Correlation of age and gender with the site of occurrence of oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is the most occurring cancer of the oral cavity showing changes based on-site, sex, age and habits of the population. The purpose of the study is to correlate the occurrence of oral squamous cell carcinoma at speci ic anatomical sites with age and gender. The present study is a retrospective study, including data from June 2019 to April 2020. Data of 50 OSCC patients including age, gender, site of the lesion, the onset of symptoms, treatment done, were collected, tabulated and then statistically analyzed. Results revealed that buccal mucosa was the most common site of occurrence inmales (61.50%): Correlation of gender with the location of oscc was statistically not signi icant with a p-value higher than 0.05. Regarding the association of age with a site of oscc occurrence, buccal mucosa was the common site of involvement in individuals below 50 years of age (54.50%), followed by tongue 23.50% and 21% in above 50 years of age. Correlation of age with the site of oscc occurrence was statistically insigni icant (p>0.05). Within the limits of the study, it can be concluded that the site of occurrence of OSCC is more governed by habits involved than age and gender itself. But an investigation involving a larger population would give a more comprehensive outcome.


INTRODUCTION
Oral squamous cell carcinoma (OSCC) is the most occurring malignancy of the oral cavity, showing geographical changes with respect to the sex site, age and habits of the population. Oral cancer is an important factor of mortality and morbidity worldwide which has an incidence rate that varies glob-ally by geographic location. OSCC is a signi icant health concern globally mainly in developing countries (Jayaraj et al., 2015a). Squamous cell carcinoma in India has a high incidence rate of 30-40% and has a high mortality rate (Jayaraj, 2015) . Oral cancer presents as a growth or sore in the mouth that does not disappear. Oral cancer which includes cancers of the lips, tongues, loor of the mouth, buccal mucosa, hard and soft palate, sinuses and pharynx, can be life-threatening if not diagnosed and treated early. While OSCC may arise de novo, most of the malignancy is contributed by the presence of clinically visible changes of oral mucosa which have a potential for malignant transformation (Sridharan et al., 2017) .
The high incidence of OSCC is also associated with increased tobacco usage (Shree, 2019). Tobacco is the leading risk factor for early death globally. Nearly sixty toxic chemicals present in tobacco can enter the body system and play a role in OSCC devel-opment (Jiang, 2019). Ankyloglossia has an association with congenital disorders like Van der Woude syndrome. Still, it has no signi icant role in OSCC development (Jangid, 2015) OSCC also has a high incidence for lymph node metastasis, because of rich lymphatic communications. This in luences the survival rate of OSCC patients with lymph node metastasis by decreasing the survival rate (Fan, 2011) . OSCC with lymph node involvement has high recurrence rates (Suresh, 2019) .
Recent studies on molecular genetics provide evidence that most of all head and neck squamous cell carcinomas start within a ield of pre-neoplastic cells (Gupta and Ramani, 2016). Subtypes of OSCC have been known to have a maximum propensity for regional spread (Viveka, 2016).
Salivary metabolomics has a signi icant role in identifying tumour speci ic biomarkers which provide insight regarding early tumour detection and progression (Sridharan, 2019). The purpose of the study is to correlate the occurrence of oral squamous cell carcinoma at speci ic anatomical sites with age and gender.

MATERIALS AND METHODS
This retrospective study covers the period from June 2019 -march 2020. n=50 cases of clinically con irmed cases of OSCC were selected. Ethical approval was given by the scienti ic review board of Saveetha Dental College and Hospitals, Chennai. Patient details including age, gender, lesion site, clinical diagnosis and treatment done were collected from DIAS (Data Integration and Analysis System). The number of people involved in the study was one guide, one researcher and one reviewer.
Dependent variables were age and gender of the patients and lesion site. Independent variables were habits, symptom onset, treatment done and follow up. Inclusion criteria were clinically con irmed cases of OSCC. Patients with no follow-up history were excluded from the study. Data veri ication of the patients was done by photographic veri ication retrieved from DIAS. All the data were entered and tabulated using Microsoft Excel 2016. Karl Pearson's chi-square test was done to identify the Correlation of age and gender with the site of OSCC occurrence using SPSS version 23 by IBM. P-value 0.05 was considered to be statistically signi icant.

RESULTS AND DISCUSSION
The study revealed that the most signi icant number of oscc develops in the fourth to ifth decade of life Figure 1, with standard prediction in males than females. Chi square analysis showing nosigni icance between age and site of occurrence of SCC. (p value = .177) Figure 2. Chi square analysis showing no significance between gender and site of occurrence of SCC.(pvalue= .590) Overall, the study result revealed that the common site for oscc occurrence was the buccal mucosa (40%) followed by the tongue (22%), retromolar region (16%), lower jaw (12%) and alveolus (10%) Figure 3. Karl Pearson's correlation coef icient was calculated to ind the degree of association between gender to the site of the lesion, age to the site of a lesion which was found to be statistically not signi icant (p>0.05).
The study result showed that occurrence of buccal mucosa in individuals above 50 years of age was common. Most patients in this study were in their 4th and 5th decades of life, which follows literature by (Shiboski et al., 2007). (Patel, 2011), showed a high incidence of OSCC among white female, young individuals in the age group of 18-44 years, indicating that there may be an increase in the emergence of head and neck cancers in young individuals due to tobacco usage. Considering all the oral anatomical sites, buccal mucosa was the most frequent site (40%), which is in accordance with the literature by (Salian, 2016) . (Tandon, 2017) , also states that the most common oscc site cases buccal in both men (59.5%) and women (40.4%) which is in accordance with our study. The frequency of OSCC lesions in this site has greater relevance to tobacco habit. 45.45% of females in our study were below 50 years of age, with no exposure to tobacco. Hence, genetic and hereditary assessment in patients with no association with tobacco should be done to get a conclusive result (Chandra, 2013) . The clinical data of the patients were veri ied by photographs obtained from DIAS, which emphasizes the role of dental photography (Hannah, 2018).
Followed by buccal mucosa, the tongue is the next common site to be affected (22%) in the age group above 50 years. Previous studies stated that the lateral border of the tongue is the most common site of OSCC among Europe and The United States population (Warnakulasuriya, 2009). Another study conducted by (Pires, 2013), also shows that the border of the tongue is the most affected anatomical site in the oral cavity. Oral tongue squamous cell carcinoma (OTSCC), a subtype of cancer is associated with poor therapeutic outcome and survival rates. OTSCC occurs due to extracellular matrix degradation and epithelial to mesenchyme transition (Thangaraj, 2016). In our study, it is found that buccal mucosa was the predominant site in men (40%) and also in age groups above 50 years age (22%). This variation in the site of oscc occurrence in age and gender groups could be contributed by lifestyle and cultural differences of different ethnic groups and also the biological mechanism of oscc development.
The striking feature in this study is that 60% of patients had no habits of tobacco usage. This inding is in accordance with the literature which states that in their study of 458 tongue cancer cases, 86.4% were never alcohol users and 49.3% of never tobacco users had the best survival outcomes which are not relevant to the earlier inding of cancer ive decades ago (Krishnamurthy and Ramshankar, 2013;Sivaramakrishnan and Ramani, 2015). Multinucleated giant cells form the main part of numerous bone, and soft tissue tumours were identi ied by using biomarkers like CD68, CD45 (Kumar, 2015) and use of biomarkers like these in OSCC might help in early detection of the disease progression. Reactive oxygen species have a signi icant role in the mitochondrial membrane damage-causing apoptosis (Gheena and Ezhilarasan, 2019). Viruses have long been described as one of the etiological factors for carcinogenesis, and there is growing evidence for the role played by human papillomavirus in OSCC (Jayaraj et al., 2015b). However, large scale study has to be done to substantiate the indings in our study (Swathy et al., 2015).
The epidemiological studies in oral cancer mostly are institutionally based, and sometimes gathering of patient information can be biased. The present study is online-based and has the same limitation. Lack of knowledge in retrospective studies is common. The study presents another limitation with the sample size of 50 OSCC cases. Unavailable data were not considered in the analysis of association and might have affected some of the indings. It is necessary to understand the importance of correct data collection along with records sent with the specimens, avoiding the loss of data to minimize this problem.

CONCLUSIONS
Within the limits of the study, we can conclude that buccal mucosa was the most common site of occurrence for oral squamous cell carcinoma among males and those greater than 50 years of age. Among the females, alveolus was found to be the most common site. Free screening camps, counselling of poor, uneducated people might help in early detection of oral squamous cell carcinoma. To get more promising results, the study must be conducted with an expanded sample size.

Funding Support
The authors declare that they have no funding support for this study.