Cancer stem cells in head and neck squamous cell carcinoma and its associated markers: A review.

ABSTRACT: Evidences of the current research say that cancer is multifactorial with varied mechanisms of origin. Most theories evolve either intrinsic (genetic) or extrinsic factors like tobacco and alcoholism as the major cause of oral cancer in India. There is growing evidence that human papilloma virus may act as a co-carcinogen, along with tobacco, in the causation of cancers. The cells being triggered by the agents may be somatic (differentiated functional cell) or a normal stem cell with multipotency or even the transient proliferative cells derived from the stem cells. These stem cells possess several features like slow cell cycle, ability to extrude chemotherapeutic drugs, exhibit epithelial mesenchymal transition, and inhibit apoptosis. Targeting these progenitor stem cells may aid in improving the overall prognosis of the patient. These cancer stem cells are targeted using various markers that are apparently more or less specific to various types of stem cells.

Does microbiome shift play a role in carcinogenesis? A systematic review.

Recent scientific advances have presented substantial evidence that there is a multifaceted relationship between the microbiome and cancer. Humans are hosts to multifarious microbial communities, and these resident microbes contribute to both health and disease. Circulating toxic metabolites from these resident microbes may contribute to the development and progression of cancer. The aim of this systematic review was to evaluate microbiome and microbial shift contribution to the development and progression of cancer. This systematic review provides an analytical presentation of the evidence linking various parts of the microbiota to cancer. Searches were performed in databases such as PubMed, Google Scholar, Scopus, EBSCO, E-Journals and Science Direct from the time of their establishment until May 2018 with the following search terms: cancer or human microbe or cancer and human microbiome AND shift in microbes in cancer. The merged data were assessed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Cochrane's Risk of Bias Tool was used to assess the bias. Initially, 2,691 articles were identified, out of which 60 full-text articles were screened and re-evaluated. Among them, 14 were excluded based on inclusion/exclusion criteria; eventually, 46 articles were included in the systematic review. The reports of 46 articles revealed that microbial shift involving Candida species, Fusobacterium nucleatum, Porphyromonas gingivalis, Helicobacter pylori and Human papilloma virus (HPV) 16 & 18 were most commonly involved in various human cancers. In particular, organisms, such as Candida albicans, Fusobacterium nucleatum, Porphyromonas gingivalis and HPV-16 were found to be more prevalent in oral cancer. The present systematic review emphasizes that the role and diverse contributions of the microbiome in carcinogenesis will provide opportunities for the development of effective diagnostic and preventive methods.

Cocktail of Periodic Acid-Schiff and Papanicolaou: Novel staining technique for the identification of leukemic eosinophils - A pilot study.

BACKGROUND: Tissue eosinophilia may be caused due to reactive, neoplastic or idiopathic reasons. Reactive eosinophils in allergic and inflammatory conditions are transient and recruited from the circulation in response to various stimuli, whereas neoplastic eosinophils of leukemias and hematological malignancies are involved in the pathogenesis of the disease. The differentiation of reactive from neoplastic eosinophils has a serious implication on the treatment and prognosis of diseases. However, both these types of eosinophils display variation in morphology and staining characteristics in routine histopathology leading to a diagnostic dilemma. AIM: The aim of this study is to evaluate the efficacy of special stains for the demonstration of eosinophils in normal/reactive lesions and leukemias. METHODOLOGY: A retrospective study comprising twenty histologically diagnosed cases each of reactive oral lesions and leukemias were obtained from institutional archives. These tissue sections were subjected to staining with routine and special stains - Carbol chromotrope, Congo red, Leishman's stain, Periodic Acid-Schiff-papanicolaou (PAS-PAP) and PAS. Statistical analysis was performed using Pearson's Chi-square test to compare the various parameters in the evaluation of the staining efficacy. RESULTS: Carbol chromotrope and Congo red staining showed increased staining efficacy in normal/reactive eosinophils while PAS-PAP followed by PAS and Leishman's stain showed enhanced features such as homogenicity, specificity, increased staining intensity, enhanced nuclear and cytoplasmic details in leukemic eosinophils. CONCLUSION: Combined PAS-PAP is a novel and cost-effective staining technique in differentiating reactive and leukemic eosinophils. It is significant in recognizing leukemic eosinophils of routine biopsies and alerts the clinician to rule out any underlying malignancies.