Polymorphisms of Genes Related to Function and Metabolism of Vitamin D in Esophageal Adenocarcinoma

Is vitamin D receptor (VDR) polymorphism associated with head and neck cancer risk? A systematic review and meta-analysis

BACKGROUND

Head and neck cancer encompasses neoplasms affecting the oral cavity, pharynx, larynx, and thyroid. Identifying factors that modulate the carcinogenesis process can aid in identifying subgroups at higher risk of developing the disease, enabling implementation of prevention programs. Vitamin D receptor polymorphisms can affect the carcinogenesis of various tumors by altering vitamin D metabolism and cellular response.

METHODS

To elucidate the role of vitamin D receptor polymorphisms in head and neck cancer, a systematic review was performed, searching the Embase, PubMed, Scopus, and Lilacs databases. A total of 19 articles met the inclusion criteria. The frequency of vitamin D receptors polymorphism alleles (FokI, ApaI, BsmI, TaqI, Cdx2, rs2107301, rs2238135) was recorded and pooled to calculate the odds ratio in a meta-analysis using the Review Manager software.

RESULTS

Subgroup analysis demonstrated significant associations in the anatomical site of cancer (oral cancer in ApaI and BsmI, and unspecified subsites of head and neck cancer in TaqI), genotyping method (FokI and BsmI), and continent of the study (ApaI, FokI, and BsmI).

CONCLUSION

Our findings were heterogeneous, as with other evidence available in the literature. Therefore, more clinical studies with larger sample sizes are needed to obtain more accurate results on the relationship between vitamin D receptor polymorphism and head and neck cancer.

Biomarkers for Early Detection, Prognosis, and Therapeutics of Esophageal Cancers

Esophageal cancer (EC) is the deadliest cancer worldwide, with a 92% annual mortality rate per incidence. Esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC) are the two major types of ECs, with EAC having one of the worst prognoses in oncology. Limited screening techniques and a lack of molecular analysis of diseased tissues have led to late-stage presentation and very low survival durations. The five-year survival rate of EC is less than 20%. Thus, early diagnosis of EC may prolong survival and improve clinical outcomes. Cellular and molecular biomarkers are used for diagnosis. At present, esophageal biopsy during upper endoscopy and histopathological analysis is the standard screening modality for both ESCC and EAC. However, this is an invasive method that fails to yield a molecular profile of the diseased compartment. To decrease the invasiveness of the procedures for diagnosis, researchers are proposing non-invasive biomarkers for early diagnosis and point-of-care screening options. Liquid biopsy involves the collection of body fluids (blood, urine, and saliva) non-invasively or with minimal invasiveness. In this review, we have critically discussed various biomarkers and specimen retrieval techniques for ESCC and EAC.

Demystifying the Functional Role of Nuclear Receptors in Esophageal Cancer

Esophageal cancer (EC), an aggressive and poorly understood disease, is one of the top causes of cancer-related fatalities. GLOBOCAN 2020 reports that there are 544,076 deaths and 604,100 new cases expected worldwide. Even though there are various advancements in treatment procedures, this cancer has been reported as one of the most difficult cancers to cure, and to increase patient survival; treatment targets still need to be established. Nuclear receptors (NRs) are a type of transcription factor, which has a key role in several biological processes such as reproduction, development, cellular differentiation, stress response, immunity, metabolism, lipids, and drugs, and are essential regulators of several diseases, including cancer. Numerous studies have demonstrated the importance of NRs in tumor immunology and proved the well-known roles of multiple NRs in modulating proliferation, differentiation, and apoptosis. There are surplus of studies conducted on NRs and their implications in EC, but only a few studies have demonstrated the diagnostic and prognostic potential of NRs. Therefore, there is still a paucity of the role of NRs and different ways to target them in EC cells to stop them from spreading malignancy. This review emphasizes the significance of NRs in EC by discussing their diverse agonists as well as antagonists and their response to tumor progression. Additionally, we emphasize NRs’ potential to serve as a novel therapeutic target and their capacity to treat and prevent EC.

Predicting Response to Neoadjuvant Therapy in Oesophageal Adenocarcinoma

(1) Background: Oesophageal cancers are often late-presenting and have a poor 5-year survival rate. The standard treatment of oesophageal adenocarcinomas involves neoadjuvant chemotherapy with or without radiotherapy followed by surgery. However, less than one third of patients respond to neoadjuvant therapy, thereby unnecessarily exposing patients to toxicity and deconditioning. Hence, there is an urgent need for biomarkers to predict response to neoadjuvant therapy. This review explores the current biomarker landscape. (2) Methods: MEDLINE, EMBASE and ClinicalTrial databases were searched with key words relating to “predictive biomarker”, “neoadjuvant therapy” and “oesophageal adenocarcinoma” and screened as per the inclusion and exclusion criteria. All peer-reviewed full-text articles and conference abstracts were included. (3) Results: The search yielded 548 results of which 71 full-texts, conference abstracts and clinical trials were eligible for review. A total of 242 duplicates were removed, 191 articles were screened out, and 44 articles were excluded. (4) Discussion: Biomarkers were discussed in seven categories including imaging, epigenetic, genetic, protein, immunologic, blood and serum-based with remaining studies grouped in a miscellaneous category. (5) Conclusion: Although promising markers and novel methods have emerged, current biomarkers lack sufficient evidence to support clinical application. Novel approaches have been recommended to assess predictive potential more efficiently.

Systematic review with meta-analysis: prevalence of prior and concurrent Barrett's oesophagus in oesophageal adenocarcinoma patients

BACKGROUND

The proportions of patients with oesophageal adenocarcinoma (OAC) diagnosed by Barrett's oesophagus surveillance or with pre-existing Barrett's oesophagus are unclear.

AIM

To estimate the prevalence of prior and concurrent Barrett's oesophagus diagnosis among patients with OAC or oesophagogastric junction adenocarcinomas (OGJAC).

METHODS

We searched PubMed and Embase to identify studies published 1966-1/8/2020 that examined the prevalence of prior (≥6 months) or concurrent Barrett's diagnosis (at cancer diagnosis) among OAC and OGJAC patients. Random effects models estimated overall and stratified pooled prevalence rates.

RESULTS

A total of 69 studies, including 33 002 OAC patients (53 studies) and 2712 patients with OGJAC (28 studies) were included. The pooled prevalence of prior Barrett's oesophagus diagnosis in OAC was 11.8% (95% confidence interval [CI] 8.4%-15.6%). The prevalence of prior Barrett's oesophagus diagnosis was higher in single-centre resection studies (16.0%, 95% CI 8.7%-24.9%) than population-based cancer registry studies (8.4%, 95% CI 5.5%-11.9%). The prevalence of concurrent Barrett's oesophagus in OAC was 56.6% (95% CI 48.5%-64.6%). Studies with 100% early stage OAC had higher prevalence of concurrent Barrett's oesophagus (91.3%, 95% CI 82.4%-97.6%) than studies with <50% early OAC (39.7%, 95% CI 33.7%-45.9%). In OGJAC, the prevalence of prior and concurrent Barrett's oesophagus was 23.2% (95% CI 7.5%-44.0%) and 26.3% (95% CI 17.8%-35.7%), respectively.

CONCLUSIONS

Most patients with OAC have Barrett's oesophagus. Our meta-analysis found ~12% of OAC patients had prior Barrett's diagnosis, but concurrent Barrett's oesophagus was found in ~57% at the time of OAC diagnosis. This represents a considerable missed opportunity for Barrett's oesophagus screening.