Ethnic differences in drug metabolism and toxicity from chemotherapy

Validation of the CancerMath prognostic tool for breast cancer in Southeast Asia

BACKGROUND

CancerMath is a set of web-based prognostic tools which predict nodal status and survival up to 15 years after diagnosis of breast cancer. This study validated its performance in a Southeast Asian setting.

METHODS

Using Singapore Malaysia Hospital-Based Breast Cancer Registry, clinical information was retrieved from 7064 stage I to III breast cancer patients who were diagnosed between 1990 and 2011 and underwent surgery. Predicted and observed probabilities of positive nodes and survival were compared for each subgroup. Calibration was assessed by plotting observed value against predicted value for each decile of the predicted value. Discrimination was evaluated by area under a receiver operating characteristic curve (AUC) with 95 % confidence interval (CI).

RESULTS

The median predicted probability of positive lymph nodes is 40.6 % which was lower than the observed 43.6 % (95 % CI, 42.5 %-44.8 %). The calibration plot showed underestimation for most of the groups. The AUC was 0.71 (95 % CI, 0.70-0.72). Cancermath predicted and observed overall survival probabilities were 87.3 % vs 83.4 % at 5 years after diagnosis and 75.3 % vs 70.4 % at 10 years after diagnosis. The difference was smaller for patients from Singapore, patients diagnosed more recently and patients with favorable tumor characteristics. Calibration plot also illustrated overprediction of survival for patients with poor prognosis. The AUC for 5-year and 10-year overall survival was 0.77 (95 % CI: 0.75-0.79) and 0.74 (95 % CI: 0.71-0.76).

CONCLUSIONS

The discrimination and calibration of CancerMath were modest. The results suggest that clinical application of CancerMath should be limited to patients with better prognostic profile.

Racial Differences Among Factors Associated with Participation in Clinical Research Trials

OBJECTIVE

To identify whether racial differences exist among various factors associated with patients' decision to participate in clinical research trials.

METHODS

A self-administered, IRB-approved survey was utilized with inclusion criteria requiring subjects to be 18 years of age or older, having active patient status and ability to complete the survey without assistance. Subjects were asked to rate potential influential motivators, barriers, and facilitators on a "no influence" (0) to "most influence" (4) scale for participation in research that tests a new drug or device. Kruskal-Wallis testing was used to identify factors significantly associated with race.

RESULTS

Analysis included 1643 surveys: 949 (57.8 %) Caucasian; 217 (13.2 %) African-American; 317 (19.3 %) Hispanic; 62 (3.8 %) Multiracial; and 98 (6.0 %) "Other" minorities. Statistically significant differences (p ≤ .02) by race were found for five out of ten motivating factors. "How well the research study is explained to me" had the highest mean value for all races except other minorities, for whom "Knowledge learned from my participation will benefit someone in the future" scored highest. "Risk of unknown side-effects" was the greatest barrier for all races.

CONCLUSION

Racial differences exist not only between Caucasians and Minorities for the factors associated with their clinical trial participation, but also among different minority races themselves. To promote diversity in research, recruitment strategies for each individual race should be customized based on what matters to the target population.

Influx transporter variants as predictors of cancer chemotherapy-induced toxicity: systematic review and meta-analysis

AIM

Chemotherapeutic agents have been shown to increase lung patient survival, however their use may be limited by their serious adverse effects. We aimed to assess int impact of pharmacogenetic variation of influx transporters on inter-individual patient variation in adverse drug reactions.

PATIENTS & METHODS

We conducted a meta-analysis and systemic review and identified 16 publications, totaling 1510 patients, to be eligible for review.

RESULTS

Meta-analysis showed east-Asian patients expressing SLCO1B1 521T>C or 1118G>A to have a two- to fourfold increased risk of irinotecan-induced neutropenia but not diarrhea. American patients, expressing SLC19A1 IVS2(4935) G>A, were further associated with pemetrexed/gemcitabine-induced grade 3+ leukopenia.

CONCLUSION

Future studies should look to robust validation of SLCO1B1 and SLC19A1 as prognostic markers in the management of lung cancer patients.

Early initiation of chemotherapy following complete resection of advanced ovarian cancer associated with improved survival: NRG Oncology/Gynecologic Oncology Group study

BACKGROUND

To determine whether time from surgery to initiation of chemotherapy impacts survival in advanced ovarian carcinoma.

PATIENTS AND METHODS

This is a post-trial ad hoc analysis of Gynecologic Oncology Group protocol 218, a phase III randomized, double-blind, placebo-controlled trial designed to study the antiangiogenesis agent, bevacizumab, in primary and maintenance therapy for patients with newly diagnosed advanced ovarian carcinoma. Maximum attempt at debulking was an eligibility criterion. Stage III patients, not stage IV, were required to have gross macroscopic or palpable residual disease following surgery. The survival impact of time from surgery to initiation of chemotherapy was studied using Cox regression models and stratified by treatment arm, residual disease and other clinical and pathologic factors.

RESULTS

One thousand seven hundred eighteen assessable patients were randomized (stage III (n = 1237); stage IV (n = 477), including those with complete resection (stage IV only, n = 81), low-volume residual (≤1 cm, n = 701), and suboptimal (>1 cm, n = 932). On multivariate analysis, time to chemotherapy initiation was predictive of overall survival (P < 0.001), with the complete resection group (i.e. stage IV) encountering an increased risk of death when time to initiation of chemotherapy exceeded 25 days (95% confidence interval 16.6-49.9 days).

CONCLUSION

Survival for women with advanced ovarian cancer may be adversely affected when initiation of chemotherapy occurs >25 days following surgery. Our analysis applies to stage IV only as women with stage III who underwent complete resection were not eligible for this trial. These results, however, are consistent with Gompertzian first-order kinetics where patients with microscopic residual are most vulnerable.

CLINICAL TRIALS IDENTIFIER

NCT00262847.

The effects of common medications on volumetric phallometry

Phallometry is a physiological measure of sexual response widely used for the assessment of paedophilia among sexual offenders. Although many medications decrease penile response sufficiently to interfere with sexual intercourse, it is unknown to what extent such medications might interfere with phallometric testing. In the current study, we utilized a naturalistic convenience sample of 1078 men who attended a clinic for assessment of sexual preferences, mostly related to sexual offence convictions. In the present analyses, we quantified the differences in penile response during phallometric assessment associated with taking a range of common medications. Participants on medication typically showed less penile output than participants not taking medications; however, differences were largely accounted for by age rather than by medication status. Though most medications were associated with decreases in penile responsivity during volumetric phallometric testing, such changes were small in absolute terms and appeared to be associated with ageing rather than with the medications themselves.

Perceived Stress Levels, Chemotherapy, Radiation Treatment and Tumor Characteristics Are Associated with a Persistent Increased Frequency of Somatic Chromosomal Instability in Women Diagnosed with Breast Cancer: A One Year Longitudinal Study

While advances in therapeutic approaches have resulted in improved survival rates for women diagnosed with breast cancer, subsets of these survivors develop persistent psychoneurological symptoms (fatigue, depression/anxiety, cognitive dysfunction) that compromise their quality of life. The biological basis for these persistent symptoms is unclear, but could reflect the acquisition of soma-wide chromosomal instability following the multiple biological/psychological exposures associated with the diagnosis/treatment of breast cancer. An essential first step toward testing this hypothesis is to determine if these cancer-related exposures are indeed associated with somatic chromosomal instability frequencies. Towards this end, we longitudinally studied 71 women (ages 23-71) with early-stage breast cancer and quantified their somatic chromosomal instability levels using a cytokinesis-blocked micronuclear/cytome assay at 4 timepoints: before chemotherapy (baseline); four weeks after chemotherapy initiation; six months after chemotherapy (at which time some women received radiotherapy); and one year following chemotherapy initiation. Overall, a significant change in instability frequencies was observed over time, with this change differing based on whether the women received radiotherapy (p=0.0052). Also, significantly higher instability values were observed one year after treatment initiation compared to baseline for the women who received: sequential taxotere/doxorubicin/cyclophosphamide (p<0.001) or taxotere/cyclophosphamide (p=0.014). Significant predictive associations for acquired micronuclear/cytome abnormality frequencies were also observed for race (p=0.0052), tumor type [luminal B tumors] (p=0.0053), and perceived stress levels (p=0.0129). The impact of perceived stress on micronuclear/cytome frequencies was detected across all visits, with the highest levels of stress being reported at baseline (p =0.0024). These findings suggest that the cancer-related exposome has an impact on both healthy somatic cells and tumor cells, and may lead to persistent chromosomal instability. In addition, stress was a significant predictor of chromosomal instability; thus, interventions that aim to reduce stress may reduce acquired soma-wide chromosomal instability for cancer survivors.

Survival differences of Asian and Caucasian epithelial ovarian cancer patients in the United States

OBJECTIVE

To compare the racial differences in treatment and survival of Asian-Americans and White patients with epithelial ovarian cancer.

METHODS

Data were obtained from the Surveillance, Epidemiology, and End Results Program between 1988 and 2009 and analyzed using Chi-squared tests, Kaplan-Meier methods, and Cox regression analysis.

RESULTS

Of the 52,260 women, 3932 (7.5%) were coded as Asian, and 48,328 (92.5%) were White. The median age of Asians at diagnosis was 56 vs. 64 years for the Whites (p<0.001). Asians were more likely to undergo primary surgery, have an earlier stage of disease, have a diagnosis of a non-serous histology, and have lower grade tumors. The 5-year disease-specific survival (DSS) of Asians was higher compared to Whites (59.1% vs. 47.3%, p<0.001). On a subset analysis, Vietnamese, Filipino, Chinese, Korean, Japanese, and Asian Indian/Pakistani ethnicities had 5-year DSS of 62.1%, 61.5%, 61.0%, 59.0%, 54.6%, and 48.2%, respectively (p=0.015). On multivariate analysis, age at diagnosis, year of diagnosis, race, surgery, stage, and tumor grade were all independent prognostic factors for survival. Asians were further stratified to U.S. born versus those who were born in Asia and immigrated. Asian immigrants presented at a younger age compared to U.S. born Asians. Immigrants were found to have an improved 5-year DSS when compared to U.S. born Asians and Whites of 55%, 52%, and 48%, respectively (p<0.001).

CONCLUSION

Asians were more likely to be younger, undergo primary surgery, have an earlier stage of disease, non-serous histology, lower grade tumors, and higher survival.

The Outcome of Patients with Triple Negative Breast Cancer: The Turkish Oncology Group Experience

OBJECTIVE

Triple negative breast cancer (TNBC) is generally considered as a poorer prognostic subgroup, with propensity for earlier relapse and visceral involvement. The aim of this study is to evaluate the outcome of non-metastatic TNBC patients from different centers in Turkey and identify clinical and pathologic variables that may effect survival.

MATERIALS AND METHODS

Between 1993-2007, from five different centers in Turkey, 316 nonmetastatic triple negative breast cancer patients were identified with follow-up of at least 12 months. The data was collected retrospectively from patient charts. The prognostic impact of several clinical variables were evaluated by the Kaplan-Meier and Cox multivariate anayses.

RESULTS

Mean age at diagnosis was 49 years (range: 24-82). The majority of the patient group had invasive ductal carcinoma (n: 260, 82.3%) and stage II disease (n: 164; 51.9%). Majority of the patients (87.7%) received adjuvant chemotherapy. 5 year overall survival (OS) and disease-free survival (DFS) rates were 84.6% and 71.6%, respectively. Univariate analysis revealed locally advanced disease (p: 0.001), advanced pathological stage (p: 0.021), larger tumor size (T1&T2 vs T3&T4) (p<0.001), nodal positivity (p: 0.006), and extensive nodal involvement (p<0.001) as significant factors for DFS; whereas, advanced pathological stage (p: 0.017), extensive nodal involvement (p<0.001) and larger tumor size (p: 0,001) and presence of breast cancer-affected member in the family (p=0.05) were identified as prognostic factors with an impact on OS. Multivariate analysis revealed larger tumor size (T3&T4 vs T1&T2) and presence of lymph node metastases (node-positive vs node-negative) as significant independent prognostic factors for DFS (Hazard ratio (HR): 3.03, 95% CI: 1.71-5.35, p<0.001 and HR: 1.77, 95% CI: 1.05-3.0, p=0.03, respectively). Higher tumor stage was the only independent factor affecting overall survival (HR: 2.81; 95% CI, 1.27-6.22, p=0.01).

CONCLUSION

The outcome of patients with TNBC in this cohort is comparable to other studies including TNBC patients. Tumor size and presence of lymph node metastasis are the major independent factors that have effect on DFS, however higher tumor stage was the only negative prognostic factor for OS.

Increased genetic diversity of ADME genes in African Americans compared with their putative ancestral source populations and implications for pharmacogenomics

BACKGROUND

African Americans have been treated as a representative population for African ancestry for many purposes, including pharmacogenomic studies. However, the contribution of European ancestry is expected to result in considerable differences in the genetic architecture of African American individuals compared with an African genome. In particular, the genetic admixture influences the genomic diversity of drug metabolism-related genes, and may cause high heterogeneity of drug responses in admixed populations such as African Americans.

RESULTS

The genomic ancestry information of African-American (ASW) samples was obtained from data of the 1000 Genomes Project, and local ancestral components were also extracted for 32 core genes and 252 extended genes, which are associated with drug absorption, distribution, metabolism, and excretion (ADME) genes. As expected, the global genetic diversity pattern in ASW was determined by the contributions of its putative ancestral source populations, and the whole profiles of ADME genes in ASW are much closer to those in YRI than in CEU. However, we observed much higher diversity in some functionally important ADME genes in ASW than either CEU or YRI, which could be a result of either genetic drift or natural selection, and we identified some signatures of the latter. We analyzed the clinically relevant polymorphic alleles and haplotypes, and found that 28 functional mutations (including 3 missense, 3 splice, and 22 regulator sites) exhibited significantly higher differentiation between the three populations.

CONCLUSIONS

Analysis of the genetic diversity of ADME genes showed differentiation between admixed population and its ancestral source populations. In particular, the different genetic diversity between ASW and YRI indicated that the ethnic differences in pharmacogenomic studies are broadly existed despite that African ancestry is dominant in Africans Americans. This study should advance our understanding of the genetic basis of the drug response heterogeneity between populations, especially in the case of population admixture, and have significant implications for evaluating potential inter-population heterogeneity in drug treatment effects.

The role of drug metabolizing enzymes in clearance

INTRODUCTION

Metabolism is one of the most important clearance pathways representing the major clearance route of 75% drugs. The four most common drug metabolizing enzymes (DME) that contribute significantly to elimination pathways of new chemical entities are cytochrome P450s, UDP-glucuronosyltransferases, aldehyde oxidase and sulfotransferases. Accurate prediction of human in vivo clearance by these enzymes, using both in vitro and in vivo tools, is critical for the success of drug candidates in human translation.

AREAS COVERED

Important recent advances of key DME are reviewed and highlighted in the following areas: major isoforms, tissue distribution, generic polymorphism, substrate specificity, species differences, mechanism of catalysis, in vitro-in vivo extrapolation and the importance of using optimal assay conditions and relevant animal models.

EXPERT OPINION

Understanding the clearance mechanism of a compound is the first step toward successful prediction of human clearance. It is critical to apply appropriate in vitro and in vivo methodologies and physiologically based models in human translation. While high-confidence prediction for P450-mediated clearance has been achieved, the accuracy of human clearance prediction is significantly lower for other enzyme classes. More accurate predictive methods and models are being developed to address these challenges.

Safety and tolerability of inhalational anticholinergics in COPD

Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality. With the significant toll of the disease, more resources have been invested in developing new treatment modalities. Among these medications, inhalational anticholinergics are widely used for the management of stable COPD. The newer agents, with longer half-lives and better safety profiles, have emerged and helped to improve management of COPD patients. The available data from randomized clinical trials support use of these agents. Multiple randomized clinical trials show safety and efficacy of the newer long-acting inhaled anticholinergics, including tiotropium and aclidinium. A recent meta-analysis of tiotropium delivered with Respimat(®) raised some safety concerns. A large trial, comparing different doses and delivery methods of inhaled tiotropium, is ongoing to determine the effect on mortality. As clinical trials may not comprehensively represent the entire COPD population, caution should be exercised when these agents are used in higher-risk populations, like individuals with cardiac arrhythmias or urinary obstruction. In this publication, we review the safety of inhalational anticholinergics.

Outcome of childhood acute Lymphoblastic leukemia in Egyptian children: a challenge for limited health resource countries

In childhood acute lymphoblastic leukemia (ALL) the reported 5-year event-free survival (EFS) rates are as high as 80%. Since 2004, multiple Egyptian centers shifted protocol of therapy of ALL to the CCG 1991 (the single delayed intensification arm) and CCG 1961 protocol for standard risk and high-risk ALL therapy, respectively, being cost effective. We aimed to evaluate the efficacy and safety of the CCG protocol in treatment of childhood ALL in Ain Shams and Menoufeya University hospitals.

METHODS

Fifty-two ALL patients, aged 1-17 years, treated according to the modified CCG protocol in both centers and registered from November 2004 to December 2005 were included. They were classified into three risk groups, standard risk (SR), high-risk standard arm (HR-SA), and high-risk augmented arm (HR-AA).

RESULTS

The mean age at diagnosis was 5.9 + 3.3 years, male/female ratio of 1.6:1, and central nervous system leukemia represented 6%. The 5-year overall survival (OS) and EFS were 84.6% and 67%, respectively. The 5-year OS and EFS were 92.6% and 70% in SR, 68.8% and 55% in HR-SA, 88.9% and 80% in HR-AA patients, respectively. Six patients had grade 3-4 adverse events.

CONCLUSION

The outcome of HR-SA protocol was inferior to the other two groups, necessitating shift to a more intensified arm with double delayed intensification. The use of minimal residual disease for better risk classification of childhood ALL is recommended in our centers.

Dialogues on diversifying clinical trials: successful strategies for engaging women and minorities in clinical trials

There is mounting scientific evidence pointing to genetic or physiologic distinctions between genders and among racial and ethnic groups that influence disease risk and severity and response to treatment. The diverse enrollment of subjects engaged in clinical trials research is, thus, critical to developing safer and more effective drugs and medical devices. However, in the United States, there are striking disparities in clinical trial participation. To address this problem, the Food and Drug Administration (FDA) Office of Women's Health and the Society for Women's Health Research (SWHR) together convened the 2-day meeting, Dialogues on Diversifying Clinical Trials. The conference was held in Washington, DC, on September 22-23, 2011, and brought together a wide range of speakers from clinical research, industry, and regulatory agencies. Here, we present the major findings discussed at this meeting about female and minority patients and physicians and their willingness to participate in clinical trials and the barriers that sponsors face in recruiting a diverse trial population. We also discuss some recommendations for improving trial diversity through new technologies and greater efficiency in trial regulation and review.

Problems with the collection and interpretation of Asian-American health data: omission, aggregation, and extrapolation

Asian-American citizens are the fastest growing racial/ethnic group in the United States. Nevertheless, data on Asian American health are scarce, and many health disparities for this population remain unknown. Much of our knowledge of Asian American health has been determined by studies in which investigators have either grouped Asian-American subjects together or examined one subgroup alone (e.g., Asian Indian, Chinese, Filipino, Japanese, Korean, Vietnamese). National health surveys that collect information on Asian-American race/ethnicity frequently omit this population in research reports. When national health data are reported for Asian-American subjects, it is often reported for the aggregated group. This aggregation may mask differences between Asian-American subgroups. When health data are reported by Asian American subgroup, it is generally reported for one subgroup alone. In the Ni-Hon-San study, investigators examined cardiovascular disease in Japanese men living in Japan (Nippon; Ni), Honolulu, Hawaii (Hon), and San Francisco, CA (San). The findings from this study are often incorrectly extrapolated to other Asian-American subgroups. Recommendations to correct the errors associated with omission, aggregation, and extrapolation include: oversampling of Asian Americans, collection and reporting of race/ethnicity data by Asian-American subgroup, and acknowledgement of significant heterogeneity among Asian American subgroups when interpreting data.

Safety and tolerability of AZD8055 in Japanese patients with advanced solid tumors; a dose-finding phase I study

BACKGROUND

This is the first phase I, dose-finding study of AZD8055, a first-in-class dual mTORC1/2 inhibitor, in Japanese patients with advanced solid tumors.

PATIENTS AND METHODS

Patients received a single oral dose of AZD8055, followed by twice-daily (BID) dosing. The starting dose was 10 mg with dose escalations in subsequent cohorts to a maximum of 90 mg BID or a non-tolerated dose.

RESULTS

Seventeen patients were dosed: 10 mg (n=3), 40 mg (n=4), 60 mg (n=3), 90 mg (n=7). In the 90 mg cohort, one dose limiting toxicity (n=1) of increased aspartate aminotransferase and increased alanine aminotransferase was observed in the 90 mg BID cohort (n=1). Four patients, all in the 90 mg BID cohort, experienced a serious adverse event considered to be related to AZD8055: increased alanine aminotransferase (n=3), increased aspartate aminotransferase (n=3), increased gamma-glutamyltransferase (n=2). The 90 mg BID dose was considered as tolerated in Japanese patients but higher doses were not investigated as this dose was also the maximum tolerated dose in Western patients. AZD8055 was rapidly absorbed with greater-than-proportional increases in exposure with increasing dose. No responses were reported, but two patients had stable disease. Mean pAKT and p4EBP1 levels decreased in most cohorts. Conclusion The tolerability and pharmacokinetic profiles of AZD8055 in Japanese patients were similar to those reported in Western patients.

Significance of docetaxel-based chemotherapy as treatment for metastatic castration-resistant prostate cancer in Japanese men over 75 years old

OBJECTIVES

The objective of this study was to evaluate the significance of docetaxel-based chemotherapy in elderly Japanese men with metastatic castration-resistant prostate cancer (CRPC).

MATERIALS AND METHODS

This study included a total of 159 consecutive patients aged≥75 years with mCRPC who were treated with docetaxel-based chemotherapy. The efficacy and tolerability of this therapy were retrospectively analyzed.

RESULTS

In these 159 patients, the median age and prostate-specific antigen (PSA) level before docetaxel-based chemotherapy were 78 years and 44.0 ng/ml, respectively. Of these patients, 42 (26.4%) and 117 (73.6%) received docetaxel as a weekly (30 mg/m2) and 3-weekly (70 mg/m2) regimen, respectively, and estramustine was administered combining with docetaxel in 77 (48.4%). Following docetaxel-based chemotherapy, PSA declined in 118 patients (74.3%), including 87 (54.6%) achieving a PSA decline≥50%, and the median progression-free survival and overall survival (OS) were 2.9 and 23.2 months, respectively. Of several factors examined, univariate analysis identified performance status (PS), significant clinical pain, bone metastasis, schedule of treatment, treatment cycle, and PSA response as significant predictors of OS, of which only PS, treatment cycle, and PSA response appeared to be independently associated with OS on multivariate analysis. The major grade 3-4 toxicities were myelosuppression, including neutropenia, anemia, and thrombocytopenia in 78 (49.1%), 22 (13.8%), and 14 (8.8%), respectively.

CONCLUSIONS

These findings suggest that docetaxel-based chemotherapy is clinically feasible in Japanese men aged≥75 years with mCRPC considering the cancer control as well as safety associated with this therapy.

The database of chromosome imbalance regions and genes resided in lung cancer from Asian and Caucasian identified by array-comparative genomic hybridization

BACKGROUND

Cancer-related genes show racial differences. Therefore, identification and characterization of DNA copy number alteration regions in different racial groups helps to dissect the mechanism of tumorigenesis.

METHODS

Array-comparative genomic hybridization (array-CGH) was analyzed for DNA copy number profile in 40 Asian and 20 Caucasian lung cancer patients. Three methods including MetaCore analysis for disease and pathway correlations, concordance analysis between array-CGH database and the expression array database, and literature search for copy number variation genes were performed to select novel lung cancer candidate genes. Four candidate oncogenes were validated for DNA copy number and mRNA and protein expression by quantitative polymerase chain reaction (qPCR), chromogenic in situ hybridization (CISH), reverse transcriptase-qPCR (RT-qPCR), and immunohistochemistry (IHC) in more patients.

RESULTS

We identified 20 chromosomal imbalance regions harboring 459 genes for Caucasian and 17 regions containing 476 genes for Asian lung cancer patients. Seven common chromosomal imbalance regions harboring 117 genes, included gain on 3p13-14, 6p22.1, 9q21.13, 13q14.1, and 17p13.3; and loss on 3p22.2-22.3 and 13q13.3 were found both in Asian and Caucasian patients. Gene validation for four genes including ARHGAP19 (10q24.1) functioning in Rho activity control, FRAT2 (10q24.1) involved in Wnt signaling, PAFAH1B1 (17p13.3) functioning in motility control, and ZNF322A (6p22.1) involved in MAPK signaling was performed using qPCR and RT-qPCR. Mean gene dosage and mRNA expression level of the four candidate genes in tumor tissues were significantly higher than the corresponding normal tissues (P<0.001~P=0.06). In addition, CISH analysis of patients indicated that copy number amplification indeed occurred for ARHGAP19 and ZNF322A genes in lung cancer patients. IHC analysis of paraffin blocks from Asian Caucasian patients demonstrated that the frequency of PAFAH1B1 protein overexpression was 68% in Asian and 70% in Caucasian.

CONCLUSIONS

Our study provides an invaluable database revealing common and differential imbalance regions at specific chromosomes among Asian and Caucasian lung cancer patients. Four validation methods confirmed our database, which would help in further studies on the mechanism of lung tumorigenesis.

Rhabdomyosarcoma treatment and outcome at a multidisciplinary pediatric cancer center in Lebanon

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children. Outcome of patients treated on standard protocols, in a multidisciplinary cancer center setting outside of clinical trials, is not well reported. We reviewed characteristics and outcome of 23 pediatric patients treated at a single, multidisciplinary cancer center in Lebanon, between April 2002 and December 2010. Median follow-up was 41 months. The most commonly affected primary site was the head and neck (48%, n = 11). Nineteen tumors (82.6%) were of embryonal histology. Tumor size was ≥5 cm in eight (34.8%) patients. Sixteen patients (69.6%) had localized disease, and one (4.4%) had metastatic disease. Fifteen (65.2%) had Group III tumors. All patients received chemotherapy, for a duration ranging 21-51 weeks. Upfront surgical resection was performed in 10 patients (43.5%). Eighteen patients (78.3%) received radiation therapy. The 5-year overall and disease-free survival rates were 83% and 64%, respectively. Relapse correlated with absence of surgery. Treatment of childhood RMS in a multidisciplinary cancer center in Lebanon results in similar survival to that in developed countries when similar protocols are applied. There was a higher incidence of local relapse, but those were salvageable with further therapy and surgical local control.

First report of the safety, tolerability, and pharmacokinetics of the Src kinase inhibitor saracatinib (AZD0530) in Japanese patients with advanced solid tumours

BACKGROUND

Saracatinib (AZD0530) is a selective, oral Src inhibitor that has demonstrated antitumour activity in preclinical studies.

METHODS

This open-label, dose-escalation, phase I study evaluated the safety and tolerability of saracatinib in Japanese patients with advanced solid tumours (clinicaltrials.gov NCT00704366). Patients received continuous once-daily oral dosing with saracatinib starting 7 days after a single dose in ascending dose cohorts until dose-limiting toxicity (DLT) or disease progression. Pharmacokinetics and efficacy were also evaluated.

RESULTS

A total of 12 patients received saracatinib at doses of 50 (n = 3), 125 (n = 6), and 175 mg (n = 3). Median durations of exposure were 65, 44, and 16 days in the 50, 125, and 175 mg cohorts, respectively. The most common adverse events were diarrhoea (67 %), nausea (67 %), decreased appetite (58 %), lymphopenia (50 %) and pyrexia (50 %). The most common grade ≥3 adverse events were leukopenia, lymphopenia, neutropenia, and haemoglobin decreased (all 17 %). DLTs occurred in two patients, both in the 175 mg cohort: grade 3 aspartate aminotransferase increased with grade 3 gamma-glutamyltransferase increased (n = 1); and grade 3 hypoxia (n = 1). Following a single dose, saracatinib median t(max) across the doses was 2-4 h, and thereafter plasma concentrations declined in a biphasic manner, with mean terminal half-life of approximately 45 h. Geometric mean saracatinib exposures were 0.8-2.1 times greater than those reported in Caucasian patients. The best response was stable disease (50 mg, n = 2; 125 mg, n = 1).

CONCLUSIONS

Saracatinib was tolerated in Japanese patients with advanced solid tumours at doses up to 125 mg.

Ethnic difference in hematological toxicity in patients with non-small cell lung cancer treated with chemotherapy: a pooled analysis on Asian versus non-Asian in phase II and III clinical trials

INTRODUCTION

There are a large number of global clinical trials ongoing for patients with non-small cell lung cancer (NSCLC). Ethnic difference in toxicity has not been adequately studied.

METHODS

We performed a systematic search in PubMed for randomized phase II and III trials of NSCLC from January 2000 to December 2009, examining ethnic difference in hematological toxicity due to cytotoxic chemotherapy. Ethnicity was classified into Asian and non-Asian. We chose three treatment regimens used for NSCLC globally: cisplatin plus gemcitabine (CG), cisplatin plus vinorelbine (CV), and carboplatin plus paclitaxel (CP). We applied sensitivity analysis to examine unreported ethnic differences in hematological toxicities by changing the percentage of Asian patients from 0 to 18% in trials reported from the United States and Europe.

RESULTS

We identified 12 phase II trials and 38 phase III trials of NSCLC with a total of 11,271 patients. Among these, 14 trials had reported ethnic origins. Grade 3/4 toxicities were more frequently observed in the Asian studies. On the basis of sensitivity analysis, odds ratio of grade 3/4 neutropenia was significantly higher in Asian patients than non-Asian, when treated with CG (OR = 1.55-3.45, p < 0.001), CV (OR = 2.99-4.43, p < 0.001), and CP (OR = 4.79-6.22, p < 0.001). Grade 3/4 anemia was also significantly higher in Asians with CG (OR = 3.10-3.27, p < 0.001), CV (OR = 1.99-2.43, p < 0.001), and CP (OR = 1.34-1.52, p < 0.001-0.004). However, no significant difference was observed in thrombocytopenia with CG (OR = 0.66-2.04, p < 0.001-1.000), CV (OR = 0.42-0.57, p = 0.097-0.323), or CP (OR = 1.21-1.39, p = 0.114-0.152).

CONCLUSIONS

Severe hematological toxicity was frequently observed in Asian patients compared with non-Asian (mostly whites) in the treatment of chemotherapy for NSCLC.

Role of epigenetics in cancer health disparities

Cancer disparities in incidence and death rates exist among various racial and ethnic groups. These disparities are thought to be due to socioeconomic status, culture, diet, stress, the environment, and biology. Biological functions, such as epigenetic processes, are affected by all these causal factors and extend throughout the life course. Epigenetic processes, in particular DNA methylation, may play a role in the induction of phenotypes with increased cancer risk due to exposure to these multiple factors. DNA methylation is known to cause changes in gene expression of key regulatory genes in cancer. There are limited studies in which epigenetic changes have been explored to address cancer disparities in various racial and ethnic populations. These few studies have reported significant epigenetic differences in various racial and ethnic groups that could account for the differences seen in tumor initiation, progression, aggressiveness, and outcome of these cancers. Genes differentially methylated among these racially and ethnically diverse populations were involved in important cellular functions, such as tumor growth, tumor suppression, hormone receptors, and genes involved in tumor metastasis. Epigenetic research with the advancement in technology has helped identify biomarkers, therapeutic targets, and understand cancer causation in the general population. Unfortunately, these advances in technology have not been applied to explore the basis for cancer health disparities. More research in epigenetics is needed that will enhance our understanding of the determinants of cancer across various diverse populations and ultimately reduce cancer health disparities.

Pharmacogenomics of cisplatin-based chemotherapy in ovarian cancer patients of different ethnic origins

AIM

There is a substantial difference between Asians and Caucasians in their reaction to platinum drugs. To determine whether population-related genomics contribute to differences in patient outcomes, pharmacogenomic relevance of polymorphisms in some genes, the protein activities of which may affect aspects of cisplatin metabolism, were evaluated.

PATIENTS & METHODS

Nineteen polymorphisms in ten genes were tested for correlations with the efficacy and toxicity of a cisplatin-cyclophosphamide regimen in Yakut and Russian patients with ovarian cancer.

RESULTS

The CYP2E1 7632T>A polymorphism was associated with progression-free survival (p = 0.015) in Yakuts. In Russians, progression-free survival was correlated with the GSTP1 Ile105Val polymorphism (p = 0.004). Yakut patients with the GSTT1-null genotype had a higher risk for nephrotoxicity. By contrast, in the Russian group, nephrotoxicity was more frequent among patients with heterozygous ERCC1 genotypes. Severe emesis in Yakuts was independently associated with two polymorphisms in the CYP2E1 gene but in Russians, it was more common in patients with the GSTT1-null genotype. Differences in genotypic correlations with anemia were also observed.

CONCLUSION

Significant differences in genotype distribution between Russian and Yakut women were observed for ten of the 19 polymorphisms, but none of them seemed to be a clear casual candidate and further studies involving more markers are required.

An update on ethnic differences in drug metabolism and toxicity from anti-cancer drugs

INTRODUCTION

Based on recent emerging evidence of inter-ethnic differences in drug response and toxicity, ethnic diversity in pharmacokinetics, pharmacogenomics and clinical outcomes are being increasingly investigated. Ultimately, this will promote improved understanding of inter-individual differences in the pharmacokinetics and tolerance of cytotoxic drugs.

AREAS COVERED

This article reviews potential explanations for the observed ethnic differences in treatment outcomes and provides clinical data to support this concept. A literature search was implemented on PubMed and PharmGKB to investigate the areas of ethnic differences in pharmacogenomics, pharmacogenetics and clinical outcomes of cancer therapies.

EXPERT OPINION

There has been a relative paucity of clinical evidence linking genetic polymorphisms of genes encoding drug-metabolizing enzymes to the pharmacokinetics, pharmacodynamics and tolerance of anti-cancer drugs. Future research should focus on studies using large sample sizes, in the hope that they will provide results of high clinical significance. Due to the potential for ethnic differences to impact on both toxicities and benefits of systemic cancer therapies, the development of new therapeutic agents should include patients from diverse geographical ancestries in each phase of drug development.

Global experience with ixabepilone in breast cancer

Ixabepilone approval in a number of countries across the world as monotherapy and in combination with capecitabine has led to widespread uptake in the later-line breast cancer setting. However, individualized data for ixabepilone in different ethnic groups are limited. Overall, data from small numbers of ethnic subgroups including Hispanic, Japanese and Chinese patients have revealed no clinically significant variation in the disposition, efficacy or tolerability of ixabepilone from that established in pivotal trials. Global use of ixabepilone, while usually along the lines of standard practice, may vary because of local regulatory decisions, clinical practice guidelines and cost considerations. Further information on the global patterns of use of ixabepilone will assist in optimizing the use of this novel therapy.

A pharmacokinetic and safety study of single dose intravenous combretastatin A4 phosphate in Chinese patients with refractory solid tumours

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

• Three pharmacokinetic and safety studies for combretastatin A4 phosphate (CA4P), the first vascular disrupting agent, have been conducted in Western countries. • The maximum tolerated dose (MTD) was approximately 60-68 mg m(-2). • CA4P-related grade 3 or 4 adverse events were tumour pain, dyspnoea, hypoxia and syncope in patients who received doses ≥ 50 mg m(-2).

WHAT THIS STUDY ADDS

• This is the first pharmacokinetic and safety study conducted in East Asian patients. • There appeared to be a trend that Chinese patients metabolized CA4 more rapidly and had greater neurotoxicity than patients in Western countries. • We observed favourable clinical responses in patients with refractory nasopharyngeal carcinoma. • CA4P-induced acute renal failure was seen in one dehydrated Chinese patient.

AIMS

This trial was conducted to evaluate the safety and pharmacokinetics of combretastatin A4 phosphate (CA4P) given intravenously as a single dose to Chinese patients with refractory solid tumours. METHODS Twenty-five patients were treated with single doses of CA4P according to a dose escalation scheme: 5, 10, 20, 33, 50, 65 and 85 mg m(-2) infused intravenously over 30 min.

RESULTS

CA4P was generally well tolerated at ≤ 65 mg m(-2). Transient, moderate increases in the heart rate-corrected QT interval occurred at all doses. CA4P produced a transient dose-dependent increase in neural and gastrointestinal toxicities. Acute renal failure occurred in one dehydrated patient who had also taken paracetamol. There were seven episodes of dose-limiting toxicity at doses ≥65 mg m(-2), including two episodes of reversible ataxia at 85 mg m(-2).For CA4, at 50 mg m(-2),mean (SD) peak plasma concentration (C(max) was 0.99 (0.33) mM, area under the curve from time zero to time of last quantifiable concentration (AUC(0,t)) was 1.42 (0.30) mM h and terminal elimination half-life (t(1/2)was 1.81 (0.61) h. At 65 mg m-2,C(max) was 1.73 (0.62) mM,AUC(0,t) was 3.19 (1.47) mM h and t (1/2) was 1.90 (0.61) h [corrected]One patient with nasopharyngeal carcinoma had an obvious clinical response with central necrosis in the metastatic lung mass. CONCLUSION Doses ≤ 65 mg m(-2) given as 30 min infusions define the maximum tolerated dose in East Asian patients, and doses in the range of 50-65 mg m(-2) have been selected for further studies.

Establishment and characterization of primary lung cancer cell lines from Chinese population

AIM

To establish and characterize primary lung cancer cell lines from Chinese population.

METHODS

Lung cancer specimens or pleural effusions were collected from Chinese lung cancer patients and cultured in vitro with ACL4 medium (for non-small cell lung carcinomas (NSCLC)) or HITES medium (for small cell lung carcinomas (SCLC)) supplemented with 5% FBS. All cell lines were maintained in culture for more than 25 passages. Most of these cell lines were further analyzed for oncogenic mutations, karyotype, cell growth kinetics, and tumorigenicity in nude mice.

RESULTS

Eight primary cell lines from Chinese lung cancer patients were established and characterized, including seven NSCLC cell lines and one SCLC cell line. Five NSCLC cell lines were found to harbor epidermal growth factor receptor (EGFR) kinase domain mutations.

CONCLUSION

These well-characterized primary lung cancer cell lines from Chinese population provide a unique platform for future studies of the ethnic differences in lung cancer biology and drug response.

Challenges in recruiting Mexican women for cancer genetics research

Hispanic women often have low participation rates in cancer genetics research. Additionally, Hispanic sub-ethnicities may have varying accrual rates based on unique cultural factors. Hispanic women were recruited through flyers placed in the Tampa Bay Community to participate in an interview about knowledge of hereditary breast and ovarian cancer. The study goal was to recruit 20 women from each Hispanic sub-ethnicity: Puerto Rican, Mexican, and Cuban. This article reports on the difficulty in recruiting Mexican women. One hundred forty-three women called the study hotline to inquire about participation. Seventy-six callers were ineligible for the study. Thirty-four percent (n = 26) of ineligibles were Mexican women; within this group, 62% (n = 16) were unable to participate because they did not know the cancer site of their first degree relative. Inclusion criteria requiring knowledge of family history of cancer for behavioral research may be too stringent. The socio-cultural norms of Mexican families may not include discussions of cancer specifics. This study demonstrates Mexican women may have limited knowledge about their family history of cancer. Considerations of these knowledge limitations should be built into cancer genetics-related research. Referral criteria to assess the risk of hereditary breast and ovarian cancer by cancer genetics professionals are predicated on the patient providing details about cancer within multiple generations of family members, thus, posing a barrier for Mexican women who may have limited knowledge of their family history of cancer.

Age and sex dependent changes in liver gene expression during the life cycle of the rat

Background

Age- and sex-related susceptibility to adverse drug reactions and disease is a key concern in understanding drug safety and disease progression. We hypothesize that the underlying suite of hepatic genes expressed at various life cycle stages will impact susceptibility to adverse drug reactions. Understanding the basal liver gene expression patterns is a necessary first step in addressing this hypothesis and will inform our assessments of adverse drug reactions as the liver plays a central role in drug metabolism and biotransformation. Untreated male and female F344 rats were sacrificed at 2, 5, 6, 8, 15, 21, 52, 78, and 104 weeks of age. Liver tissues were collected for histology and gene expression analysis. Whole-genome rat microarrays were used to query global expression profiles.

Results

An initial list of differentially expressed genes was selected using criteria based upon p-value (p < 0.05) and fold-change (+/- 1.5). Three dimensional principal component analyses revealed differences between males and females beginning at 2 weeks with more divergent profiles beginning at 5 weeks. The greatest sex-differences were observed between 8 and 52 weeks before converging again at 104 weeks. K-means clustering identified groups of genes that displayed age-related patterns of expression. Various adult aging-related clusters represented gene pathways related to xenobiotic metabolism, DNA damage repair, and oxidative stress.

Conclusions

These results suggest an underlying role for genes in specific clusters in potentiating age- and sex-related differences in susceptibility to adverse health effects. Furthermore, such a comprehensive picture of life cycle changes in gene expression deepens our understanding and informs the utility of liver gene expression biomarkers.

Effect of ethnicity on the hypnotic and cardiovascular characteristics of propofol induction

We compared the propofol dose causing loss of verbal response and suppression of bispectral index to 50, between 50 white and 50 black patients, aged 18-65 years. Propofol was administered at 40 mg.kg⁻¹.h⁻¹ and reduced to 8 mg.kg⁻¹.h⁻¹ when bispectral index fell to 50. We recorded heart rate and mean arterial pressure for 15 min in total and calculated, for this period, maximal percentage change from baseline for each. A statistician, blinded to patient ethnicity, found mean (SD) propofol dose for loss of verbal response in white and black patients to be 1.41 (0.37) mg.kg⁻¹ and 1.16 (0.25) mg.kg⁻¹, respectively (p < 0.001). Corresponding figures for maximal percentage change in heart rate were 14.1 (12.6) % and 7.5 (14.0) % (p = 0.015). Other differences were non-significant. The dose of propofol required for loss of verbal response, but not for suppression of bispectral index to 50, is lower in black than in white patients.

Does Race Affect Outcomes in Triple Negative Breast Cancer?

Background

There is discordance among studies assessing the impact of race on outcome of patients with Triple Negative Breast Cancer (TNBC). We assessed survival outcomes for African American (AA) versus Caucasian (CA) women with TNBC treated at an urban cancer center in Memphis, TN with a predominant AA patient population.

Methods

Patients with Stage I-III TNBC were identified from our breast database. Event free survival (EFS) and Breast cancer specific survival (BCSS) were the primary outcome measures. Cox proportional hazards models were fitted for EFS and BCSS.

Results

Of the 124 patients, 71% were AA. No significant association between race and stage ( P = 0.21) or menopausal status ( P = 0.15) was observed. Median age at diagnosis was significantly lower for AA versus CA women (49.5 vs. 55 years, P = 0.024). 92% of the patients received standard neo/adjuvant chemotherapy, with no significant difference in duration and type of chemotherapy between the races. With a median follow up of 23 months, 28% of AA vs. 19% of CA women had an event ( P = 0.37). 3 year EFS and BCSS trended favorably towards CA race (77% vs. 64%, log rank P = 0.20 and 92% vs. 76%, P = 0.13 respectively) with a similar trend noted on multiple variable modeling (EFS: HR 0.62, P = 0.29; BCSS: HR 0.36, P = 0.18). AA women ≥50 years at diagnosis had a significantly worse BCSS than the CA women in that age group ( P = 0.012).

Conclusion

Older AA women with TNBC have a significantly worse breast cancer specific survival than their CA counterparts. Overall, there is a trend towards lower survival for AA women compared to Caucasians despite uniformity of tumor phenotype and treatment. The high early event rate, irrespective of race, underscores the need for effective therapies for women with TNBC.

Performing phase I clinical trials of anticancer agents: perspectives from within the European union and Japan

Drug discovery and early clinical development is an international endeavor, conducted in partnership between commercial entities such as biotechnology and pharmaceutical companies and academic investigators. Although once considered quite disparate, early clinical trials requirements and conduct are largely harmonized between the European Union, Japan, and the United States, increasing the opportunities for productive commercial-academic collaborations.