Chemopreventive role of vitamin D in colorectal carcinoma

A Review of Colorectal Cancer in Terms of Epidemiology, Risk Factors, Development, Symptoms and Diagnosis

This review article contains a concise consideration of genetic and environmental risk factors for colorectal cancer. Known risk factors associated with colorectal cancer include familial and hereditary factors and lifestyle-related and ecological factors. Lifestyle factors are significant because of the potential for improving our understanding of the disease. Physical inactivity, obesity, smoking and alcohol consumption can also be addressed through therapeutic interventions. We also made efforts to systematize available literature and data on epidemiology, diagnosis, type and nature of symptoms and disease stages. Further study of colorectal cancer and progress made globally is crucial to inform future strategies in controlling the disease's burden through population-based preventative initiatives.

The Role of Nicotinamide in Cancer Chemoprevention and Therapy

Nicotinamide (NAM) is a water-soluble form of Vitamin B3 (niacin) and a precursor of nicotinamide-adenine dinucleotide (NAD⁺) which regulates cellular energy metabolism. Except for its role in the production of adenosine triphosphate (ATP), NAD⁺ acts as a substrate for several enzymes including sirtuin 1 (SIRT1) and poly ADP-ribose polymerase 1 (PARP1). Notably, NAM is an inhibitor of both SIRT1 and PARP1. Accumulating evidence suggests that NAM plays a role in cancer prevention and therapy. Phase III clinical trials have confirmed its clinical efficacy for non-melanoma skin cancer chemoprevention or as an adjunct to radiotherapy against head and neck, laryngeal, and urinary bladder cancers. Evidence for other cancers has mostly been collected through preclinical research and, in its majority, is not yet evidence-based. NAM has potential as a safe, well-tolerated, and cost-effective agent to be used in cancer chemoprevention and therapy. However, more preclinical studies and clinical trials are needed to fully unravel its value.

Progress in Drug and Formulation Development for the Chemoprevention of Oral Squamous Cell Carcinoma: A Review

BACKGROUND

Cancer is a life-threatening global problem with high incidence rates. Prioritizing the prevention of cancer, chemopreventive agents have drawn much attention from the researchers.

OBJECTIVE

This review focuses on the discussion of the progress in the development of chemopreventive agents and formulations related to the prevention of oral cancer.

METHODS

In this perspective, an extensive literature survey was carried out to understand the mechanism, control and chemoprevention of oral cancer. Different patented agents and formulations have also exhibited cancer preventive efficacy in experimental studies. This review summarizes the etiology of oral cancer and developments in prevention strategies.

RESULTS

The growth of oral cancer is a multistep activity necessitating the accumulation of genetic as well as epigenetic alterations in key regulatory genes. Many risk factors are associated with oral cancer. Genomic technique for sequencing all tumor specimens has been made available to help detect mutations. The recent development of molecular pathway and genetic tools has made the process of diagnosis easier, better forecast and efficient therapeutic management. Different chemical agents have been studied for their efficacy to prevent oral cancer and some of them have shown promising results.

CONCLUSION

Use of chemopreventive agents, either synthetic or natural origin, to prevent carcinogenesis is a worthy concept in the management of cancers. Preventive measures are helpful in controlling the occurrence or severity of the disease. The demonstrated results of preventive agents have opened an arena for the development of promising chemopreventive agents in the management of oral squamous cell carcinoma.

Pattern, Stage, and Time of Recurrent Colorectal Cancer After Curative Surgery

Surgery remains the mainstay of curative treatment for colorectal cancer (CRC). Despite curative surgery, some patients experience cancer recurrence. However, the pattern, stage, and time of recurrent disease (RD) remain unknown. We aimed to determine the pattern and stage of RD after curative open and laparoscopic surgery for CRC. Databases were searched using selected keywords for clinical studies that analyzed the pattern, stage, and time of RD from CRC. A systematic protocol was used for data extraction, data synthesis, and interpretation of results. Of 455 publications retrieved from databases, 9 clinical studies were selected for this systematic review. There is substantial evidence that pulmonary recurrence is most commonly associated with rectal tumors, and multisite RD appears more frequently with right-sided CRC. RD from colon cancers predominantly appears early in liver, while recurrences from rectal cancer appear late in lungs. Approximately 30% to 50% of RD after curative resection of CRC occurs within the first 2 years; however, median time to recurrence is gradually increasing, particularly for patients with rectal cancers. Advanced primary CRC is significantly correlated with more locoregional and distant RD, with worse disease-free survival. There is a decrease in the 5-year incidence of RD that is associated with prolongation of time of RD for both locoregional and metastatic disease. The duration and design of postoperative follow-up protocols for recurrences from CRC should be tailored to site and stage of primary tumor, as rectal cancers demand longer surveillance times than colon cancer.

Prognostic significance of circulating microRNA-21 expression in esophageal, pancreatic and colorectal cancers; a systematic review and meta-analysis

BACKGROUND

Literature has shown that aberrantly expressed microRNAs may have implications in certain cancers. A wealth of studies signal potential prognostic role of microRNA-21 in GIT cancers. This meta-analysis quantitatively determines prognostic significance of circulating microRNA-21 in esophageal squamous cell carcinoma (ESCC), pancreatic ductal adenocarcinoma (PDAC) and colorectal carcinoma (CRC).

METHODS

Databases of Medline, Wiley online library, Cochrane library, Taylor and Francis Online, CINAHL, Springer, Proquest, ISI Web of knowledge, ScienceDirect, and Emerald were searched using MeSH terms serum/tissue microRNA-21, prognosis, esophagus squamous cell carcinoma, pancreatic ductal adenocarcinoma, colorectal cancer. A systematic algorithm was used that selected 15 relevant studies. Meta-analysis was conducted using forest plot and a summary effect model was employed.

RESULTS

This meta-analysis reports significant prognostic value of miR-21 in predicting worse overall survival (OS) in ESCC, PDAC, and CRC with pooled hazard ratio (HR) of 3.49 (95% CI 2.58-4.71, p-value < 0.01). Subgroup analysis for ESCC showed a pooled HR of 3.46 (95% CI 1.88-635, p value of <0.01), worse overall survival (OS) with the pooled HR of 3.14 (95% CI 2.22-4.43, p value < 0.01) for CRC and a pooled HR of 3.77 (95% CI 1.63-8.73, p value < 0.01) for PDAC.

CONCLUSION

This research infers that microRNA-21 expression is a powerful prognostic tool. Expression of micro-RNA-21 is associated with poor OS and poorer disease-free survival in ESCC, PDAC and CRC.

Correlation of clinical, radiological and serum analysis of hypovitaminosis D with polycystic ovary syndrome: A systematic review and meta-analysis

Objectives

Vitamin D deficiency leads to a myriad of healthcare problems from cardiovascular, metabolic, endocrine, and neurological disorders to cancer. However, the role of vitamin D deficiency in the etiopathogenesis of polycystic ovary syndrome (PCOS) is unclear. This study aimed to measure objectively the impact of vitamin D deficiency on PCOS through a quantitative assessment of the existing literature.

Methods

We conducted a systematic search of published literature on the following online databases using EndnoteX7: MEDLINE, EBSCO, ScienceDirect, and CINAHL. Searches were limited to full-text English-language journal articles published between 2006 and 2016. Eligible clinical studies employed control group data to investigate the association between vitamin D deficiency and PCOS.

Results

We identified 10 studies eligible for this meta-analysis. The summary intervention effect calculated for this meta-analysis yields a value of −0.45 with a confidence interval of −1.68 to 0.79, supporting the hypothesis that lower concentrations of serum vitamin D play a role in the hormonal and metabolic dysregulation seen in PCOS.

Conclusions

Lower concentrations of serum vitamin D are associated with a greater risk of developing PCOS. However, the therapeutic effect of vitamin D in the setting of PCOS remains unclear and must be determined by future interventional studies.

Alpha-glucosidase inhibitor use is associated with decreased colorectal neoplasia risk in patients with type 2 diabetes mellitus receiving colonoscopy: a retrospective study

Purpose

The purpose of this study was to clarify the factors that influence the incidence of colorectal neoplasia in patients with type 2 diabetes mellitus (DM).

Study Design and Setting

Among a total of 1176 patients who underwent total colonoscopy at our hospital, we retrospectively analyzed 168 patients with type 2 DM. Univariate and multivariate logistic regression analyses were then performed to identify the risk factors associated with colorectal neoplasia.

Results

A multivariate analysis of these patients demonstrated that male gender (odds ratio [OR] = 4.04, 95% confidence interval [CI] = 1.67-10.37, p = 0.002), taking statins (OR = 4.59, 95% CI = 1.69-13.43, p = 0.003), taking alpha glucosidase inhibitor (α-GI) (OR = 0.35, 95% CI = 0.13-0.87, p = 0.023) and taking low-dose aspirin (LDA) (OR = 0.32, 95% CI = 0.10-0.95, p = 0.040) were independent factors associated with an increased (male gender and statins) or decreased (α-GI and LDA) risk of colorectal neoplasia.

Conclusions

While male gender and taking statins are risk factors, taking α-GI as well as LDA may reduce the risk of colorectal neoplasia in patients with type2 DM.

PLGA nanoparticles as a platform for vitamin D-based cancer therapy

Poly(lactic-co-glycolic acid) (PLGA) nanoparticles were studied as drug delivery vehicles for calcitriol, the active form of vitamin D3. In vitro effects of calcitriol encapsulated in PLGA nanoparticles were evaluated with respect to free calcitriol on human pancreatic cell lines, S2-013 and hTERT-HPNE, and the lung cancer cell line A549. Encapsulated calcitriol retained its biological activity, reducing the cell growth. Cytotoxicity assays demonstrated that encapsulation of calcitriol enhanced its inhibitory effect on cell growth at a concentration of 2.4 μM for the S2-013 cells (91%) and for A549 cells (70%) comparared to the free calcitriol results. At this concentration the inhibitory effect on nontumor cells (hTERT-HPNE) decreased to 65%. This study highlights the ability of PLGA nanoparticles to deliver vitamin D3 into cancer cells, with major effects regarding cancer cell cycle arrest and major changes in the cell morphological features.

Association of type 2 diabetes mellitus and the risk of colorectal cancer: A meta-analysis and systematic review

AIM: To provide a quantitative assessment of the association between type 2 diabetes mellitus (T2DM) and the risk of colorectal cancer (CRC).

METHODS: Systematic review was conducted thorough MEDLINE, EMBASE, Cochrane Library, and ISI Web of knowledge databases till 31^st January 2014. This meta-analysis included the cohort studies that illustrated relative risk (RR) or odds ratio estimates with 95%CI for the predictive risk of CRC by T2DM. Summary relative risks with 95%CI were analyzed by using an effects summary ratio model. Heterogeneity among studies was assessed by the Cochran’s Q and I² statistics.

RESULTS: The meta analysis of 8 finally selected studies showed a positive correlation of T2DM with the risk of CRC as depicted by effects summary RR of 1.21 (95%CI: 1.02-1.42). Diabetic women showed greater risk of developing CRC as their effect summary RR of 1.22 (95%CI: 1.01-49) with significant overall Z test at 5% level of significance was higher than the effect summary RR of 1.17 (95%CI: 1.00-1.37) of men showing insignificant Z test. The effect summary RR of 1.19 with 95%CI of 1.07-1.33 indicate a positive relationship between DM and increased risk of CRC with significant heterogeneity (I² = 92% and P-value < 0.05).

CONCLUSION: Results from this systematic review and meta-analysis report that diabetic people have an increased risk of CRC as compared to non-diabetics.