unavailable, we recommend off-label use of the currently available oral multikinase inhibitors such as sorafenib and sunitinib rather than traditional chemotherapies.

The role of ovarian suppression/ablation (OS/OA) in premenopausal women with hormone receptor-positive breast cancer has been evolving for more than a century. It is clear that OS/OA is an effective adjuvant therapy for these women, but despite numerous studies enrolling thousands of women, many unanswered questions remain. In particular, a major question is whether additional benefit is gained with combination treatment comprising luteinizing hormone-releasing hormone (LH-RH) agonists and tamoxifen over tamoxifen alone. Ongoing trials also are assessing the coupling of aromatase inhibitors (traditionally contraindicated in these patients because of paradoxic stimulation of estrogen production) and LH-RH agonists. Any potential disease-free or overall survival advantage of combination treatment must be balanced against a possible increase in adverse effects and impairment of quality of life. This review focuses on new data regarding how to incorporate OS/OA into the rational treatment of this challenging patient population.

Breast cancer is the second leading cause of cancer-related death in women in the United States, and for nearly all with metastatic disease at presentation or relapse it will be incurable. The goals of therapy are to optimize quality of life and, if possible, prolong time to progression of disease and death. For a select group of patients an aggressive surgical approach may be considered. Initial palliation with endocrine therapy should be the primary consideration for patients with metastatic hormone receptor-positive tumors. Cytotoxic chemotherapy is appropriate for those with hormone-refractory disease, rapidly progressive visceral disease, or early relapse after adjuvant therapy. If a tumor overexpresses HER2, targeted treatment with trastuzumab (Herceptin) or lapatinib (Tykerb) is possible. Consequently, accurate determination of the status of these predictive markers in tissue (possibly from a recurrence site) is key. Other novel agents are adding to the wide choices of standard chemotherapies already available. This review offers an approach to the selection of individualized and rational therapies for patients with metastatic breast cancer.

In recent years, we have seen an explosion in knowledge of the genetics and cytogenetics of the plasma-cell neoplasms. This chapter will deal with these advances and will place them in the integrative context of the pathophysiologic basis of the disease, and will discuss the important clinical implications of these abnormalities. We have learned that myeloma can be classified into increasingly definable subgroups that follow a basic global hierarchical grouping. All gene expression profiling strategies have come to similar conclusions and confirm the subgroups previously identified by karyotype, molecular cytogenetics and other genetic studies. At the top level there are two major pathogenetic pathways for the development of plasma cell tumors: one that is associated with hyperdiploidy and one that is characterized by the presence of chromosome translocations involving the immunoglobulin heavy chain locus (IgH). These translocations are seen in up to 60% of patients, but involve a common recurrent chromosome partner in only 40–50% of patients. Several genetic markers are now shown to be associated with a shortened survival. Of these, the most common ones include abnormalities (deletion and monosomy) of chromosome 13, the global state of hypodiploidy and abnormalities of chromosome 1. Many of the translocations observed in MM are also seen in monoclonal gammopathy of undetermined significance (MGUS), even in individuals without progression to full malignant disease for many years. The identification of critical genetic lesions will pave the way for the development of disease-targeted therapy.

2010 has been another prolific year in breast cancer research with a number of original observations bringing us closer to personalized care. Studies with novel targeted agents in defined breast cancer subgroups have revealed exciting developments and highlight the importance of patient selection.

Aim: Heregulin (HRG)-driven ErbB3 signaling mediates resistance to standard-of-care (SOC) cancer therapy in a variety of preclinical models. MM-121, a HRG-blocking anti-ErbB3 antibody, underwent clinical evaluation to determine if patients with advanced malignancies would derive benefit from the addition of MM-121 to their standard therapy. Potential predictive biomarkers were identified from a pre-specified set of mechanistic markers. Study BM+ n/N* BM+ Prevalence PFS HR in study PFS HR in measured BM PFS HR in BM+ PFS HR in BM- Ovarian 69/150 46% 1.03 [0.74-1.42] 1.10 [0.74-1.63] 0.40 [0.21-0.76] 2.02 [1.17-3.50] Lung 36/67 54% 0.82 [0.55-1.21] 0.91 [0.51-1.61] 0.39 [0.18-0.82] 2.43 [1.07-5.55] Breast 21/57 37% 0.75 [0.48-1.15] 0.68 [0.38-1.23] 0.35 [0.13-0.94] 0.99 [0.47-2.08] *n = BM + , N = patients with measured biomarkers Methods: Randomized Phase 2 studies were conducted in: i) platinum-resistant ovarian cancer, ii) EGFR wt NSCLC, and iii) ER/PR + , HER2- mBC. Patients were randomized to SOC therapy, with or without MM-121. Safety and clinical activity data from these studies have previously been presented. Tumor tissue was acquired from each patient and five pre-specified biomarkers were measured and correlated with clinical benefit: HRG, betacellulin, EGFR, HER2, and ErbB3. Protein levels were determined by quantitative IHC (qIHC) and mRNA levels by RT-PCR and RNA in-situ hybridization (RNA-ISH). Results: Among 464 patients (220 ovarian, 115 breast, 129 lung), RNA-ISH data were available from 224 patients (157 ovarian, 67 lung), qIHC from 252 (174 ovarian, 78 lung), and RT-PCR from 175 (105 ovarian, 57 breast, 13 lung). Of the five biomarkers, the most predictive of response was HRG mRNA: patients with detectable HRG in pre-treatment biopsies or high HRG in archived tissue blocks responded poorly to SOC therapy and benefited most from MM-121. In addition, benefit was largely restricted to patients with low ErbB2. Hazard ratios for PFS were calculated, defining biomarker positive (BM+) patients: Ovarian cancer, detectable HRG and low ErbB2; Lung cancer, detectable HRG; and, Breast cancer, high HRG. PFS hazard ratios with 95% CI and prevalence of the BM+ and BM- subpopulations are provided below. Conclusions: Heregulin is a potential biomarker for poor response to SOC therapy and a potential predictor of clinical benefit from MM-121 in late-stage ovarian, lung, and breast cancers. Disclosure: G. MacBeath is an employee of Merrimack Pharmaceuticals and holds stock in the company; B. Adiwijaya is an employee of Merrimack Pharmaceuticals, the sponsor of this clinical research, and holds stock in the company; J. Liu is an unpaid advisor for Merrimack Pharmaceuticals and was a Principal Investigator for one of the clinical studies included in this analysis; L.V. Sequist is an upaid advisor for Merrimack Pharmaceuticals and was a Principal Investigator of one of the clinical studies included in this analysis; E. Pujade-Lauraine serves as an upaid advisor to Merrimack Pharmaceuticals and Sanofi. He was also a lead investigator for one of the clinical studies included in this analysis; M. Higgins is an unpaid advisor to Merrimack Pharmaceuticals and Sanofi. She was a Principal Investigator of one of the clinical studies included in this analysis; I. Tabah-Fisch is an employee of Sanofi, a sponsor of the clinical studies summarized in this abstract, and holds stock in the company; J. Pearlberg is an employee of Sanofi, a sponsor of this clinical research, and holds stock in the company; V. Moyo, W. Kubasek, R. Nering and A. Czibere: Is an employee of Merrimack Pharmaceuticals, a sponsor of the clinical research, and holds stock in the company.

587 Background: Ligand-driven ErbB3 signaling has been implicated as a mechanism of resistance to conventional therapies across multiple malignancies, including endocrine resistant metastatic breas...

TPS654 Background: Cell cycle inhibition is a target of interest for novel cancer therapeutics. P is an orally active inhibitor of CDK4/6, causing cell cycle arrest at the G1-S transition. In an in...

11019 Background: PIK3CA is mutated in up to 30% of breast cancers. Classically somatic mutations are identified by Sanger sequencing of the primary tumor specimen. However third generation droplet digital PCR technologies offer a novel platform for quantitative mutation detection with improved sensitivity. Methods: Thirty stage I-III breast cancer patients were consented on an IRB-approved prospective repository study at Johns Hopkins for collection of their primary breast tumor specimen. Formalin-fixed paraffin embedded (FFPE) samples were analyzed by standard sequencing for three PIK3CA hotspot mutations. The DNA from these samples was then analyzed using the RainDrop digital PCR platform with TaqMan probes in a triplex format to simultaneously detect and quantitate hotspot mutations and genome equivalents. Results are expressed as a percentage of mutant to wild-type PIK3CA molecules for each sample. Results: Standard sequencing of all tumors (n=30) identified seven PIK3CA Exon 20 mutations (H1047R) and three Exon 9 mutations (E545K). Samples were scored as PIK3CA mutation positive by digital PCR if the tumor DNA contained at least 5% mutant molecules. All ten mutations identified by sequencing were verified by digital PCR with quantities of mutant molecules ranging from 20.3-55.6% in a given sample. Digital PCR identified additional PIK3CA mutations that were wild type by standard sequencing including three mutant Exon 20 samples, two mutant Exon 9 samples and one sample with an Exon 20 and Exon 9 mutation. Quantities of mutant molecules in these additional samples ranged from 5-28.9%. Conclusions: RainDrop digital PCR offers improved sensitivity and quantification for detecting PIK3CA mutations in FFPE samples using nanograms of DNA. Additional mutations identified by digital PCR may reflect genetic heterogeneity or possibly tissue contamination. The clinical utility of identifying a small proportion of mutations is unknown but may impact eligibility for targeted therapies and clinical trials. Ongoing studies will also address whether the identification of solid tumor mutations in circulating cell-free plasma DNA by digital PCR can improve diagnostics and aid in therapeutic decisions.

The ability to accurately detect somatic cancer DNA alterations from cell free circulating plasma tumor DNA (ptDNA) using next generation genomic technologies has many potential applications for clinical oncology. The initial use of this technology has been to detect point mutations in peripheral blood that could serve as predictors of response to various targeted therapies. Thus the development of a “liquid biopsy” that could easily match the mutational status of a given cancer with a specific therapy had great therapeutic implications. For example, the ability to assess certain epidermal growth factor receptor (EGFR) mutations via blood versus an invasive lung biopsy would allow for the rapid determination of whether a patient would be a candidate for small molecule EGFR inhibitors such as gefitinib or erlotinib. We initially sought to evaluate the feasibility of detecting PIK3CA mutations in circulating ptDNA from patients with metastatic breast cancer using a novel technique of digital polymerase chain reaction (PCR) called BEAMing (for Beads, Emulsions, Amplification, Magnetics). We demonstrated that BEAMing is both sensitive and specific for identifying PIK3CA mutations in metastatic breast cancer patients, though we also confirmed the work of other groups that PIK3CA mutation status can change with progression to metastatic disease. An overview of these data will be presented. While these studies demonstrated the feasibility of using ptDNA in metastatic patients as a liquid biopsy for detecting specific cancer mutations, we are now focusing efforts to exploit the quantitative nature of digital PCR technology. Specifically, by analyzing the amount of ptDNA before and after primary breast surgery in early stage breast cancer patients, we will identify which patients truly have residual microscopic disease post surgery and therefore would be the most appropriate candidates for additional systemic therapies. Thus, in contrast to the current paradigm of “over” treating breast cancer patients in the adjuvant setting, detection of ptDNA using next generation digital PCR technologies will enable us to make rational decisions regarding which patients truly have need for adjuvant systemic therapies. Preliminary data and ongoing studies will be discussed as well as the implementation of these technologies in future clinical trials. Citation Format: Julia A. Beaver, Patricia Valda, Danijela Jelovac, Michaela J. Higgins, Ben H. Park. Plasma tumor DNA: Changing the paradigm for administering systemic therapies. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr SY11-01. doi:10.1158/1538-7445.AM2013-SY11-01

Introduction: Breast cancer is increasingly being recognized as a heterogeneous disease and previous studies have reported various oncogenic mutations in breast cancer specimens. However, a validated methodology for clinical assessment of mutation profiles is lacking. Applying such technologies will be increasingly important to accelerate development of targeted therapies toward tumor-specific oncogene pathways. Utilizing a high-throughput genotyping platform we evaluated the commonly described somatic mutations in tumor tissue among women diagnosed with metastatic breast cancer. Methods: We developed a CLIA (Clinical Laboratory Improvement Amendments) validated, highly sensitive multiplexed PCR-based assay (SNaPshot) to simultaneously identify 130 previously described mutations in 13 cancer genes using DNA derived from formalin-fixed, paraffin-embedded (FFPE) tissue. Data regarding demographics, tumor phenotype based on estrogen and progesterone receptor (ER, PR) status, HER-2 (Human Epidermal growth factor Receptor-2) status, BRCA carrier status, and clinical outcomes, was abstracted from clinical charts. Results: A total of 138 tumors from women with metastatic breast cancer, median age 69 (range 29-82), were analyzed. In this study, 34.7% of tumors had a detectable mutation, with PIK3CA mutation (70.8%) being the most common mutation detected followed by TP53 (27.1%), and Akt (4%). Unanticipated mutations in KRAS and BRAF were observed at lower frequencies. Detectable mutations were seen in all tumor sub-types although the frequency varied by tumor phenotype: ER+/PR+ (34.5%), ER+/PR- (52.6%), HER-2+ (44.4%), and triple negative (23.2%) tumors. Similarly, while the type of mutation varied somewhat by tumor phenotype, the common driver mutations were seen in all tumor subtypes. For PIK3CA mutations: ER+/PR+ (27.7%), ER+/PR- (42.8%), HER-2+ (29.6%), triple negative (6.7%) tumors, and for TP53 mutations: ER+/PR+ (3.6%), ER+/PR- (14.2%), HER-2+ (18.5%) and triple negative (10%) tumors. Correlation with clinical outcomes is ongoing. BRCA1/2 carriers were less likely to have a detectable somatic mutation in their tumor (15.3%) than patients with negative BRCA1/2 status (25.8%). Only 4 patients (2.8%) had more than one detectable somatic mutation. Conclusion: Oncogenic driver mutations can be detected by SNaPshot from routinely-collected FFPE tissue specimens obtained from women seen in the oncology clinic for metastatic breast cancer. While the type and frequency of mutation varies somewhat by tumor phenotype, the common oncogenic mutations are seen in all breast cancer subtypes and are often found in isolation. These findings highlight the necessity for broad tumor mutational analysis, independent of traditional breast cancer subtype, to efficiently tailor personalized therapies in the clinic based on individual tumor genetic profiles. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 962. doi:1538-7445.AM2012-962

1505 Background: Observational studies have reported a decreased incidence of breast cancer in users of HMG Co-A reductase inhibitors. The primary objective of this phase II study was to screen pot...