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.

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.

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.

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.

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.

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.

Ionizing radiation induces delayed hyperrecombination in Mammalian cells.

Exposure to ionizing radiation can result in delayed effects that can be detected in the progeny of an irradiated cell multiple generations after the initial exposure. These effects are described under the rubric of radiation-induced genomic instability and encompass multiple genotoxic endpoints. We have developed a green fluorescence protein (GFP)-based assay and demonstrated that ionizing radiation induces genomic instability in human RKO-derived cells and in human hamster hybrid GM10115 cells, manifested as increased homologous recombination (HR). Up to 10% of cells cultured after irradiation produce mixed GFP(+/-) colonies indicative of delayed HR or, in the case of RKO-derived cells, mutation and deletion. Consistent with prior studies, delayed chromosomal instability correlated with delayed reproductive cell death. In contrast, cells displaying delayed HR showed no evidence of delayed reproductive cell death, and there was no correlation between delayed chromosomal instability and delayed HR, indicating that these forms of genome instability arise by distinct mechanisms. Because delayed hyperrecombination can be induced at doses of ionizing radiation that are not associated with significantly reduced cell viability, these data may have important implications for assessment of radiation risk and understanding the mechanisms of radiation carcinogenesis.

Activation of mitogen-activated protein kinase in xenografts and cells during prolonged treatment with aromatase inhibitor letrozole.

Ovariectomized mice bearing tumor xenografts grown from aromatase-transfected estrogen receptor (ER)-positive human breast cancer cells (MCF-7Ca) were injected s.c. with 10 microg/d letrozole for up to 56 weeks. Western blot analysis of the tumors revealed that ERs (ERalpha) were increased at 4 weeks but decreased at weeks 28 and 56. Expression of erbB-2 and p-Shc increased throughout treatment, whereas growth factor receptor binding protein 2 (Grb2) increased only in tumors proliferating on letrozole (weeks 28 and 56). In cells isolated from tumors after 56 weeks and maintained as a cell line (LTLT-Ca) in 1 micromol/L letrozole, ERalpha was also decreased whereas erbB-2, adapter proteins (p-Shc and Grb2), and the signaling proteins in the mitogen-activated protein kinase (MAPK) cascade were increased compared with MCF-7Ca cells. Growth was inhibited in LTLT-Ca cells but not in MCF-7Ca cells treated with MAPK kinase 1/2 inhibitors U0126, and PD98059 (IC(50) approximately 25 micromol/L). PD98059 (5 micromol/L) also reduced MAPK activity and increased ERalpha to the levels in MCF-7Ca cells. Epidermal growth factor receptor kinase inhibitor, gefitinib (ZD1839) inhibited growth of LTLT-Ca cells (IC(50) approximately 10 micromol/L) and restored their sensitivity to tamoxifen and anastrozole. In xenografts, combined treatment with ER down-regulator fulvestrant and letrozole, prevented increases in erbB-2 and activation of MAPK and was highly effective in inhibiting tumor growth throughout 29 weeks of treatment. These results indicate that blocking both ER- and growth factor-mediated transcription resulted in the most effective inhibition of growth of ER-positive breast cancer cells.

Additive antitumor effect of aromatase inhibitor letrozole and antiestrogen fulvestrant in a postmenopausal breast cancer model.

Blocking estrogen receptors with antiestrogens and blocking estrogen synthesis with aromatase inhibitors are two strategies currently being used for reducing the effect of estrogen in postmenopausal estrogen receptor-positive breast cancer patients. To optimize these treatment strategies, we have investigated whether tumor progression can be delayed by combining the pure antiestrogen fulvestrant with the nonsteroidal aromatase inhibitor letrozole. These studies were done in ovariectomized, athymic mice bearing tumors of estrogen receptor-positive human breast cancer cells stably transfected with the aromatase gene (MCF-7Ca). Groups of mice with equivalent tumor volumes were injected s.c. daily with vehicle (control; n = 6), fulvestrant (1 mg/d; n = 7), letrozole (10 microg/d; n = 18), or letrozole (10 microg/d) plus fulvestrant (1 mg/d; n = 5). All treatments were effective in suppressing tumor growth compared with controls (P < 0.001). Tumor volumes of the fulvestrant-treated group had doubled in 10 weeks. After 19 weeks of letrozole (10 microg/d) treatment when tumors had nearly doubled in volume, mice (n = 18) were assigned to second-line therapy with letrozole (100 microg/d; n = 6), tamoxifen (100 microg/d; n = 6), or remained on letrozole treatment (10 microg/d; n = 6). However, tumors continued to increase in volume in these groups. Tumors of animals treated with the combination of letrozole plus Faslodex regressed over 29 weeks of treatment by 45%. Thus, the combination of letrozole plus fulvestrant was more effective in suppressing tumor growth than either letrozole or fulvestrant alone or sequential therapies with tamoxifen or a higher dose of letrozole (100 microg/d).

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.

Mitochondrial DNA content increase in response to cigarette smoking.

An increase in mitochondrial DNA (mtDNA) content and decline in mitochondrial function occurs with aging and in response to DNA-damaging agents, including tobacco smoke. We did a cross-sectional study and quantified changes in mtDNA content in a population of individuals with varied smoking and alcohol exposure. Age, smoking history, ethanol intake, and other demographic data were characterized for 604 individuals participating in a screening study for smoking-related upper aerodigestive malignancy. Total DNA was extracted from exfoliated cells in saliva. DNA from a nuclear gene, beta-actin, and two mitochondrial genes, cytochrome c oxidase I and II (Cox I and Cox II), were quantified by real-time PCR. mtDNA content was correlated with age, exposure history, and other variables using multivariate regression analyses. A significant increase (P<0.001) in mtDNA content was noted in smokers (31% and 29% increase for Cox I and Cox II, respectively) and former smokers (31% and 34%) when compared with never smokers. This association persisted after adjustment for other significant factors including age, alcohol drinking, and income (P<0.001). Increased mtDNA content was positively associated with pack-years of smoking (P=0.02). Despite an average smoking cessation interval of 21 years in former smokers, tobacco cessation interval was not statistically significantly associated with mtDNA content. Smoking is associated with increased mtDNA content in a dose-dependent fashion. Mitochondrial DNA alterations in response to smoking persist for several decades after smoking cessation, consistent with long-term, smoking-related damage.

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.

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.

Effects of exemestane and tamoxifen in a postmenopausal breast cancer model.

PURPOSE: To optimize treatment strategies for postmenopausal breast cancer patients, we investigated the efficacy of the steroidal aromatase inhibitor exemestane alone or in combination with the antiestrogen tamoxifen in a xenograft model of postmenopausal breast cancer. We also determined the effects of these agents in sequential second-line therapy and the effect of the nonsteroidal aromatase inhibitor letrozole on tumors that progressed on the above treatments. EXPERIMENTAL: Aromatase-transfected human estrogen receptor-positive breast cancer cells (MCF-7Ca) were grown as tumors in ovariectomized athymic mice. Animals received subcutaneous injection with vehicle, tamoxifen, exemestane, tamoxifen plus exemestane, and letrozole. Tumor volumes were measured weekly. RESULTS: All treatments were effective initially in suppressing tumor growth as first-line therapy compared with vehicle treatment. Exemestane suppressed tumor growth to a greater extent than tamoxifen. However, the combination of tamoxifen plus exemestane was more effective than either drug alone. After tumor volumes doubled on initial treatment, the mice were crossed over to receive exemestane or tamoxifen. Tumor growth slowed briefly in mice treated with tamoxifen and crossed over to exemestane, but tumor growth continued unabated in those changed from exemestane to tamoxifen. However, letrozole was effective in both groups as third-line therapy for a limited period. Letrozole as initial single agent was the best overall treatment in terms of the degree of tumor suppression and the length of effectiveness of treatment. CONCLUSION: Exemestane was more effective in controlling tumor growth than tamoxifen. In addition, the combination of exemestane plus tamoxifen was clearly more effective than sequential use of these agents in the tumor model. However, the nonsteroidal aromatase inhibitor letrozole as first-line therapy was overall the most effective treatment in controlling tumor growth.

Phase I clinical trial of the inosine monophosphate dehydrogenase inhibitor mycophenolate mofetil (cellcept) in advanced multiple myeloma patients.

PURPOSE: Inosine monophosphate dehydrogenase (IMPDH) inhibitors have been used to induce leukemia blast cell differentiation but have not been tested in multiple myeloma for activity. Currently, available IMPDH inhibitor, mycophenolate mofetil (MMF), which is known as an immunosuppressant, was shown to induce apoptosis in myeloma cell lines. On the basis of our preclinical studies, we designed a clinical study to test our hypothesis that MMF has antimyeloma activity. EXPERIMENTAL DESIGN: A Phase I MMF dose escalation study was conducted in relapsed and refractory myeloma patients who had documented disease progression by myeloma markers or bone marrow plasmacytosis to determine the maximum tolerated dose, toxicities, and efficacy of the drug. To assess the activity of IMPDH inhibition in the myeloma cells of patients, we measured intracellular nucleotide triphosphate levels by high-performance liquid chromatography-based analysis and examined the correlation with clinical response. RESULTS: Among the 11 study patients, MMF was generally well tolerated and was administered up to a maximum dose of 5 g/day. The most common toxicity was grade 1 fatigue (n = 4, 36%). One patient had a partial response (3 g/day), four patients had stable disease, and six patients had progression of disease. There was a statistically significant difference in the intracellular dGTP level changes between the stable disease/partial response group versus progression of disease. CONCLUSIONS: MMF at 1 to 5 g/day daily dose is well tolerated by patients with relapsed and refractory multiple myeloma patients. Positive correlation between clinical response and depletion of intracellular dGTP level was shown. Future drug development to target this enzyme maybe useful in treating myelomas.

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.