Clinical outcomes of patients with acute myeloid leukemia and cardiovascular disease.

Incidence of both acute myeloid leukemia (AML) and cardiovascular disease (CVD) increases with age. We evaluated whether pre-existing CVD impacts clinical outcomes in AML. We retrospectively evaluated 291 consecutive adult AML patients treated at our institution, 2014-2020. Pretreatment comorbidities were identified by chart review. Outcomes included complete remission (CR) and CR with incomplete count recovery (CRi) rates, disease-free survival (DFS), overall survival (OS) and incidence of cardiovascular adverse events. CVD was present in 34% of patients at AML diagnosis. CVD patients had worse performance status (p=0.03) and more commonly had secondary AML (p=0.03) and received hypomethylating (HMA) agent-based therapy (72% vs 38%, p< 0.001). CVD (0.45 vs 0.71, p<0.001) and diabetes mellitus (HR= 0.24, 95% CI: 0.08 - 0.8, p= 0.01) were associated with lower probability of achieving CR/CRi. Accounting for age, performance status (PS), complex karyotype, secondary disease and treatment, CVD patients had shorter OS (HR=1.5, 95% CI: 1.1-2.2, p=0.002), with 1- and 3-year OS 44% vs 67% and 25% vs 40%, respectively, but there was no difference in cumulative incidence of relapse between patients with vs without CVD. Thus, CVD is an independent risk factor for lower response rate and shorter survival in AML patients.

Microtubule disruption reduces metastasis more effectively than primary tumor growth.

Clinical cancer imaging focuses on tumor growth rather than metastatic phenotypes. The microtubule-depolymerizing drug, Vinorelbine, reduced the metastatic phenotypes of microtentacles, reattachment and tumor cell clustering more than tumor cell viability. Treating mice with Vinorelbine for only 24 h had no significant effect on primary tumor survival, but median metastatic tumor survival was extended from 8 to 30 weeks. Microtentacle inhibition by Vinorelbine was also detectable within 1 h, using tumor cells isolated from blood samples. As few as 11 tumor cells were sufficient to yield 90% power to detect this 1 h Vinorelbine drug response, demonstrating feasibility with the small number of tumor cells available from patient biopsies. This study establishes a proof-of-concept that targeted microtubule disruption can selectively inhibit metastasis and reveals that existing FDA-approved therapies could have anti-metastatic actions that are currently overlooked when focusing exclusively on tumor growth.

Comparison of efficacy and toxicity of chemoradiation regimens for head and neck squamous cell carcinoma primary treatment.

BACKGROUND: The best chemoradiation regimen to treat locally and regionally advanced head and neck squamous cell carcinoma (HNSCC) is yet to be established. METHODS: We compared overall survival (OS) and adverse events following chemoradiation regimens (high-dose [HDC] or low-dose [LDC] cisplatin, or carboplatin [CB]) in HNSCC cases selected from SEER-Medicare linked database. RESULTS: Of the 1335 cases who underwent radiotherapy, 264 received HDC, 259 received LDC, and 353 received CB, concurrently. Compared to chemoradiation with HDC, using LDC or CB, or radiotherapy alone were associated with an increasingly worse OS; hazard ratios were 1.33, p = 0.03; 1.35, p = 0.02; and 2.12, p < 0.001; respectively. There were no differences in the rates of adverse events between the three chemoradiation regimens. CONCLUSION: Chemoradiation regimen using HDC appears to be the best primary treatment for locally and regionally advanced HNSCC. Nonetheless, prospective large studies are warranted to further determine its absolute benefit.

Adherence to Guideline-Concordant Care and Its Effect on Survival in Black Patients with Head and Neck Cancers: A SEER-Medicare Analysis.

BACKGROUND: In head and neck squamous cell carcinoma (HNSCC), Black patients continue to have worse survival when compared with White patients. The cause of this disparity is multifaceted and cannot be explained by one etiology alone. To investigate this disparity, we used the Surveillance, Epidemiology, and End Results (SEER)-Medicare linked database to examine adherence to guideline-concordant care (GCC) as defined by the National Comprehensive Cancer Network. PATIENTS AND METHODS: In this retrospective study, Medicare beneficiaries diagnosed with nonmetastatic HNSCC as their first cancer between 1992 and 2011 and a random sample of Medicare controls matched to cases (2:1) diagnosed between 2004 and 2011 (n = 16,378), were included in this analysis. RESULTS: Black patients were less likely to receive GCC in advanced-stage oropharyngeal (66% vs. 74%; p = .007) and oral cavity (56% vs. 71%; p = .002) squamous cell carcinoma (SCC). On multivariate analysis, Black patients demonstrated an increased risk of death in advanced oropharyngeal (p < .001), oral cavity (p = .01), and hypopharyngeal (p = .01) SCC. CONCLUSION: Black patients did not consistently receive GCC across HNSCC subsites, contributing to the poorer outcomes seen when compared with White patients. Future research should focus on elucidating the mechanisms behind the non-GCC given to Black patients with HNSCC and other factors that may contribute to this disparity such as tumor biology. IMPLICATIONS FOR PRACTICE: Black patients with head and neck cancer (HNC) continue to have worse survival than White patients. This study examined if the racial disparity in survival from curable HNC is affected by adherence to guideline-concordant care (GCC). It was discovered that Black patients were less likely to receive appropriate treatment in certain HNCs. Although adherence to proper therapy was associated with improved survival in patients with HNC, the difference in survival, where Black patients had inferior outcomes, remained. This analysis uncovered a major contributor to the disparity seen in patients with HNC. As such, cancer centers serving a predominantly Black population with HNC can design specific clinical interventions to ensure GCC for all patients, potentially improving outcomes for everyone.

Draft Genome Sequence of Pseudomonas aeruginosa Strain PA14-UM.

Pseudomonas aeruginosa is a Gram-negative nosocomial pathogen that is a leading cause of morbidity and mortality in cystic fibrosis patients and immunocompromised individuals worldwide. The isolate examined in this study, PA14-UM, is a well-characterized isolate utilized in studies from the University of Maryland.

Decreased nonspecific adhesivity, receptor-targeted therapeutic nanoparticles for primary and metastatic breast cancer.

Development of effective tumor cell-targeted nanodrug formulations has been quite challenging, as many nanocarriers and targeting moieties exhibit nonspecific binding to cellular, extracellular, and intravascular components. We have developed a therapeutic nanoparticle formulation approach that balances cell surface receptor-specific binding affinity while maintaining minimal interactions with blood and tumor tissue components (termed "DART" nanoparticles), thereby improving blood circulation time, biodistribution, and tumor cell-specific uptake. Here, we report that paclitaxel (PTX)-DART nanoparticles directed to the cell surface receptor fibroblast growth factor-inducible 14 (Fn14) outperformed both the corresponding PTX-loaded, nontargeted nanoparticles and Abraxane, an FDA-approved PTX nanoformulation, in both a primary triple-negative breast cancer (TNBC) model and an intracranial model reflecting TNBC growth following metastatic dissemination to the brain. These results provide new insights into methods for effective development of therapeutic nanoparticles as well as support the continued development of the DART platform for primary and metastatic tumors.

Definitive radiation with concurrent cetuximab vs. radiation with or without concurrent cytotoxic chemotherapy in older patients with squamous cell carcinoma of the head and neck: Analysis of the SEER-medicare linked database.

OBJECTIVE: To evaluate OS and toxicity after definitive radiation with concurrent cetuximab (CTX-RT) compared to radiation with concurrent cytotoxic chemotherapy (CRT) in older HNSCC patients via the SEER-Medicare linked database. MATERIALS AND METHODS: We used the SEER-Medicare linked database to evaluate OS in HNSCC patients (Oropharynx, Larynx, Hypopharynx, Nasopharynx) diagnosed over 2005-2011, following FDA approval of cetuximab in combination with radiation therapy (RT) in March 2006. RESULTS: 2135 beneficiaries were identified. Median age was 73 (66-104) years. Primary was oropharynx (61%), hypopharynx (15%), nasopharynx (5%), and larynx (19%). CRT was platinum based in 82% of patients. CTX-RT was associated with worse OS compared to CRT (P < 0.005), and similar OS to RT (P = 0.21); 5-year OS was 46% for CRT, 35% for CTX-RT, 32% for RT. Patients were more likely to receive CTX-RT vs. CRT if they had oropharyngeal vs nasopharyngeal primary, Charlson comorbidity index 2 vs 0, older age at diagnosis. Multivariable Cox regression showed that CTX-RT was associated with a higher risk of death compared to CRT (hazard ratio = 1.23, 1.07-1.42; p = 0.005), after stratifying by stage and primary site, and adjusting for gender, race, age, income, Charlson comorbidity index, marital status, hospital type, and year of diagnosis. There were no differences in dysphagia, gastrostomy tube placement, pneumonia, and weight loss over the first 12 months after diagnosis. CONCLUSION: Despite the limitations to comparative effectiveness evaluation in population-based registries, our data suggest that cytotoxic chemotherapy should be used with RT for eligible older HNSCC patients.

Patient-reported Adherence to Adjuvant Aromatase Inhibitor Therapy Using the Morisky Medication Adherence Scale: An Evaluation of Predictors.

OBJECTIVES: Endocrine therapy is part of standard adjuvant therapy for patients with hormone receptor-positive breast cancer and has been shown to improve recurrence-free and overall survival. However, adherence to endocrine therapy is suboptimal and is difficult to measure. In this study we evaluate the feasibility of using the Morisky Medication Adherence Scale (MMAS) to assess patient adherence to aromatase inhibitor (AI) therapy. METHODS: Patients with stage 1 to 3, hormone receptor-positive breast cancer receiving adjuvant AI therapy were prospectively enrolled on an Institutional Review Board approved protocol. The MMAS questionnaire was administered to each patient and adherence was measured. Information on duration of AI therapy, patient and tumor characteristics, and treatment was collected. A multivariable logit model approach was utilized to evaluate potential barriers to adherence. RESULTS: Between 2011 and 2014, 100 patients were enrolled. The distribution of adherence levels was 13% low, 37% medium, and 50% high. High adherence was reported more frequently in white women (58%), patients with stage 2 and 3 disease (54%), and patients who did not receive chemotherapy (62%). Multivariable analysis demonstrated that higher adherence was more likely in white women compared with African American women (estimated odds ratio=2.8). CONCLUSIONS: Using the MMAS, only 50% of women with stage 1 to 3 breast cancer reported high adherence to AI therapy, consistent with other reports showing suboptimal adherence to adjuvant endocrine therapy. The MMAS allows for the rapid assessment of adherence to oral adjuvant endocrine therapy and is valuable in a busy clinical setting.

Ultrasound use during cardiopulmonary resuscitation is associated with delays in chest compressions.

AIM: High-quality chest compressions are a critical component of the resuscitation of patients in cardiopulmonary arrest. Point-of-care ultrasound (POCUS) is used frequently during emergency department (ED) resuscitations, but there has been limited research assessing its benefits and harms during the delivery of cardiopulmonary resuscitation (CPR). We hypothesized that use of POCUS during cardiac arrest resuscitation adversely affects high-quality CPR by lengthening the duration of pulse checks beyond the current cardiopulmonary resuscitation guidelines recommendation of 10s. METHODS: We conducted a prospective cohort study of adults in cardiac arrest treated in an urban ED between August 2015 and September 2016. Resuscitations were recorded using video equipment in designated resuscitation rooms, and the use of POCUS was documented and timed. A linear mixed-effects model was used to estimate the effect of POCUS on pulse check duration. RESULTS: Twenty-three patients were enrolled in our study. The mean duration of pulse checks with POCUS was 21.0s (95% CI, 18-24) compared with 13.0s (95% CI, 12-15) for those without POCUS. POCUS increased the duration of pulse checks and CPR interruption by 8.4s (95% CI, 6.7-10.0 [p<0.0001]). Age, body mass index (BMI), and procedures did not significantly affect the duration of pulse checks. CONCLUSIONS: The use of POCUS during cardiac arrest resuscitation was associated with significantly increased duration of pulse checks, nearly doubling the 10-s maximum duration recommended in current guidelines. It is important for acute care providers to pay close attention to the duration of interruptions in the delivery of chest compressions when using POCUS during cardiac arrest resuscitation.

Non-specific binding and steric hindrance thresholds for penetration of particulate drug carriers within tumor tissue.

Therapeutic nanoparticles (NPs) approved for clinical use in solid tumor therapy provide only modest improvements in patient survival, in part due to physiological barriers that limit delivery of the particles throughout the entire tumor. Here, we explore the thresholds for NP size and surface poly(ethylene glycol) (PEG) density for penetration within tumor tissue extracellular matrix (ECM). We found that NPs as large as 62nm, but less than 110nm in diameter, diffused rapidly within a tumor ECM preparation (Matrigel) and breast tumor xenograft slices ex vivo. Studies of PEG-density revealed that increasing PEG density enhanced NP diffusion and that PEG density below a critical value led to adhesion of NP to ECM. Non-specific binding of NPs to tumor ECM components was assessed by surface plasmon resonance (SPR), which revealed excellent correlation with the particle diffusion results. Intravital microscopy of NP spread in breast tumor tissue confirmed a significant difference in tumor tissue penetration between the 62 and 110nm PEG-coated NPs, as well as between PEG-coated and uncoated NPs. SPR assays also revealed that Abraxane, an FDA-approved non-PEGylated NP formulation used for cancer therapy, binds to tumor ECM. Our results establish limitations on the size and surface PEG density parameters required to achieve uniform and broad dispersion within tumor tissue and highlight the utility of SPR as a high throughput method to screen NPs for tumor penetration.

Upregulation of Cyclooxygenase-2/Prostaglandin E2 (COX-2/PGE2) Pathway Member Multiple Drug Resistance-Associated Protein 4 (MRP4) and Downregulation of Prostaglandin Transporter (PGT) and 15-Prostaglandin Dehydrogenase (15-PGDH) in Triple-Negative Breast Cancer.

Elevated levels of cyclooxygenase-2 (COX-2) and prostaglandin E2 (PGE2) are indicators of a poor prognosis in breast cancer. Using several independent publicly available breast cancer gene expression databases, we investigated other members of the PGE2 pathway. PGE2 is produced by COX-2 and actively exported by multiple drug resistance-associated protein 4 (MRP4) into the extracellular microenvironment, where PGE2 can bind four cognate EP receptors (EP1-EP4) and initiate diverse biological signaling pathways. Alternatively, PGE2 is imported via the prostaglandin transporter (PGT) and metabolized by 15-prostaglandin dehydrogenase (15-PGDH/HPGD). We made the novel observation that MRP4, PGT, and 15-PGDH are differentially expressed among distinct breast cancer molecular subtypes; this finding was confirmed in independent datasets. In triple-negative breast cancer, the observed gene expression pattern (high COX-2, high MRP4, low PGT, and low 15-PGDH) would favor high levels of tumor-promoting PGE2 in the tumor microenvironment that may contribute to the overall poor prognosis of triple-negative breast cancer.

The RUNX2 Transcription Factor Negatively Regulates SIRT6 Expression to Alter Glucose Metabolism in Breast Cancer Cells.

Activation of genes promoting aerobic glycolysis and suppression of mitochondrial oxidative phosphorylation is one of the hallmarks of cancer. The RUNX2 transcription factor mediates breast cancer (BC) metastasis to bone and is regulated by glucose availability. But, the mechanisms by which it regulates glucose metabolism and promotes an oncogenic phenotype are not known. RUNX2 expression in luminal BC cells correlated with lower estrogen receptor-α (ERα) levels, anchorage-independent growth, expression of glycolytic genes, increased glucose uptake, and sensitivity to glucose starvation, but not to inhibitors of oxidative phosphorylation. Conversely, RUNX2 knockdown in triple-negative BC cells inhibited mammosphere formation and glucose dependence. RUNX2 knockdown resulted in lower LDHA, HK2, and GLUT1 glycolytic gene expression, but upregulation of pyruvate dehydrogenase-A1 (PDHA1) mRNA and enzymatic activity, which was consistent with lower glycolytic potential. The NAD-dependent histone deacetylase, SIRT6, a known tumor suppressor, was a critical regulator of these RUNX2-mediated metabolic changes. RUNX2 expression resulted in elevated pAkt, HK2, and PDHK1 glycolytic protein levels that were reduced by ectopic expression of SIRT6. RUNX2 also repressed mitochondrial oxygen consumption rates (OCR), a measure of oxidative phosphorylation (respiration). Overexpression of SIRT6 increased respiration in RUNX2-positive cells, but knockdown of SIRT6 in cells expressing low RUNX2 decreased respiration. RUNX2 repressed SIRT6 expression at both the transcriptional and post-translational levels and endogenous SIRT6 expression was lower in malignant BC tissues or cell lines that expressed high levels of RUNX2. These results support a hypothesis whereby RUNX2-mediated repression of the SIRT6 tumor suppressor regulates metabolic pathways that promote BC progression.

Disparities in black and white patients with multiple myeloma referred for autologous hematopoietic transplantation: a single center study.

BACKGROUND: Racial disparity in the incidence of multiple myeloma is well established; however, to the authors' knowledge, little is known regarding the impact of racial differences on disease characteristics, response to therapy, and clinical outcome. METHODS: The authors studied 453 patients (174 of whom were black and 279 of whom were white) who underwent transplant between 2000 and 2013. The median follow-up was 4.4 years. RESULTS: Black patients were significantly younger than white patients (median age, 54 years vs 59 years; P<.0001), more frequently presented with anemia (P = .04), had more of the immunoglobulin G isotype (P<.001), and had a borderline favorable cytogenetic risk (P = .06). Overall response to induction was similar, but deeper responses were observed in more white patients compared with black patients receiving immunomodulatory drug-based induction (P = .02). Referral for transplant was significantly delayed in black individuals (median, 1.3 years vs 0.9 years; P = .003). Overall survival from the time of transplant was similar for black and white patients, with medians of 6.2 years and 5.7 years, respectively, but survival from the time of diagnosis was significantly longer among black individuals (median, 7.7 years vs 6.1 years; P = .03). Maintenance therapy was found to positively impact progression-free survival but not overall survival, irrespective of race. CONCLUSIONS: The results of the current study confirm ethnic differences in age, referral patterns, response to therapy, and overall survival. Future validation of these disparities is urgently needed.

α-Tubulin acetylation elevated in metastatic and basal-like breast cancer cells promotes microtentacle formation, adhesion, and invasive migration.

Metastatic cases of breast cancer pose the primary challenge in clinical management of this disease, demanding the identification of effective therapeutic strategies that remain wanting. In this study, we report that elevated levels of α-tubulin acetylation are a sufficient cause of metastatic potential in breast cancer. In suspended cell culture conditions, metastatic breast cancer cells exhibited high α-tubulin acetylation levels that extended along microtentacle (McTN) protrusions. Mutation of the acetylation site on α-tubulin and enzymatic modulation of this posttranslational modification exerted a significant impact on McTN frequency and the reattachment of suspended tumor cells. Reducing α-tubulin acetylation significantly inhibited migration but did not affect proliferation. In an analysis of more than 140 matched primary and metastatic tumors from patients, we found that acetylation was maintained and in many cases increased in lymph node metastases compared with primary tumors. Proteomic analysis of an independent cohort of more than 390 patient specimens further documented the relationship between increased α-tubulin acetylation and the aggressive behaviors of basal-like breast cancers, with a trend toward increased risk of disease progression and death in patients with high-intensity α-tubulin acetylation in primary tumors. Taken together, our results identify a tight correlation between acetylated α-tubulin levels and aggressive metastatic behavior in breast cancer, with potential implications for the definition of a simple prognostic biomarker in patients with breast cancer.

Emergence of HPV16-positive oropharyngeal cancer in Black patients over time: University of Maryland 1992-2007.

While we previously reported a striking racial difference in the prevalence of human papilloma virus (HPV)-positive squamous cell carcinoma of the oropharynx (OPSCC), less is known about differences in outcomes and trends over time in OPSCC by HPV status and race. We conducted a retrospective analysis of 467 patients with OPSCC treated at the University of Maryland Greenebaum Cancer Center (Baltimore, MD) between 1992 and 2007, of which 200 had tissue available for HPV16 testing. HPV16-positive patients were significantly more likely to be white, with 45.5% of whites and 15.5% of blacks testing positive for HPV16. There was a significant increase in HPV16-positive OPSCC for all patients over time from 15.6% in 1992 to 1995 to 43.3% in 2004 to 2007 (P = 0.01). From 1992 to 1995, 33% of white patients were HPV16-positive, with no black patients positive. From 2004 to 2007, 17.7% of black patients and 54% of white patients were HPV16-positive. White and black patients with HPV16-positive tumors had an identical and favorable overall survival (OS; median, 8.1 and 8.1 years, respectively). However, among HPV16-negative patients, whites had an improved OS compared with blacks (median, 2.3 vs. 0.9 years, respectively; P = 0.02), including when analyzed in a multivariable Cox regression model. From 1992 to 2007, the percentage of HPV16-positive OPSCC increased for white patients and was seen for the first time in black patients. While survival for HPV-positive black and white patients was similar and favorable, outcomes for HPV-negative patients were poor, with blacks having worse survival even after controlling for baseline characteristics.

HDAC inhibitor entinostat restores responsiveness of letrozole-resistant MCF-7Ca xenografts to aromatase inhibitors through modulation of Her-2.

We previously showed that in innately resistant tumors, silencing of the estrogen receptor (ER) could be reversed by treatment with a histone deacetylase (HDAC) inhibitor, entinostat. Tumors were then responsive to aromatase inhibitor (AI) letrozole. Here, we investigated whether ER in the acquired letrozole-resistant tumors could be restored with entinostat. Ovariectomized athymic mice were inoculated with MCF-7Ca cells, supplemented with androstenedione (Δ(4)A), the aromatizable substrate. When the tumors reached about 300 mm(3), the mice were treated with letrozole. After initial response to letrozole, the tumors eventually became resistant (doubled their initial volume). The mice then were grouped to receive letrozole, exemestane (250 µg/d), entinostat (50 µg/d), or the combination of entinostat with letrozole or exemestane for 26 weeks. The growth rates of tumors of mice treated with the combination of entinostat with letrozole or exemestane were significantly slower than with the single agent (P < 0.05). Analysis of the letrozole-resistant tumors showed entinostat increased ERα expression and aromatase activity but downregulated Her-2, p-Her-2, p-MAPK, and p-Akt. However, the mechanism of action of entinostat in reversing acquired resistance did not involve epigenetic silencing but rather included posttranslational as well as transcriptional modulation of Her-2. Entinostat treatment reduced the association of the Her-2 protein with HSP-90, possibly by reducing the stability of Her-2 protein. In addition, entinostat also reduced Her-2 mRNA levels and its stability. Our results suggest that the HDAC inhibitor may reverse letrozole resistance in cells and tumors by modulating Her-2 expression and activity.

Metformin prevents liver tumorigenesis by inhibiting pathways driving hepatic lipogenesis.

A number of factors have been identified that increase the risk of hepatocellular carcinoma (HCC). Recently it has become appreciated that type II diabetes increases the risk of developing HCC. This represents a patient population that can be identified and targeted for cancer prevention. The biguanide metformin is a first-line therapy for the treatment of type II diabetes in which it exerts its effects primarily on the liver. A role of metformin in HCC is suggested by studies linking metformin intake for control of diabetes with a reduced risk of HCC. Although a number of preclinical studies show the anticancer properties of metformin in a number of tissues, no studies have directly examined the effect of metformin on preventing carcinogenesis in the liver, one of its main sites of action. We show in these studies that metformin protected mice against chemically induced liver tumors. Interestingly, metformin did not increase AMPK activation, often shown to be a metformin target. Rather metformin decreased the expression of several lipogenic enzymes and lipogenesis. In addition, restoring lipogenic gene expression by ectopic expression of the lipogenic transcription factor SREBP1c rescues metformin-mediated growth inhibition. This mechanism of action suggests that metformin may also be useful for patients with other disorders associated with HCC in which increased lipid synthesis is observed. As a whole these studies show that metformin prevents HCC and that metformin should be evaluated as a preventive agent for HCC in readily identifiable at-risk patients.

Computer assisted quantitative immunofluorescence of tumor tissue marker expression and clinical outcome to chemotherapy in advanced breast cancer patients.

Chemotherapy is frequently used in the treatment of advanced breast cancer. The identification of patient-specific tumor characteristics that can improve the ability to predict response to chemotherapy would help optimize advanced breast cancer treatment approaches. Quantitative immunofluorescence (QIF) may be applied to the standardization of protein analysis, resulting in increased sensitivity and reproducibility. In the current pilot study, QIF was used to correlate the expression of beta tubulin III and thymidylate synthase with clinical outcome associated with taxane and capecitabine treatment, respectively. QIF analysis is based on fluorescent dye-labeled monoclonal antibody staining followed by computer-assisted microscopy to measure the expression of molecular markers in tumor samples derived from a retrospective database. The interpretation of the tumor marker expression levels results in classification of breast tumors as sensitive or resistant to a mechanistically related drug. Overall diagnostic accuracy of QIF for taxane based therapy was 88% (CI 75.0 - 95.3) with a positive predictive value of 86% and a negative predictive value of 100%, while diagnostic accuracy QIF for capecitabine therapy was 86% (CI 88.0-96.0) with a positive predictive value of 80% and a negative predictive value of 100%. In this study, QIF showed retrospectively a potential for predictive value when analyzing chemotherapeutic treatments for individual advanced stage breast cancer patients. The predictive power of the QIF for chemotherapy confirms that further studies utilizing larger clinical cohorts are warranted.

Combination of anastrozole with fulvestrant in the intratumoral aromatase xenograft model.

Although the aromatase inhibitor anastrozole has been shown to be very effective in the treatment of hormone-dependent postmenopausal breast cancer, some patients with advanced disease will develop resistance to treatment. To investigate therapeutic strategies to overcome resistance to anastrozole treatment, we have used an intratumoral aromatase model that simulates postmenopausal breast cancer patients with estrogen-dependent tumors. Growth of the tumors in the mice was inhibited by both anastrozole and fulvestrant compared with the control tumors. Nevertheless, tumors had doubled in size at 5 weeks of treatment. We therefore investigated whether switching the original treatments to anastrozole or fulvestrant alone or the combination of anastrozole plus fulvestrant would reduce tumor growth. The results showed that the best strategy to reverse the insensitivity to anastrozole or fulvestrant is to combine the two agents. Additionally, the tumors treated with anastrozole plus fulvestrant from the beginning had only just doubled their size after 14 weeks of treatment, whereas the anastrozole and fulvestrant treatments alone resulted in 9- and 12-fold increases in tumor size, respectively, in the same time period. Anastrozole plus fulvestrant from the beginning or in sequence was associated with down-regulation of signaling proteins involved in the development of hormonal resistance such as insulin-like growth factor type I receptor beta, mitogen-activated protein kinase (MAPK), p-MAPK, AKT, mammalian target of rapamycin (mTOR), p-mTOR, and estrogen receptor alpha compared with tumors treated with anastrozole or fulvestrant alone. These results suggest that blocking the estrogen receptor and aromatase may delay or reverse the development of resistance to aromatase inhibitors in advanced breast cancer patients.