Anshul Saxena

Bayesian Method for Modeling Male Breast Cancer Survival Data

BACKGROUND With recent progress in health science administration, a huge amount of data has been collected from thousands of subjects. Statistical and computational techniques are very necessary to understand such data and to make valid scientific conclusions. The purpose of this paper was to develop a statistical probability model and to predict future survival times for male breast cancer patients who were diagnosed in the USA during 1973-2009. MATERIALS AND METHODS A random sample of 500 male patients was selected from the Surveillance Epidemiology and End Results (SEER) database. The survival times for the male patients were used to derive the statistical probability model. To measure the goodness of fit tests, the model building criterions: Akaike Information Criteria (AIC), Bayesian Information Criteria (BIC), and Deviance Information Criteria (DIC) were employed. A novel Bayesian method was used to derive the posterior density function for the parameters and the predictive inference for future survival times from the exponentiated Weibull model, assuming that the observed breast cancer survival data follow such type of model. The Markov chain Monte Carlo method was used to determine the inference for the parameters. RESULTS The summary results of certain demographic and socio-economic variables are reported. It was found that the exponentiated Weibull model fits the male survival data. Statistical inferences of the posterior parameters are presented. Mean predictive survival times, 95% predictive intervals, predictive skewness and kurtosis were obtained. CONCLUSIONS The findings will hopefully be useful in treatment planning, healthcare resource allocation, and may motivate future research on breast cancer related survival issues.

HIV Vaccine: Recent Advances, Current Roadblocks, and Future Directions

HIV/AIDS is a leading cause of mortality and morbidity worldwide. In spite of successful interventions and treatment protocols, an HIV vaccine would be the ultimate prevention and control strategy. Ever since identification of HIV/AIDS, there have been meticulous efforts for vaccine development. The specific aim of this paper is to review recent vaccine efficacy trials and associated advancements and discuss the current challenges and future directions. Recombinant DNA technologies greatly facilitated development of many viral products which were later incorporated into vectors for effective vaccines. Over the years, a number of scientific approaches have gained popularity and include the induction of neutralizing antibodies in late 1980s, induction of CD8 T cell in early 1990s, and combination approaches currently. Scientists have hypothesized that stimulation of right sequences of somatic hypermutations could induce broadly reactive neutralizing antibodies (bnAbs) capable of effective neutralization and viral elimination. Studies have shown that a number of host and viral factors affect these processes. Similarly, eliciting specific CD8 T cells immune responses through DNA vaccines hold future promises. In summary, future studies should focus on the continuous fight between host immune responses and ever-evasive viral factors for effective vaccines.

Selenium and vitamin E for prostate cancer--justifications for the SELECT study.

There are several studies that relate oxidative damage as possible mechanism for many cancers. Many studies have also shown that anti-oxidants like selenium and vitamin E decrease the risk for prostate cancer. The main objective of the Selenium and Vitamin E Cancer Prevention Trial (SELECT) study was to look for the benefits of selenium and vitamin E supplementation on prostate cancer. The study had a large sample size, stringent experimental conditions, very long duration, standardized laboratories for biochemical analyses and other factors that contribute to high external validity. The SELECT study failed to show any significant risk reduction for prostate cancers ascribable to selenium and vitamin E supplementations. Because of these conflicting results, many researchers argue about the methods used, supplementations administered (selenium and vitamin E) and indicators used for assessing levels of supplementations. We reviewed many epidemiological studies, clinical trials, and pre-clinical studies. With corroborative evidences we justify that SELECT study has a sound methodology and rationale. In lieu of the contrary results of the select study, researchers should focus on the probable mechanisms for these contrary findings and continue their search for newer and effective agents for prevention of prostate cancer.

Health promotion and disease prevention strategies for today's physicians.

Abstract:The majority of preventable diseases in both developed and developing countries could be strategically controlled by effectively implementing existing health promotion and disease prevention (HPDP) interventions. An important juncture for the implementation of risk-reduction strategies is the point of interaction between health care providers and patients during their scheduled visits. This article targets strategies for physicians to effectively implement HPDP interventions in a clinical setting. The factors that improve delivery of HPDP interventions are discussed briefly. We subsequently introduce and discuss the conceptual framework for enhanced patient education, which is based on the information-motivation-behavioral skills model and the health belief model. The article also describes an adapted patient-practitioner collaborative model for HPDP. This adapted model may serve as a blueprint for physicians to effectively execute HPDP interventions during clinical encounters. The recommended models and our conceptual frameworks could have limitations which need to be field tested.

A review of 5-HT transporter linked promoter region (5-HTTLPR) polymorphism and associations with alcohol use problems and sexual risk behaviors.

Alcohol use and sexual risk behaviors are multidimensional phenomena involving many genetic and environmental factors. 5-HT transporter linked promoter region (5-HTTLPR) polymorphism constitutes an important factor affecting alcohol use problems and risky sexual behaviors. This paper narratively reviews studies on 5-HTTLPR polymorphism and its associations with alcohol use problems and sexual risk behaviors. We searched the electronic databases, PubMed, Ovid, and Google Scholar for articles using MeSH terms. Relevant articles were reviewed and eligible articles were selected for the study. Many studies have reported a significant but moderate association between 5-HTTLPR polymorphism and alcohol use problems. These studies have implicated the presence of at least one S allele to be associated with significant increases in alcohol use problems. Similarly, some studies associate the S allele with increased sexual risk behaviors. Effective alcohol cessation initiatives and STI/HIV prevention programs should be modified to account for 5-HTTLPR polymorphism before planning interventions; genetic effects could moderate the intervention effect.

Risk of Second Cancers in Merkel Cell Carcinoma: A Meta-Analysis of Population Based Cohort Studies

The risk of second cancers in Merkel cell carcinoma (MCC) remains uncertain since risk estimates vary worldwide. The global MCC population is growing and there is a demand for better knowledge of prognosis of this disease. The Cochrane Database of Systematic Reviews, MEDLINE, and EMBASE search engines were searched for the relevant literature between January 1999 and September 2014 by use of explicit search criteria. The main outcome was second malignancies associated with MCC patients measured by standardized incidence ratios (SIRs) or other estimates of risks. Five papers fulfilled the inclusion criteria and reported SIRs of second cancer in MCC which varied from 1.07 to 2.80. Performing meta-analysis using random effects model revealed that there was an increased risk for second malignancies due to MCC (SIR, 1.52; 95% CI, 1.10–2.11). There was a significant increase in risk for malignant melanoma (SIR, 3.09; 95% CI, 2.02–4.73) as compared to all common second malignancies among the studies. Updated knowledge about risk of second malignancies in MCC will help in better assessment of the disease prognosis and will help in optimizing the medical and surgical treatment, radiotherapy, follow-up, and surveillance procedures.

Health disparities between Black Hispanic and Black non-Hispanic cervical cancer cases in the USA.

BACKGROUND Globally, cervical cancer is a major public health concern. Cervical cancer is the second most common cancer among women, resulting in approximately 500,000 cases per year. The purpose of this study is to compare disease characteristics between Black Hispanic (BH) and Black non-Hispanic (BNH) women in the US. MATERIALS AND METHODS We used stratified random sampling to select cervical cancer patient records from the SEER database (1973-2009). We used Chi-square and independent samples t-test to examine differences in proportions and means. RESULTS The sample included 2,000 cervical cancer cases of Black non-Hispanic and 91 Black Hispanic women. There were statistically significant differences between black Hispanic and black non- Hispanics in mean age at diagnosis (p<0.001), mean survival time (p<0.001), marital status (p<0.001), primary site of cancer (p<0.001); lymph node involvement (p<0.001); grading and differentiation (p<0.0001); and tumor behavior (p<0.001). Black women were more likely to develop cervical cancer and to have the highest mortality rates from the disease. CONCLUSIONS Findings from this study show clear racial and ethnic disparities in cervical cancer incidence and prognosis that should be addressed.

The Impact of 2017 ACC/AHA Guidelines on the Prevalence of Hypertension and Eligibility for Anti-Hypertensive Therapy in the United States and China

BACKGROUND The 2017 American College of Cardiology (ACC)/American Heart Association (AHA) guideline recommendations for hypertension include major changes to the diagnosis of hypertension as well as suggested treatment targets for blood pressure management. To better guide future health policy interventions in the management of hypertension, we examined the effect of these guidelines on the prevalence as well as the eligibility for initiation and intensification of therapy in nationally-representative populations from the US and China. METHODS In the National Health and Nutrition Examination Survey (NHANES) for the most recent 2 cycles (2013-2014 and 2015-2016), and the China Health and Retirement Longitudinal Study (CHARLS) (2011-2012), we identified all adults 45 to 75 years of age who would have a diagnosis of hypertension, and would be candidates for initiation and intensification of anti-hypertensive therapy based on the 2017 ACC/AHA guidelines, compared with current guidelines. RESULTS The adoption of the 2017 ACC/AHA guidelines for hypertension in the US would label 70.1 million individuals in the 45-75-year age group with hypertension, representing 63% of the population in this age-group. The adoption of these guidelines in China would lead to labeling of 267 million or 55% individuals in the same age-group with hypertension. This would represent a relative increase in the prevalence of hypertension by 26.8% in the US and 45.1% in China with the adoption of the new guidelines. Further, based on observed treatment patterns and current guidelines, 8.1 million Americans with hypertension are currently untreated. However, this number is expected to increase to 15.6 million after the implementation of the 2017 ACC/AHA guidelines. In China, based on current treatment patterns, 74.5 million patients with hypertension are untreated, and is estimated to increase to 129.8 million if the 2017 ACC/AHA guidelines are adopted by China. In addition, the new ACC/AHA guidelines will label 8.7 million adults in the US, and 51 million in China with hypertension who would not require treatment with an anti-hypertensive agent, compared with 1.5 million and 23.4 million in the current guidelines. Finally, even among those treated with anti-hypertensive therapy, the proportion of undertreated individuals, i.e. those above target blood pressures despite receiving anti-hypertensive therapy and candidates for intensification of therapy, is estimated to increase by 13.9 million (from 24.0% to 54.4% of the treated patients) in the US, and 30 million (41.4% to 76.2% of patients on treatment) in China, if the 2017 ACC/AHA treatment targets are adopted into clinical practice in the respective countries. Conclusions Adopting the new 2017 ACC/AHA hypertension guidelines would be associated with a substantial increase in the prevalence of hypertension in both US and China accompanied with a marked increase in the recommendation to initiate and intensify treatment in several million patients. There would be a 26.8% and 45.1% increase in those labeled with hypertension in the US and China, respectively. Further, 7.5 million and 55.3 million will be newly recommended for therapy, and 13.9 million and 30 million newly recommended for intensification of existing therapy in the US and China, respectively.

Effect of Thyroxin Treatment on Carotid Intima–Media Thickness (CIMT) Reduction in Patients with Subclinical Hypothyroidism (SCH): a Meta-Analysis of Clinical Trials

Aim: Research shows that subclinical hypothyroidism (SCH) is related to an increased carotid intima –media thickness (CIMT), a surrogate marker of subclinical cardiovascular disease (CVD). It is controversial whether or not SCH should be treated to reduce CVD morbidity and mortality. This meta-analysis aimed to determine whether SCH is associated with an increase in CIMT as compared to Euthyroidism (EU) and whether thyroxin (T4) treatment in SCH can reverse the change in CIMT. Methods: Two independent reviewers conducted an extensive database research up to December 2016. A total of 12 clinical trials discussed the effect of Thyroxin on CIMT values at pre- and post-treatment in subjects with SCH. Results: CIMT was significantly higher among SCH (n = 280) as compared to EU controls (n = 263) at baseline; the pooled weighted mean difference (WMD) of CIMT was 0.44 mm [95% confidence interval (CI) 0.14, 0.74], p = 0.004; I2 = 65%. After treatment with thyroxin in subjects with SCH (n = 314), there was a statistically significant decrease in CIMT from pre- to post-treatment; the pooled WMD of CIMT decrease was [WMD −0.32; 95% CI (−0.47, −0.16), p = < 0.0001; I2 = 2%], and it was no longer different from EU controls [WMD 0.13 mm; 95% CI (−0.04, 0.30); p = 0.14; I2 = 27%]. The total cholesterol (TC), triglycerides (TG), and low-density lipoprotein (LDL) were higher in SCH as compared to EU controls and decreased significantly after treatment with thyroxin. Conclusion: This meta-analysis shows that thyroxin therapy in subjects with SCH significantly decreases CIMT and improves lipid profile, modifiable CVD risk factors. Thyroid hormone replacement in subjects with SCH may play a role in slowing down or preventing the progression of atherosclerosis.

A childhood acute lymphoblastic leukemia genome-wide association study identifies novel sex-specific risk variants

AbstractChildhood acute lymphoblastic leukemia (ALL) occurs more frequently in males. Reasons behind sex differences in childhood ALL risk are unknown. In the present genome-wide association study (GWAS), we explored the genetic basis of sex differences by comparing genotype frequencies between male and female cases in a case-only study to assess effect-modification by sex.The case-only design included 236 incident cases of childhood ALL consecutively recruited at the Texas Childrens Cancer Center in Houston, Texas from 2007 to 2012. All cases were non-Hispanic whites, aged 1 to 10 years, and diagnosed with confirmed B-cell precursor ALL. Genotyping was performed using the Illumina HumanCoreExome BeadChip on the Illumina Infinium platform. Besides the top 100 statistically most significant results, results were also analyzed by the top 100 highest effect size with a nominal statistical significance (P <0.05).The statistically most significant sex-specific association (P = 4 × 10−6) was with the single nucleotide polymorphism (SNP) rs4813720 (RASSF2), an expression quantitative trait locus (eQTL) for RASSF2 in peripheral blood. rs4813720 is also a strong methylation QTL (meQTL) for a CpG site (cg22485289) within RASSF2 in pregnancy, at birth, childhood, and adolescence. cg22485289 is one of the hypomethylated CpG sites in ALL compared with pre-B cells. Two missense SNPs, rs12722042 and 12722039, in the HLA-DQA1 gene yielded the highest effect sizes (odds ratio [OR] ∼ 14; P <0.01) for sex-specific results. The HLA-DQA1 SNPs belong to DQA1*01 and confirmed the previously reported male-specific association with DQA1*01. This finding supports the proposed infection-related etiology in childhood ALL risk for males. Further analyses revealed that most SNPs (either direct effect or through linkage disequilibrium) were within active enhancers or active promoter regions and had regulatory effects on gene expression levels.Cumulative data suggested that RASSF2 rs4813720, which correlates with increased RASSF2 expression, may counteract the suppressor effect of estrogen-regulated miR-17-92 on RASSF2 resulting in protection in males. Given the amount of sex hormone-related mechanisms suggested by our findings, future studies should examine prenatal or early postnatal programming by sex hormones when hormone levels show a large variation.