Oral field cancerization: an update on current concepts (original) (raw)
Related papers
Concepts in Understanding Oral Field Cancerization: A Brief Review
Indian Journal of Dental Advancements, 2017
The concept "field effect in cancer" originated in 1953, from the histopathological observations of Slaughter and colleagues regarding the occurrence of multiple primary oral squamous cell carcinomas and their local recurrences. There are two fundamental theories regarding the development of oral field cancerization (OFC) which includes the "classical" and the "clonal" mechanism. The classical view hypothesizes that the entire epithelial surface of the upper aerodigestive tract has an increased risk for the development of premalignant disorders because of multiple genetic abnormalities in the whole tissue region; owing to prolonged exposures of susceptible carcinogens as a result of tobacco or alcohol consumption. While the clonal theory believes that there always exists a field with genetically altered cells having a high risk of developing premalignant and malignant disorders. Here, the developing separate tumors from a genetically individually altered stem cell in the extended field, share the same clonal origin, and some degree of genetic similarity. Modern molecular and histological technologies exploring the tissue abnormalities in OFC have been performed. Herein, we have briefly discussed regarding the concepts of field cancerization along with the various diagnostic molecular techniques and the therapeutic aspects.
Cancer stem cells and field cancerization of Oral squamous cell carcinoma
Oral Oncology, 2015
Oral squamous cell carcinoma (OSCC) has a high propensity for local failure, which is attributed to recurrence at the primary site or the development of second primary tumors (SPT). Field cancerization that refers to the existence of transformed cells in areas adjacent to the primary tumor, has been attributed to be one of the probable reasons underlying disease relapse. The carcinogenic process necessitates multiple molecular events for the transformation of a normal cell into a cancer cell. This implies that only the long-time residents of the epithelium, such as the stem cells, might be the candidates capable of accumulating these genetic hits. These transformed stem cells-the 'Cancer stem cells' (CSCs), are further known to be equipped with the properties of tumor initiation and migration, both of which are essential for orchestrating field cancerization. The concept that the CSCs might be responsible for field cancerization in OSCC has not been explored extensively. If the role of CSCs as the primary units of field cancerization process is established, their presence in the mucosa adjacent to the tumor may be an indicator for local recurrence and/or development of second primary tumors. In this review, we examine the available evidence in literature exploring the possibilities of CSCs driving the process of field cancerization and thereby being the underlying mechanism for disease recurrence and development of SPT.
Oral cancer stem cells - properties and consequences
Journal of applied oral science : revista FOB
Research on cancer stem cells (CSCs) has greatly increased in the field of medicine and pathology; however, some conceptual misunderstandings are still present among the public as well as within the general scientific community that is not yet familiar with the subject. The very first problem is the misinterpretation of CSCs as a synonym of their normal counterparts, the well-known stem cells (SCs). Particularly in Dentistry, another common mistake is the misinterpretation of oral CSCs as normal tooth-derived SCs. The present review aims to clarify important concepts related to normal SCs and CSCs, as well as discuss the relevance of CSCs to the development, metastasis and therapy resistance of oral squamous cell carcinoma.
International Journal of Scientific and Research Publications (IJSRP), 2018
The incidence of oral cancer is increasing dramatically over the past years. According to National Cancer Registry Programme of Indian Council of Medical Research(ICMR), the mortality rate due to cancer has increased by approximately 6% between 2012 and 2014. The long term survival rates of oral cancer is less than 50%. Increased rate of morbidity and mortality is mainly due to the occurrence of multiple primary tumors and locally recurrent cancers. The concept of "field cancerization" by Slaughter et al. explains the mechanism by which second primary tumors develops. The presence of a 'field' with genetically altered cells appears to be a continuous risk factor for cancer. Detection and monitoring of these fields may have profound implications for cancer prevention. Here is a case report of "field cancerization" phenomenon.
Dental Journal
Background: Oral cancer therapy, such as radiation or surgical treatment, has pernicious long-term effects that patients suffer throughout their life, the disability being considerable with delayed diagnosis. It is well known that many oral cancers develop from oral potentially malignant disorders (OPMDs). Patients diagnosed with OPMDs may have an increased risk of developing cancer anywhere in the oral cavity. Early detection and intervention could be essential prevention strategies to inhibit oral cancer progression. OPMDs may not immediately develop into carcinoma. However, this condition provides a “field” of specific abnormalities wherein evolving altered genetic cells can be explained with the “field cancerization” concept. Purpose: This review aims to describe the “field cancerization” concept in oral cancer and OPMD, which is expected to contribute to a better clinical management strategy for oral cancer prevention. Review: “Oral field cancerization” describes oral cancers t...
Putative cancer stem cells are present in surgical margins of oral squamous cell carcinoma
Journal of B.U.ON. : official journal of the Balkan Union of Oncology, 2018
PURPOSE Recent evidence suggests that small subpopulations of stem-like cells are accountable for tumour initiation, progression and metastasis. Until now, studies were focused exclusively on the characterization of these cell populations within the tumour itself, while tumour margins were neglected, although it is known that the histological and molecular status of tumour margins may play a significant role in the course of the disease. Therefore, the aims of the study were to isolate cells from oral squamous cell carcinomas and their respective margins, to characterize these cells using specific markers, to assess their self-renewal potential and determine their chemoresistance. METHODS Cell cultures were obtained from 12 tissue specimens (6 tumours and 6 margins). Total RNA was extracted and gene expression analysis was done by real-time PCR (RT-PCR). Flow cytometry, immunocytometry, sphere formation and MTT assays were also applied. RESULTS With minor differences, cells originat...
Oral squamous cell carcinoma in relation to field precancerisation: pathobiology
Cancer Cell International, 2013
Squamous cell carcinoma of the oral cavity evolves within a field of precancerized oral epithelium containing keratinocytes at different stages of transformation. Following acquisition of additional genetic alterations, these precancerous keratinocytes may become cancerous. Persons with apparently successfully treated oral squamous cell carcinoma are at high risk of developing a new carcinoma at, or close to the site of the treated tumour. This second carcinoma may have developed either from malignant keratinocytes left behind at surgery (recurrence), or from transformed keratinocytes within the field of precancerized epithelium from which the primary carcinoma had arisen (new carcinoma). The cells of the new carcinoma may have genetic changes in common with the cells of the original carcinoma because both are descended from a proliferating monoclone within the precancerized field; but if the new cancer originates from a different clone, it may have a dissimilar genetic profile even if the original and the new carcinoma are closely contiguous. The purpose of this article is to review the pathobiology of oral squamous cell carcinoma in relation to fields of precancerised oral epithelium.
Comparative evaluation of genetic assays to identify oral pre-cancerous fields
Journal of Oral Pathology & Medicine, 2008
BACKGROUND: Oral squamous cell carcinomas often develop in a pre-cancerous field, defined as mucosal epithelium with cancer-related genetic alterations, and which may appear as a clinically visible lesion. The test characteristics of three genetic assays that were developed to detect pre-cancerous fields were investigated and compared to histology. METHODS: In total, 10 pre-cancerous fields that were not visible at clinical inspection and gave rise to malignant transformation based on an identical TP53 mutation in tumor and mucosal epithelium in the surgical margin, as well as 10 normal oral mucosa specimens were analyzed for numerical chromosomal changes with multiplex ligation-dependent probe amplification (MLPA), for loss of heterozygosity (LOH), with microsatellite PCR and for DNA index alterations with DNA image analysis. RESULTS: No alterations were detected in normal tissue by either of the assays. Both MLPA and LOH assays detected all pre-cancerous fields. DNA cytometry identified aneuploidy in four of 10 pre-cancerous fields, while the corresponding tumors that developed in these fields were shown to be aneuploid. CONCLUSIONS: Both the MLPA and LOH assay seem suitable for screening pre-cancerous fields in subjects at high risk for oral cancer even in the absence of clinically abnormal appearing oral mucosa. Measurements of DNA index might be valuable to determine the time to progression. Identification of oral pre-cancerous fields Bremmer et al. 600 J Oral Pathol Med Identification of oral pre-cancerous fields Bremmer et al. 604 J Oral Pathol Med Identification of oral pre-cancerous fields Bremmer et al.
Cancer stem cell and its niche in malignant progression of oral potentially malignant disorders
Oral oncology, 2017
The purpose of this study was to determine association between cancer stem cells (CSCs) and their niche with progression of oral potentially malignant disorders. Patients with histologically confirmed oral potentially malignant disorders, stratified into high/low risk lesions based on the degree of dysplasia and oral cancer were included in this study. Immunohistochemical profiling of markers of CSCs (CD44), endothelial cells (CD31) and CSC-vascular niche cross-talk (CXCR4 and SDF1) were carried out. Statistical analysis was performed to correlate the relationship of markers with histopathology grade (ANOVA, and χ2 test, unpaired t test) using GraphPad InStat v3.06. The study included 550 samples (349 patients) and analysis showed progressive increase in expression levels of CSC and its niche markers with increase in grade of dysplasia as compared to the normal cohort (p < 0.05). Co-expression analysis revealed that, in comparison to the normal cohort, a larger percentage of pati...