• Asian Pacific Journal of Cancer Prevention
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• v.14 no.4
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• pp.2217-2220
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• 2013

Background: Knowledge regarding risk factors and primary signs of oral cancer in the general population can help them to avoid risky behaviour and seek timely advice from a physician. The aim of this study was to survey adult knowledge about risk factors and signs of oral cancer in Shiraz Dental University. Materials and Methods: In this descriptive cross-sectional study using an investigator-made questionnaire, 783 adults who were referred to Shiraz Dental University participated. Questionnaire data were analyzed by ANOVA and T-test. Results: The results showed that 32.3% of participants were aware of oral cancer and gained their knowledge from the media. The risk factors mentioned by these participants was as follows: sunlight 30.8%, hot and peppery food 40.7%, alcoholic drinks 47.4% and smoking 73.6% (there was significant relationship for drinking alcohol and gender, education and times of using dental service, p<0.05). They also mentioned the primary signs of oral cancer as follows: red patch without pain 27.8%, white patch without pain 13.5% and prolong scarring without pain 56.7% (there was significant relationship between these three signs and education and times of using dental service, p<0.05). The mean knowledge about the risk factors and signs of oral cancer were 1.94 from 5 with 1.14 standard deviation and 0.96 from 3 with 0.93 standard deviation. Conclusions: The observed low level of knowledge of people regarding both risk factors and signs of oral cancer emphasizes the need for more efforts to be made about the above mentioned issues by the media.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.6
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• pp.3619-3623
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• 2013

Background: The scientific evidence relating to the burden of oral diseases attributable to tobacco use has been reviewed and the need for a well-structured dental teaching program concentrating on oral cancer education and tobacco cessation interventions has been emphasized. The aim of our study was to evaluate the awareness of oral cancer and perception of tobacco use cessation counseling among dental students at all study levels in India, Saudi Arabia, the United Arab Emirates, and Yemen. Materials and Methods: A structured, pre-tested, self-administered 15-item questionnaire was used to conduct a cross-sectional survey. Data analyses including percentages, frequency distributions and tests of chi-square were generated. Results: A total of 621 (97.6%) Indian, 493 (96.5%) Saudi, 194 (96.5%) Yemeni and 187 (98.4%) United Arab Emirates respondents recognized the association between oral cancer and cigarette smoking. Although more than 96% of the students surveyed recognized the association between oral cancer and cigarette smoking and about 55% reported cigarette smoking as one of the etiological factors of oral cancer, more than 66% of students who reported cigarette smoking as an etiological factor of oral cancer disagreed/strongly disagreed with all the statements concerning tobacco use cessation. Conclusions: A higher level of oral cancer awareness did not have a positive impact on the perception of tobacco use cessation counseling among the sample surveyed.

• Environmental Mutagens and Carcinogens
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• v.19 no.1
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• pp.46-55
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• 1999

To develop a chemopreventive strategy based on the different stages of premalignant lesions, we hypothesized that the inhibitory effect of chemopreventive agents is influenced by different promotion stages during carcinogenesis. DMBA-TPA-induced skin carcinogenesis was used with ICR mice and chlorophyllin (CHL) was applied as a chemopreventive agent. In vitro assay was performed with Salmonella typhi. TA100 to observe any anti-mutagenic activity of CHL against DMBA. Pre-initiation and pre-promotion effects of CHL were observed by CHL treatment before initiation and before promotion. To evaluate the inhibitory effect at different promotion stages, each group was divided into three subgroups after TPA promotion for 6, 18 and 24 weeks, respectively ; the first subgroup was immediately sacrificed after termination of TPA, the second subgroup was treated with CHL, and the third subgroup was sacrificed 8 weeks after termination of TPA without CHL treatment. The degrees of epithelial dysplasia, papilloma formation, and invasive carcinoma were observed histologically, and GST-Pi expression was observed immunohistochemically. ODC mRNA level was analyzed by reverse transcriptase-polymerase chain reaction. Results showed : CHL dose-dependently inhibited the mutation of Salmonella typhi. TA100; the incidence of epithelial dysplasia and papilloma formation was lower in pre-initiation and pre-promotion CHL-treated mice than DMBA-TPA-treated mice; no invasive carcinoma developed in pre-initiation CHL-treated groups, while 67% of DMBA-TPA treated mice had carcinomas; GST-Pi expression decreased when CHL was treated before initiation and before promotion; and when CHL was treated after termination of TPA application at 18 and 24- week-TPA promotion stages, respectively, the incidence of epithelial dysplasia and papilloma was markedly reduced compared to non-treated groups. When comparing the incidence of epithelial dysplasia and papilloma between the immediately-sacrificed subgroup and the non-treated group with a waiting period, we speculated that the 18-week-TPA promotion stage might belong to the promoter-independent progression stage. At the 18-week-TPA promotion stage, the level of ODC mRNA in the CHL-treated group was clearly reduced to the level of normal tissue. Taking these results together, CHL showed both anti-initiation and anti-promotion effects, while the inhibitory effect of CHL was prominent in the 18-week-TPA promotion stage. However, CHL seems to be incapable of completely blocking the progression in the 24-week-TPA promotion stage.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.1
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• pp.189-195
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• 2016

Oral tongue squamous cell carcinoma (OTSCC) is the most common oral cancer subtype with a maximum propensity for regional spread. Our objective was to study if p53 expression might have any correlation with aggressive patterns of invasion within oral tongue cancers as well as with the histologically identified degree of oral tongue dysplasia. p53 immunoexpression was studied using immunohistochemistry in early staged OTSCCs (n=155), oral tongue dysplasias, (n=29) and oral tongue normal specimens (n=10) and evaluated for correlations with histological and clinicopathological parameters. Our study (n=194) showed a pattern of p53 expression increasing with different grades of tongue dysplasia to different grades of invasive OTSCC (p=0.000). Among the OTSCC tumours, positive p53 expression was seen in 43.2% (67/155) and a higher p53 labelling index was significantly associated with increased Bryne's grade of the tumour invasive front (p=0.039) and increased tumour depth (p=0.018). Among the OTSCC patients with tobacco habits, (n=91), a higher p53 labelling index was significantly associated with increased risk of local recurrence (p=0.025) and with lymphovascular space involvement (p=0.014). Evaluation of p53 through varying degrees of dysplasia to oral tongue cancer indicates that p53 expression is linked to aggressive features of oral tongue cancers and tongue precancers entailing a closer monitoring in positive cases. Among the OTSCCs, p53 expression is associated with tumour aggressiveness correlating with increased grading of invasive tumour front and tumour depth.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.15
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• pp.6193-6200
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• 2015

Head and neck cancer, including oral cancer, is the sixth most common cancer in humans worldwide. More than 90% of oral cancers are of squamous cell carcinoma type. Recent studies have shown a strong relationship between human papillomavirus (HPV) infection and head and neck cancer, especially oropharyngeal squamous cell carcinoma (OPSCC) and oral squamous cell carcinoma (OSCC). Moreover, the incidence of HPV-related OSCC appears to be on the rise while HPV-unrelated OSCC tends to have stabilized in the past decades. p16, a tumor suppressor gene, normally functions as a regulator of the cell cycle. Upon infection with high-risk types of HPV (HR-HPV), particularly types 16, 18, 31, 33, 34, 35, 39, 51, 52, 56, 58, 59, 66, 68, and 70, the expression of p16 is aberrantly overexpressed. Therefore, the expression of p16 is widely used as a surrogate marker for HPV infection in head and neck cancer.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.7
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• pp.3017-3020
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• 2014

Background: Oral carcinoma is one of the common types of cancer and one of the 10 leading causes of death around the world. This study was conducted to evaluate senior dental student knowledge about oral cancerous lesions in Zahedan Dental School. Materials and Methods: In this cross-sectional research, all the students in the last academic year at the School of Dentistry were studied during year of 2013. The study questionnaire covered demographic data as well as 12 questions concerning the knowledge of oral cancer. Data were collected and analyzed with SPSS18 using independent t-test, one way ANOVA. Significance level was considered as $p{\leq}0.05$. Results: Of the 104 senior dental students, with an average age of $27.34{\pm}7.79$ years, who participated in this study, 32 (30.8%) were female and 72 (69.2%) were male. The mean score of the students regarding the knowledge of oral cancer was $7.24{\pm}2.61.20$ students (19.2%) had a weak knowledge, 45 students (43.3%) had a moderate knowledge, and 39 students (37.5%) had a good knowledge. Conclusions: The student knowledge of oral cancer is not satisfactory and they need to receive additional information and education.

• Journal of Cancer Prevention
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• v.21 no.2
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• pp.88-94
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• 2016

Background: Breast cancer is the most common malignant disease in women. The patients with advanced breast cancer develop metastasis to bone. Bone metastasis and skeletal-related events by breast cancer are frequently associated with the invasiveness of breast cancer cells and osteoclasts-mediated bone resorption. Forsythia koreana is used in oriental traditional medicine to treat asthma, atopy, and allergic diseases. The aim of this study was to evaluate the inhibitory effects of F. koreana extracts on the invasion of breast cancer cells and bone resorption by osteoclasts. Methods: Cell viability was measured by an MTT assay and the migration and invasion of MDA-MB-231 cells were detected by a Boyden chamber assay. The formation of osteoclasts and pit was detected using tartrate-resistant acid phosphatase staining and calcium phosphate-coated plates, respectively. The activities of matrix metalloproteinases (MMPs) and cathepsin K were evaluated by gelatin zymography and a cathepsin K detection kit. Results: The fruit and leaf extracts of F. koreana significantly inhibited the invasion of MDA-MB-231 cells at noncytotoxic concentrations. The fruit extract of F. koreana reduced the transforming growth factor ${\beta}1-induced$ migration, invasion and MMPs activities of MDA-MB-231 cells. In addition, the fruit, branch, and leaf extracts of F. koreana also inhibited the receptor activator of nuclear factor kappa-B ligand-induced osteoclast formation and osteoclast-mediated bone-resorbing activity by reducing the activities of MMPs and cathepsin K. Conclusions: The extracts of F. koreana may possess the potential to inhibit the breast cancer-induced bone destruction through blocking invasion of breast cancer cells, osteoclastogenesis, and the activity of mature osteoclasts.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.10
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• pp.5087-5090
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• 2012

Oral cancer is a common site of head and neck cancer, and is relatively frequent in Northeast Thailand. The objective of this hospital-based, case-control study was to determine associations with risk factors. A total of 104 oral cancer cases diagnosed between July 2010 and April 2011 in 3 hospitals were matched with control subjects by age, sex and hospital. Data were collected by personal interview. There were significant associations between oral cancer and tobacco smoking (OR=4.47; 95%CI=2.00 to 9.99), alcohol use among women (OR=4.16; 95%CI=1.70 to 10.69), and betel chewing (OR=9.01; 95%CI=3.83 to 21.22), and all three showed dose-response effects. Smoking is rare among Thai women (none of the control women were smokers), but betel chewing, especially among older women, is relatively common. We did not find any association between practicing oral sex and oral cancer.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.9
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• pp.5461-5465
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• 2013

Oral cancer is one of the most commonly occurring cancers worldwide, decreasing the patient's survival rate due to tumor recurrence and metastasis. Menadione (Vitamin K3) is known to exhibit cytotoxicity in various cancer cells but the present study focused on its effects on viability, apoptosis, epithelial to mesenchymal transition (EMT), anchorage independent growth and migration of oral cancer cells. The results show that menadione is more cytotoxic to SAS (oral squamous carcinoma) cells but not to non-tumorigenic HEK293 and HaCaT cells. Menadione treatment increased the expression of pro-apoptotic proteins, Bax and p53, with a concurrent decrease in anti-apoptotic proteins, Bcl-2 and p65. Menadione induced the expression of E-cadherin but reduced the expression of EMT markers, vimentin and fibronectin. Menadione also inhibited anchorage independent growth and migration in SAS cells. These findings reveal and confirm that menadione is a potential candidate in oral cancer therapy as it exhibits cytotoxic, antineoplastic and antimigratory effects besides effectively blocking EMT in oral cancer cells.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.13
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• pp.5439-5444
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• 2015

Background: One of the main causes of delay in diagnosis of oral cancer is lack of awareness about aetiology and symptoms among the general population. The aim of this study was to assess the knowledge and practice of patients regarding oral cancer and their attitude towards tobacco cessation. Materials and Methods: This study was carried out in Isfahan-Iran in 2014. A 29-item self-administrated questionnaire was designed and piloted and distributed to patients attending dental clinics. Questions were focused on awareness about oral cancer risk factors, signs and symptoms, places in the mouth which are more susceptible and attitude toward tobacco cessation. Chi-square, T-test, ANOVA and logistic regression tests were used for statistical analysis. Results: A total of 546 valid completed questionnaires were obtained. The mean knowledge score of patients was 4.1(${\pm}2.7$) out of 13. Some 80% of patients did not know about early manifestations of oral cancer. Only 18% knew the most likely sites of oral cancer. Only 43.1% and 65.2% of patients reported alcohol and tobacco consumption as the main risk factors but they had a fair knowledge about other risk factors. There was no significant difference in Knowledge level between patients regarding their sex, educational levels and age. Most patents (90%) expected their dentists to warn them about the harmful effects of smoking and showed willingness to quit if recommended. Conclusions: Knowledge about oral cancer was found to be quite low. It seems necessary to increase the level of public awareness using educational programs with cooperation of dentists in tobacco cessation programs.