Identification and Quantification of “Cancer Stem Cells” in Potentially Malignant and Malignant Disorders of Head and Neck Region: A Flow-Cytometric Study

Abstract

Background: Cancer stem cells (CSCs) are subpopulation of cells existent in a cancerous mass of cells. These CSCs hijack the properties of stem cells like self-renewal as well as being resistant to any conventional cancer therapies. The objective of this study was to identify and quantify the presence of these CSCs by using surface markers CD44, CD133, and ALDH1 among three groups of subjects who were age and gender matched (Normal controls, Oral cancers, Potentially malignant disorders). Methodology: This study was conducted in a sample of 108 subjects who were divided into three groups: Group I- Controls (C), Group II- Oral cancer (OC), Group III- Potentially Malignant Disorders (PMDs). Among them, 40 subjects each were present in Group I & II and 28 subjects were included in group III, and they were respectively diagnosed histopathologically as OC and PMDs. The identification of the sub-population of CSCs by means of above mentioned surface markers was done using Flow cytometry. Results interpretation: Non-parametric tests were applied. Median age limit was 59 years in group II, which was higher than Group I or Group III subjects. p-value was 0.002* which was significant. Group I included 19 females (47.5%) and 21 males (52.5%). In Group II, 18 subjects were females (45%) and 22 were males (55%), and in Group III, 17 subjects were females (60.7%) and 11 were males (39.3%). p-value was 0.409, which was not very significant. In group II, 23 subjects (57.5%) were in clinical stage 2, 11 (27,5%) were in clinical stage 1 and six (15%) were in clinical stage 3. Histopathologically in group II, 15 (37.5%) were in grade I, 20 (50%) were in grade II and five (12.5%) were in grade III. Results of the three groups were compared and correlated regarding the presence of cancer stem cells based on the surface markers CD44, CD133 and ALDH1. Unlike other similar studies, our study showed no statistically significant presence of CD44, ALDH1 positive cells, but only CD133 was slightly significant. Inference: The results of our study showed no statistically significant evidence in identification of the presence of cancer stem cells in the oral cancers as well as potentially malignant disorders based on the presence of surface markers.