Tejal Amar Patel

Inhibition of iNOS as a novel effective targeted therapy against triple-negative breast cancer

IntroductionTriple-negative breast cancer (TNBC) is an aggressive form of breast cancer with no effective targeted therapy. Inducible nitric oxide synthase (iNOS) is associated with poor survival in patients with breast cancer by increasing tumor aggressiveness. This work aimed to investigate the potential of iNOS inhibitors as a targeted therapy for TNBC. We hypothesized that inhibition of endogenous iNOS would decrease TNBC aggressiveness by reducing tumor initiation and metastasis through modulation of epithelial-mesenchymal transition (EMT)-inducing factors.MethodsiNOS protein levels were determined in 83 human TNBC tissues and correlated with clinical outcome. Proliferation, mammosphere-forming efficiency, migration, and EMT transcription factors were assessed in vitro after iNOS inhibition. Endogenous iNOS targeting was evaluated as a potential therapy in TNBC mouse models.ResultsHigh endogenous iNOS expression was associated with worse prognosis in patients with TNBC by gene expression as well as immunohistochemical analysis. Selective iNOS (1400xa0W) and pan-NOS (L-NMMA and L-NAME) inhibitors diminished cell proliferation, cancer stem cell self-renewal, and cell migration in vitro, together with inhibition of EMT transcription factors (Snail, Slug, Twist1, and Zeb1). Impairment of hypoxia-inducible factor 1α, endoplasmic reticulum stress (IRE1α/XBP1), and the crosstalk between activating transcription factor 3/activating transcription factor 4 and transforming growth factor β was observed. iNOS inhibition significantly reduced tumor growth, the number of lung metastases, tumor initiation, and self-renewal.ConclusionsConsidering the effectiveness of L-NMMA in decreasing tumor growth and enhancing survival rate in TNBC, we propose a targeted therapeutic clinical trial by re-purposing the pan-NOS inhibitor L-NMMA, which has been extensively investigated for cardiogenic shock as an anti-cancer therapeutic.

Cell-free DNA as a molecular tool for monitoring disease progression and response to therapy in breast cancer patients.

Due to the spatial and temporal genomic heterogeneity of breast cancer, genomic sequencing obtained from a single biopsy may not capture the complete genomic profile of tumors. Thus, we propose that cell-free DNA (cfDNA) in plasma may be an alternate source of genomic information to provide comprehensive data throughout a patient’s clinical course. We performed a retrospective chart review of 100 patients with stage 4 or high-risk stage 3 breast cancer. The degree of agreement between genomic alterations found in tumor DNA (tDNA) and cfDNA was determined by Cohen’s Kappa. Clinical disease progression was compared to mutant allele frequency using a two-sided Fisher’s exact test. The presence of mutations and mutant allele frequency was correlated with progression-free survival (PFS) using a Cox proportional hazards model and a log-rank test. The most commonly found genomic alterations were mutations in TP53 and PIK3CA, and amplification of EGFR and ERBB2. PIK3CA mutation and ERBB2 amplification demonstrated robust agreement between tDNA and cfDNA (Cohen’s kappaxa0=xa00.64 and 0.77, respectively). TP53 mutation and EGFR amplification demonstrated poor agreement between tDNA and cfDNA (Cohen’s kappaxa0=xa00.18 and 0.33, respectively). The directional changes of TP53 and PIK3CA mutant allele frequency were closely associated with response to therapy (pxa0=xa00.002). The presence of TP53 mutation (pxa0=xa00.0004) and PIK3CA mutant allele frequency [pxa0=xa00.01, HR 1.074 (95xa0% CI 1.018–1.134)] was excellent predictors of PFS. Identification of selected cancer-specific genomic alterations from cfDNA may be a noninvasive way to monitor disease progression, predict PFS, and offer targeted therapy.

RC0639: phase II study of paclitaxel, trastuzumab, and lapatinib as adjuvant therapy for early stage HER2-positive breast cancer.

Lapatinib adds to the efficacy of trastuzumab in preclinical models and also in the neo-adjuvant setting. This study assesses the safety and feasibility of adding lapatinib to paclitaxel and trastuzumab (THL) as part of the adjuvant therapy for HER2-positive breast cancer (HER2+ BC). In this single-arm phase II study, patients with stages I–III HER2+ BC received standard anthracycline-based chemotherapy followed by weekly taxane, with concurrent standard trastuzumab, plus daily lapatinib for a total of 12xa0months. The primary endpoint was symptomatic congestive heart failure, secondary endpoints included overall safety. A total of 109 eligible patients were enrolled. Median follow-up is 4.3xa0years. No patients experienced congestive heart failure while on treatment. Mean left ventricular ejection fraction at baseline and at the end of THL were 63.6xa0% (Nxa0=xa0109, SDxa0=xa05.7) and 59.8xa0% (Nxa0=xa098, SDxa0=xa08.1), respectively [mean change −3.95xa0% (Nxa0=xa098, SDxa0=xa08.3), pxa0<xa00.001]. One hundred and two patients initiated post-AC treatment; of them, 31xa0% experienced grade 3 (no G4) diarrhea with lapatinib at 750xa0mg/day. The addition of lapatinib to paclitaxel and trastuzumab following AC does not add cardiac toxicity. Lapatinib dose of 750xa0mg/day in combination with standard chemotherapy plus trastuzumab has acceptable overall tolerability.

Correlating mammographic and pathologic findings in clinical decision support using natural language processing and data mining methods

A key challenge to mining electronic health records for mammography research is the preponderance of unstructured narrative text, which strikingly limits usable output. The imaging characteristics of breast cancer subtypes have been described previously, but without standardization of parameters for data mining.

Deep learning analytics for diagnostic support of breast cancer disease management

Breast cancer continues to be one of the leading causes of cancer death among women. Mammogram is the standard of care for screening and diagnosis of breast cancer. The American College of Radiology developed the Breast Imaging Reporting and Data System (BI-RADS) lexicon to standardize mammographic reporting to assess cancer risk and facilitate biopsy decision-making. However, because substantial inter-observer variability remains in the application of the BI-RADS lexicon, including inappropriate term usage and missing data, current biopsy decision-making accuracy using the unstructured free text or semi-structured reports varies greatly. Hence, incorporating novel and accurate technique into breast cancer decision-making data is critical. Here, we combined natural language processing and deep learning methods to develop an analytic model that targets well-characterized and defined specific breast suspicious patient subgroups rather than a broad heterogeneous group for diagnostic support of breast cancer management.

Abstract P6-03-05: Cell-free DNA as molecular tool for monitoring disease progression and response to therapy in breast cancer patients

Background: Identification of cancer-specific genes from breast cancer cells was instrumental in the advancement of targeted breast cancer therapy. However, with genomic heterogeneity within the breast cancer and evolution of cancer over time, genomic sequencing obtained from a single biopsy site may not capture the complete genomic profile. Thus, circulating cell-free DNA (cfDNA), isolated from plasma, is potentially a non-invasive source of identifying cancer-specific genomic alterations and may provide comprehensive genomic data throughout a patient9s clinical course as they undergo anti-cancer therapy. Method: We performed a retrospective chart review of 100 patients with stage 4 or high-risk stage 3 breast cancer who were tested for cfDNA genomic alterations. The most common actionable cancer specific genomic alterations were identified. In 23 patients who also had genomic analysis from tumor DNA (tDNA), an analysis using the Cohen9s Kappa statistic was performed to determine the degree of agreement between genomic alterations found in tDNA and cfDNA. The proportion of patients with clinical disease progression between two cohorts determined by change in mutant allele frequency was compared using two-sided Fisher9s exact test. Patients who received targeted therapy based on the identified genomic alteration were followed to determine response to therapy. Results: In cfDNA of 100 breast cancer patients, the most commonly found cancer specific genomic alterations were TP53, PIK3CA, EGFR amplification, and ERBB2 amplification, with incidence rates 27%, 22%, 9%, and 7%, respectively. In tDNA of 23 patients, incidence rates were 65%, 26%, 9%, and 13%. PIK3CA and ERBB2 amplification demonstrated robust agreement between tDNA and cfDNA (Cohen9s Kappa= 0.64 and 0.77, respectively). TP53 and EGFR amplification demonstrated poor agreement between tDNA and cfDNA (Cohen9s Kappa= 0.18 and 0.33, respectively). There were 22 patients who had baseline and post-therapy mutant allele frequency measurements of TP53 and PIK3CA. Directional change of mutant allele frequency was closely associated with patient9s response to therapy (p=0.0017). 8 out of 8 patients (100%) who had progression of disease had increase in mutant allele frequency. 10 out of 14 patients (71%) of patients who responded to therapy had decrease in mutant allele frequency. 6 patients who were found to have ERBB2 amplification were initiated on anti-HER2 cancer therapy. 5 of 6 patients (83%) had clinical response to therapy, while one patient had progression of disease. 3 patients who were found to have EGFR amplification (2 in cfDNA, 1 in tDNA) were initiated on anti-EGFR therapy. 2 of 3 patients (67%) had clinical response to therapy, while one patient had progression of disease. Conclusion: There is no definite agreement between genomic alterations found in tDNA and those found in cfDNA. Whether this is due to tumor heterogeneity or tumor evolution over time with administration of anti-cancer treatment remains unknown. However, identification of selected cancer specific genomic alterations from cfDNA may be a non-invasive tool to monitor disease progression and response to breast cancer therapy. Citation Format: Liang DH, Patel A, Ensor JE, Patel TA, Chang JC, Rodriguez AA. Cell-free DNA as molecular tool for monitoring disease progression and response to therapy in breast cancer patients. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-03-05.

Abstract CT304: Phase Ib trial of trastuzumab emtansine (TE) in combination with lapatinib (L) plus nab-paclitaxel (A) in metastatic HER2-neu overexpressed breast cancer patients: STELA trial results

Background: Multiple large randomized clinical trials have demonstrated that dual HER2 targeted therapies are synergistic and result in improved efficacy. We conducted a phase Ib trial of trastuzumab-emtansine (TE) and lapatinib (L), together with Nab paclitaxel (A) in patients with HER2 over-expressed stage IV breast cancer. Methods: Key inclusion criteria are stage IV HER2 positive breast cancer, LVEF ≥ 45%, and Peripheral neuropathy Results: Nine patients, median age 47 (range 44-64) years were enrolled. All patients are currently off the study. The DLTs were grade 3 diarrhea (n = 1) and grade 3 elevated transaminase (n = 1). Grade 3-4 hematological toxicities included neutropenia (N = 6) and thrombocytopenia (N = 1). Other AEs included grade 1-2 mucositis (n = 2), diarrhea (N = 2), and liver function tests abnormality (N = 5). The 24 hour trough levels of each of the drug were within the range of the values reported in the literature. The MTD of TE, L and A was reached at: TE 3.0 mg/kg, Lapatinib 750mg and Abraxane (A) 80 mg/m2. Eight patients, with a median of 1 prior metastatic therapy (range 0-5) were evaluable for response. Five patients, 62.5% derived clinical benefit, including 1 patient with complete response and 4 patients with partial response. Conclusions: TE plus L and A therapy was well tolerated with antitumor activity observed. STELA Ib trial has been expanded to include twelve additional patients for safety and efficacy evaluation. Citation Format: Tejal Patel, Jaime Mejia, Angel Rodriguez, Jenny Chang. Phase Ib trial of trastuzumab emtansine (TE) in combination with lapatinib (L) plus nab-paclitaxel (A) in metastatic HER2-neu overexpressed breast cancer patients: STELA trial results. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr CT304. doi:10.1158/1538-7445.AM2015-CT304