Search

Background: Oral cancer is a major health hazard worldwide with increasing incidence and mortality. Cervical lymph node metastasis is a major determinant of outcome in oral cancer. The matrix metalloproteinase (MMP) system is critically involved in invasion and metastasis. Assessment of MMPs and tissue inhibitors of MMPs (TIMPs) in certain combinations might have better clinical efficacy given their potential role in the metastatic process., Aim: Plasma concentrations of MMP-2, MMP-9, TIMP-1 and TIMP-2 in 50 controls and 75 oral cancer patients (nonmetastatic, n=54; metastatic, n=21) were evaluated to assess their investigative value and role in predicting the behavior of this malignancy., Methods: The plasma concentrations of MMP-2, MMP-9, TIMP-1 and TIMP-2 were quantified by ELISA. The best 2- and 3-marker combinations were calculated using the statistical software mROC. The diagnostic values for all the biomolecules as single markers and their combinations were estimated using the measures of diagnostic accuracy, i.e. the area under the ROC curve and the sensitivity and specificity at cutoff limits with the highest diagnostic accuracy and at the 95% limits of sensitivity and specificity, respectively., Results: MMP-9, TIMP-1 and TIMP-2 were significantly elevated (p=0.000, p=0.013 and p=0.005, respectively) in oral cancer patients. MMP-9 emerged as the best single statistically significant marker in plasma for oral cancer detection. It showed an increase in diagnostic performance when tested in combination with MMP-2 and TIMP-2. The median plasma MMP-9 levels were elevated in both the metastatic and nonmetastatic groups compared with controls (p<0.004 and p<0.007, respectively)., Conclusion: The results indicated that plasma MMP and TIMP levels in relevant combinations may facilitate clinical decisionmaking for improved management of oral cancer patients and may provide important data for selecting patients for treatment with drugs that interfere with MMP and TIMP activities.

Objective: To analyze chromosomal aberrations (CA) as an index of DNA damage, to measure DNA repair capability using mutagen sensitivity assay and to correlate tobacco exposure with CA., Study Design: Oral cancer patients, healthy tobacco chewers and healthy tobacco nonusers were studied for spontaneous and mutagen-induced CA. An arbitrary unit obtained for lifetime tobacco exposure (LTE) was compared with CA., Results: Mean levels of spontaneous and mitomycin-C-induced CA were higher in patients as compared to chewers and controls. DNA repair capability of patients was significantly deficient (p < or = 0.016) as compared to that of chewers. LTE was significantly higher (p = 0.004) in patients than chewers. Chewers having high LTE and spontaneous CA above cutoff levels might be at a greater risk of oral carcinogenesis., Conclusion: There is a probable risk of oral carcinogenesis in healthy tobacco consumers having higher CA and LTE. Whether the deficient DNA repair capacity of oral cancer patients is due to the disease process or the tobacco exposure needs to be confirmed with a larger population study.

Background: Multiple marker accumulation impacts tumor progression and biologic phenotypes affect clinical outcome of patients with head and neck cancer. Hence, this study investigated a battery of molecular markers that may help to reflect biologic aggressiveness and predict prognosis., Methods: Epidermal growth factor receptor (EGFR), Stat3, H-ras, c-myc, p53, cyclin D1, p16, Rb, Ki-67, and Bcl-2 were localized immunohistochemically in 135 oral squamous cell carcinoma patients to assess prognostic value., Results: In univariate analysis of total patients, p53, Stat3, and p16 predicted both relapse-free survival (RFS) and overall survival (OS). In Cox multivariate analysis, after adjusting for tumor size, nodal status, and lymphatic permeation, p53 was independently associated with RFS and OS, and p16 with RFS only. In only early-stage patients, in univariate analysis, nuclear Stat3 was significant for RFS and OS., Conclusion: Immunostaining of p53, p16, and Stat3 might serve as potential adjuncts in pathologic evaluation of oral tumors to predict risk of relapse.

Background: Oral cancer is the leading malignancy in India. Nitric oxide and antioxidant enzymes play an important role in etiology of oral cancer. Therefore, the present study evaluates nitric oxide and antioxidant enzyme levels in healthy individual without tobacco habits (NHT, N=30) and healthy individuals with tobacco habits (WHT, n=90), patients with oral precancers (OPC, n=15) and oral cancer patients (n=126)., Materials and Methods: Blood samples were collected from the subjects. NO2 + NO3 (nitrite+nitrate), superoxide dismutase (SOD) and catalase levels were estimated using highly specific spectrophotometeric methods. Statistical analysis was done by SPSS statistical software version 10., Results: Mean plasma NO2 + NO3 levels were elevated in patients with OPC and oral cancer patients as compared to the controls. Mean activities of erythrocyte SOD and catalase were higher in WHT than NHT. Erythrocyte SOD and catalase levels were higher in WHT and patients with OPC as compared to NHT. The erythrocyte SOD and catalase activities were lower in oral cancer patients than patients with OPC. The erythrocyte SOD activity was higher in advanced oral cancer than the early disease. Erythrocyte catalase activity was lower in poorly differentiated tumors than well and moderately differentiated tumors. Pearson's correlation analysis revealed that alterations in plasma NO2 + NO3 levels were negatively associated with changes in erythrocyte SOD activities., Conclusion: The data revealed that the alterations in antioxidant activities were associated with production of nitric oxide in oral cancer, which may have significant role in oral carcinogenesis.

Telomere attrition is an important event during tumorigenesis regulated by factors including oxidative stress, mitochondrial function, DNA adducts etc. Critically short telomeres act as signal for telomerase activity in the cancer cells. To determine whether null genotype of GSTM1 gene has any association with telomere length shortening and telomerase activity, we analyzed telomere length, telomerase activity and GSTM1 polymorphism in oral tissues. We observed that malignant tissues exhibited shorter telomere length. Telomerase activity was observed in about 75% malignant tissues. 40% of the oral cancer patients exhibited GSTM1 polymorphism. Further, shorter telomere lengths were observed in patients having GSTM1 polymorphism. Also, the GSTM1 genotype showed negative correlation with telomerase activity and telomere length. Our study proposes role of GSTM1 polymorphism in telomere attrition and subsequent telomerase activity in the cancer cells. The results are suggestive of possible link between absence of GSTM1 gene and telomere length alterations.

Background: The objective of the current study was to investigate the clinical usefulness of serum fucose, fucosylated glycoproteins (fucoproteins), fucosyltransferase (FucT), and alpha-L-fucosidase in oral carcinoma., Methods: Blood samples were collected from 130 patients with untreated oral cancer (OC), from 75 patients with oral precancerous conditions (OPC), and from 100 healthy controls. Cancer patients were followed after the initiation of anticancer treatments, and 75 follow-up samples were also collected. Serum levels of fucose and alpha-L-fucosidase were measured spectrophotometrically. Fucoproteins were detected by using lectin-affinity chromatography. FucT activity was analyzed by using radioassay., Results: Serum levels of fucose and fucoprotein were found to be increased significantly in patients with untreated OC compared with controls, patients with OPC, and complete responders (CR) to treatment; whereas the levels were comparable between untreated patients with OC and nonresponders (NR). A similar trend was observed for serum FucT levels, and changes in enzyme activity correlated well with fucose and fucoprotein alterations. The OPC group had significantly increased fucosylation of serum proteins. Furthermore, serum alpha-L-fucosidase activity was markedly higher in patients with untreated OC and in patients with OPC compared with controls. Using receiver operating characteristic curves, a cutoff for alpha-L-fucosidase was determined at >450.6 U/mL, which showed good sensitivity and specificity in OC and OPC compared with controls. The enzyme activity was declined in the CR group but remained higher in the NR group compared with pretreatment levels. Furthermore, various clinicopathologic characteristics were correlated positively with serum fucosylation changes., Conclusions: The findings of the current study suggest that serum fucosylation has clinical usefulness in the detection of early changes and for monitoring treatment response in patients with OC. Among the markers studied, serum alpha-L-fucosidase was identified as a useful marker for close monitoring of patients during post-treatment follow-up.

Increased sialylation of cell surface glycoconjugates is among the key molecular changes associated with malignant transformation and cancer progression. We investigated significance of linkage-specific sialylation changes in oral carcinogenesis. Tissue and serum levels of total sialic acid (TSA), linkage-specific sialyltransferases (ST) and sialoproteins were analyzed from patients with oral precancerous conditions (OPC) and oral cancer as well as the post-treatment follow-up blood samples of oral cancer patients. TSA levels were measured using a spectrophotometric method. The linkage-specific lectins, Sambusus nigra (SNA) and Maackia amurensis (MAM) detects alpha 2-6- and alpha 2-3-linked sialic acid, respectively, were used to analyze ST activity and sialoproteins. Malignant tissues showed significantly higher levels of TSA, reactivity of SNA and MAM, and alpha 2,3-ST activity compared to the adjacent normal tissues. alpha 2,6-ST was also higher in malignant tissues. Similarly, the marker levels were higher in precancerous tissues than their adjacent normal tissues. Serum levels of TSA, TSA/ total proteins, alpha 2-6-sialoproteins and alpha 2,6-ST were markedly increased in untreated oral cancer patients compared to the controls and OPC as well as responder (CR) patients. Serum levels of the markers were higher or comparable between untreated oral cancer patients and non-responders (NR). Serum levels of alpha 2-3-sialylation were elevated in non-responders compared with the responders. Further, the observed sialylation changes in tissue and serum were found to be associated with various clinicopathological features and disease progression. Thus, the data suggest potential utility of sialylation markers in early detection, prognostication and treatment monitoring of oral cancer.

Tobacco is the major etiological factor for oral cancer development through the generation of oxidative stress. Therefore, markers of oxidative stress such as total antioxidant status, lipid peroxidation, and total thiol levels might be useful to monitor oxidative stress and predict overall survival in oral cancer patients. The study included 140 oral cancer patients and 50 healthy controls, who were classified as with the habit of tobacco and no habit of tobacco. Adjacent normal and malignant tissue samples were collected from oral cancer patients. Plasma and tissue levels of lipid peroxidation, thiol, and total antioxidant status were assayed by spectrophotometric methods. Thiol levels were significantly lower in controls with the habit of tobacco (P= .033), oral cancer patients (P= .0001), and malignant tissues (P= .015) as compared to controls with no habit of tobacco, controls with the habit of tobacco, and adjacent normal tissues, respectively. Tobacco exposure was higher in oral cancer patients than controls with the habit of tobacco. Controls with the habit of tobacco who had lower thiol (odds ratio [OR]=10.58, P= .008) and high tobacco exposure (OR=0.251, P= .05) showed an elevated risk of oral cancer development. Patients showing a lipid peroxidation level above the cutoff level as compared to patients below the cutoff level showed poor overall survival, whereas those with thiol and total antioxidant status levels below the cutoff level as compared to their respective counterparts showed poor overall survival. In conclusion, lipid peroxidation and thiol could be useful for predicting the risk of oral carcinogenesis in healthy tobacco consumers and predicting overall survival of oral cancer patients.

Background: Factors that represent the potential for invasion and metastasis, such as matrix metalloproteinases (MMPs), could predict prognosis of cancer. Therefore, the authors studied plasma and tissue levels of MMP-2 and MMP-9 in oral cancer, the leading malignancy in India., Methods: Enzyme-linked immunosorbent assay and gelatin zymography were used for the MMP analysis from plasma and tissue samples, respectively., Results: Latent, active, and total forms and activation ratio of MMP-2 and MMP-9 were significantly elevated in malignant tissues as compared with adjacent normal tissues. Activation of MMP-2 was higher than MMP-9 in malignant tissues. Activation ratio was significantly higher in malignant tissues of the patients with lymph node metastasis as compared with those without lymph node metastasis (p = .005). Plasma MMP-9 levels were significantly lower in responders as compared with pretreatment levels (p = .002)., Conclusion: The data indicate that MMP-2 and MMP-9 can be useful to identify metastatic phenotype as well as for treatment monitoring in oral cancer., ((c) 2007 Wiley Periodicals, Inc. Head Neck, 2007.)

Objective: Oral cancer is the leading malignancy in India, with tobacco playing a major role in the etiology. The aim of the present study was to quantify nitrate+nitrite (NO2+NO3) in tobacco products as well as to study tobacco exposure related biomarkers in controls, patients with oral precancers (OPC) and oral cancer patients., Materials & Methods: Healthy individuals (n=90) were grouped into without habit of tobacco (NHT, n=30) and healthy individuals with habit of tobacco (WHT, n=60). Oral cancer patients with a tobacco habit were classified into abstinence (n=62) and non-abstinence (n=64) groups according to status at the study time. Urinary nicotine and cotinine levels were analyzed by modified high-pressure liquid chromatography (HPLC) using a UV detector. Levels of NO2+NO3 in tobacco and urine, and urinary thioether levels were estimated by spectrophotometry., Results: NO2+NO3 levels in different types of tobacco product ranged between 0.13 to 3.39 mg/g. The Odds Ratio (OR) analysis indicated positive associations of both smoking and chewing habits of tobacco with high risk of development of oral cancer. Urinary nicotine, cotinine and NO2+NO3 levels were significantly elevated in WHT, patients with OPC and oral cancer patients as compared with the NHT group. This was also the case for urinary thioether levels. Levels of urinary nicotine and cotinine were also higher in the non-abstinence group with oral cancers., Conclusion: The results confirmed that tobacco chewing and smoking habits are prominent risk factors for development of oral cancer in the western part of India (Gujarat). Urinary nicotine, cotinine, NO2+NO3 and thioether levels can be helpful for screening programs for oral cancer.

Aim and Background: The incidence and mortality due to oral cancer have increased worldwide. In India, the use of tobacco has been found to be the major etiological factor for the development of oral cancers. Various studies on serum p53 antibodies have suggested their clinical importance as prognostic markers in cancer. However, there is a dearth of data on serum p53 antibodies in oral cancer patients in India. The present study was carried to evaluate the clinical significance of serum p53 antibodies in oral cancer., Materials and Methods: The serum p53 antibody status was analyzed by means of ELISA in 55 healthy individuals, 60 patients with oral precancerous conditions, 75 untreated oral cancer patients, and 86 follow-up blood samples of the oral cancer patients., Results: We found serum p53 antibodies in 23% of cancer patients. The frequency of p53 antibody positivity was higher in patients with lymph node metastasis, advanced disease and well-differentiated tumors. Furthermore, p53 antibody positivity strongly correlated with poor treatment outcome in cancer patients. Kaplan-Meier survival analysis showed significantly poorer disease-free survival in patients with serum p53 antibodies., Conclusion: The results of this study suggest the usefulness of serum p53 antibodies in the prognostication of oral cancer patients.

Background and Objectives: Oral cancer accounts for one third of all malignancies in India where habit of tobacco consumption is the major etiologic factor, which causes field cancerization in oral mucosa. Multiple molecular events in oral mucosa due to field cancerization may be the cause of local and regional lymph node involvement in oral cancer resulting into low overall survival, high recurrence rate, and poor prognosis. Several matrix metalloproteinases (MMPs) have been shown to play an important role in the invasion and metastasis of oral squamous cell carcinoma (SCC). MMP-2 and MMP-9 are capable of degrading type-IV collagen, which is a major component of basement membrane. Therefore, we studied MMP-2 and MMP-9 activation by gelatin zymography, which is cost effective alternate to ELISA method, in patients with oral SCCs to predict their role in metastatic potentials., Materials and Methods: Thirty-nine patients of oral SCCs were classified as non-metastatic (n = 28), and metastatic (n = 11) according to regional lymph node involvement. Malignant and adjacent normal tissues of the patients were collected at the time of surgery. Gelatin zymography was carried out using 7.5% polyacrylamide gel under non-denaturing and non-reducing conditions. Zymograms were analyzed densitometrically. Latent and active forms of MMP-2 and MMP-9 were expressed as ng/50 microg of protein., Results: Latent and active forms of MMP-2 and MMP-9 were significantly elevated in malignant tissues as compared to their adjacent normal tissues (P < 0.05). Total MMP-2 and MMP-9 activities were also significantly elevated in malignant tissues as compared to adjacent normal tissues (P = 0.005 and P = 0.028, respectively). Activation ratio of MMP-2 and MMP-9 were significantly elevated in malignant tissues as compared to adjacent normal tissues. Activation of MMP-2 was prominent (11%) than MMP-9 (5%) in malignant tissues. Activation ratio of MMP-2 was significantly elevated in patients with lymph node metastasis than patients without lymph node metastasis (P = 0.005). Receiver's operating characteristic (ROC) curve analysis revealed that activation ratio of MMP-2 discriminate better than and activation ratio of MMP-9 between patients with and without lymph node metastasis. Activation ratio of MMP-2 could predict risk of lymph node metastasis development in patients without lymph node involvement., Conclusion: The study concluded that activation of MMP-2 and MMP-9 was significantly higher in malignant tissues as compared to adjacent normal tissues. Further, activation ratio of MMP-2 was significantly elevated in patients with lymph node metastasis as compared to patients without lymph node metastasis, which could predict risk of lymph node metastasis development in node negative patients.

Aim and Objective: Tobacco is a major etiological factor for oral cancer development, accounting 30-40% of all cancer cases in India. Tobacco consumption generates free radicals and causes oxidative damages. In order to counteract these lethal effects, normal living cells have multiple antioxidant defense systems in a cascade manner. Thus, it seems that studying biological parameters, like antioxidant enzyme system, may be helpful in risk assessment and early diagnosis of oral cancer. Therefore, we analyzed erythrocytic and tissue antioxidant enzyme activities in terms of glutathione-S-transferase (GST), glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and plasma thiol levels., Materials and Methods: Study included healthy controls with no habit of tobacco (NHT, n = 25), controls with habit of tobacco (WHT, n = 31) and oral cancer patients (n = 52). All the parameters were analyzed with highly sensitive and specific spectrophotometric methods., Results: Erythrocytic SOD and plasma thiol levels were significantly lower (p = 0.03), while GPx and CAT levels were higher (p = 0.017) in WHT as compared to NHT. No significant changes in GST and GR levels were observed between NHT and WHT. GST, GR, SOD and CAT activities were significantly higher (p = 0.05, p < 0.001, p = 0.003 and p < 0.001, respectively) while GPx and thiol levels were lower (p = 0.035 and p < 0.001, respectively) in oral cancer as compared to WHT. Odds ratio for erythrocytic GR, SOD, CAT and plasma thiol showed significantly higher risk of oral cancer development in WHT. Mean levels of SOD and CAT were increased, while GPx and thiol were decreased with the increase in habit duration in oral cancer. GST, GR and SOD activities were significantly higher (p = 0.0001, p = 0.005 and p = 0.005, respectively), while, CAT and thiol levels were lower (p = 0.0001 and p = 0.015, respectively) in malignant tissues as compared to adjacent normal tissues., Conclusion: The data revealed that evaluation of antioxidant enzyme activities and thiol levels in WHT can be helpful to identify individuals at a higher risk of oral cancer development, ((c) 2005 S. Karger AG, Basel.)

Background: Tobacco chewing is attributed to oral cancer. Prediction of cancer development by genotoxicity analysis is a major challenge to identify tobacco users at greater risk. Therefore, present study aimed to analyze tobacco related genotoxic effects in chewers monitoring micronuclei (MN) and chromosome aberrations (CA). The biomarkers were compared with non chewer to (i) predict risk for genotoxicity, (ii) estimate synergistic effect of tobacco exposure with level of biomarkers, and (iii) identify best cellular site of measurements for genotoxicity assessment. Methods: Healthy tobacco chewers (n=47); and controls (n=48) were enrolled in the study. The peripheral blood lymphocyte and exfoliated buccal mucosa cells were studied for CA and micro nucleated cell count (MNC) respectively. An arbitrary unit was obtained for Lifetime Tobacco Exposure (LTE) using frequency/day multiplied by duration of years of tobacco use. Data were analyzed using SPSS statistical software. Results: MNC was significantly higher (p=0.001) in chewers than controls. CA was higher in chewers than controls. MNC can differentiate higher tobacco exposure in chewers than CA. Controls having MNC above cutoff level have greater risk of genotoxic exposition (95% C.I.; 1.462-23.26, p=0.012). Conclusion: The present study concludes that MNC is a better surrogate biomarker to predict genotoxicity than CA for tobacco exposure and DNA damage index in tobacco chewers.

Background: Tobacco chewing is attributed to oral cancer. Prediction of cancer development by genotoxicity analysis is a major challenge to identify tobacco users at greater risk. Therefore, present study aimed to analyze tobacco related genotoxic effects in chewers monitoring micronuclei (MN) and chromosome aberrations (CA). The biomarkers were compared with non chewer to (i) predict risk for genotoxicity, (ii) estimate synergistic effect of tobacco exposure with level of biomarkers, and (iii) identify best cellular site of measurements for genotoxicity assessment. Methods: Healthy tobacco chewers (n=47); and controls (n=48) were enrolled in the study. The peripheral blood lymphocyte and exfoliated buccal mucosa cells were studied for CA and micro nucleated cell count (MNC) respectively. An arbitrary unit was obtained for Lifetime Tobacco Exposure (LTE) using frequency/day multiplied by duration of years of tobacco use. Data were analyzed using SPSS statistical software. Results: MNC was significantly higher (p=0.001) in chewers than controls. CA was higher in chewers than controls. MNC can differentiate higher tobacco exposure in chewers than CA. Controls having MNC above cutoff level have greater risk of genotoxic exposition (95% C.I.; 1.462-23.26, p=0.012). Conclusion: The present study concludes that MNC is a better surrogate biomarker to predict genotoxicity than CA for tobacco exposure and DNA damage index in tobacco chewers [ABSTRACT FROM AUTHOR]