Can the epidemiological profile influence the clinical characteristics and malignancy of oral and oropharyngeal carcinomas?

Objective: the aim of this study was to analyze possible associations between the epidemiological variables of the study and the clinical stage and malignancy grade of squamous cell carcinomas (SCCs) of the oral cavity and oropharynx, and to evaluate whether there is a correlation between clinical stage and histological grade in SCCs. Material and Methods: retrospective analytical study of SCCs cases diagnosed between June 2005 and December 2013. The data from medical records and histopathological findings of patients over 18 years old were entered into an Excel® spreadsheet and analyzed by SPSS® 20, using the chi-square and Fisher’s exact tests to analyse the variables. The level of significance of the tests was 0.05. Results: patients were predominantly black, male, illiterate, in their sixth decade of life, living in country towns and exposed to tobacco and alcohol. There was also predominance of advanced-stage tongue lesions with high-grade malignancy treated with combined radiotherapy and chemotherapy treatment. There was association between exposure to alcohol with advanced stage at diagnosis (p=<0.001). Conclusion: association of alcohol consumption with more advanced lesions at diagnosis underscores the need to address the risk factors more emphatically. Although classic factors implicated in the course of oral and oropharyngeal SCC have been observed, it is remarkable the high frequency of illiterate patients coming from country towns, which could have hampered the access to health care and contributed to a delayed diagnosis and thus, to a poorer prognosis.


I
n Brazil, estimates for the year 2016 point to the occurrence of 600,000 new cases of cancer.The incidence of oral cancer is estimated to be around 11,140 new cases in men and 4,350 in women, and the oral cavity is the seventh most frequent site of occurrence of malignancies. 1 In Northeastern Brazil, there is an estimate of 3,070 new cases, and among them 170 cases will be in the state of Alagoas. 1 Despite the high incidence, there is limited knowledge of oral and oropharyngeal cancers by the population, physicians and dentists. 2mong the various histological types of malignant tumors that occur in this site, squamous cell carcinomas (SCCs) are the most frequent, accounting for over 90% of all oral cancer cases. 3ancer is a disease primarily caused by genetic changes that progress through a sequential series of somatic mutations in specific genes such as proto-oncogenes and tumor suppressor genes, resulting in uncontrolled cell proliferation. 4These events can be triggered by extrinsic and/or intrinsic factors such as lifestyle, environmental factors, immunosuppression and individual susceptibility.Among the extrinsic factors, smoking and alcohol consumption pose the greatest risks to the occurrence of such malignancy. 5][8] A useful tool for evaluating the prognosis of head and neck carcinomas is clinical staging using the TNM system, 9 in which tumors are classified into stages ranging from I to IV.It is well established that the head and neck SCCs classified as stage I have better prognosis than those at stage IV. 4,10,11owever, despite technological advances with research and methods to aid in the detection of oral lesions, nearly two-thirds of these cancers are still diagnosed in the advanced stages. 12CCs originate from a dysplastic surface of epithelium and is characterized histologically by invading the underlying connective tissue in the forms of islands and cords of tumoral cells.
Based on the histopathological features, gradation of SCCs may be performed using one of the various classification systems available. 4,11,13,14ryne grading system is one of the most widely used currently and it is based on evaluating the histopathologi-cal characteristics of the tumor's invasion front: degree of keratinization, nuclear pleomorphism, invasion pattern and inflammatory infiltrate.The scores assigned for each parameter are summed up, indicating the degree of tumor malignancy. 14,15he treatment of oral and oropharyngeal tumors includes surgery, radiation and chemotherapy with cisplatin.It has been observed that regardless the improvement of treatments, survival rates at 5 years remain low. 16ince oral and oropharyngeal cancer is a disease with high morbidity and mortality, the earlier the patient is diagnosed and treated, the smaller the sequelas and the greater the quality of survival.Knowledge of the cancer's stage may influence its prognosis.
Therefore, the aims of this study was to evaluate possible associations between epidemiological variables, clinical stage and Bryne malignancy grade in oral and oropharyngeal cancer as well to assess whether there is a positive correlation between clinical stage and histological grade in SCC cases.

Material and Methods
A cross-sectional and retrospective analytical study of a series of 84 cases of SCC of the mouth and oropharynx diagnosed in a reference Oral Diagnosis service and treated at a reference service, High Complexity Oncology Center (CACON) in Maceio, AL, Brazil.
The analysis included all the medical records and slides of patients aged 18 years or older, diagnosed from June 2005 to December 2013 and excluded the records whose lack of information would compromise the study results.
A form with epidemiological variables (age, sex, skin color, origin, level of education, occupation, smoking and drinking habits), clinical features, Bryne grading and treatment, was designed to collect data from medical records that met the inclusion criteria: have a histopathology diagnosis compatible with SCC and be diagnosed and treated at the participating services.
The staging of the lesions was performed according to the TNM system recommended by the International Union for Cancer Control (IUCC). 9After setting the categories T (size of the primary tumor), N (involvement of regional lymph nodes) and M (presence or absence of distant metastases), the stages were grouped in an increasing order of severity ranging from I to IV.
The patients' histopathological slides and blocks filed in anatomical pathology laboratories were selected to establish the histopathological grade of malignancy.The histopathological analysis was performed by light microscopy (Nikon microscope, model Eclipse E200) using 5-µm-thick histopathological sections and stained with hematoxylin and eosin (HE).From this analysis, the histopathological grade of malignancy in each case was defined following the Bryne system 17 for the tumor invasion front.The grading system evaluates four morphological parameters -degree of keratinization, nuclear pleomorphism, invasion pattern and lymphocytic infiltration, characterizing each one by scores ranging from 1 to 4, which define the degree of malignancy for each tumor.From the sum of the scores obtained for each parameter, the resulting total score is established as: 4-8 (grade 1 -low-risk lesions) and 9-16 (grade 2 -high-risk lesions).A high score suggests a highly undifferentiated tumor.Magnifications of 100x were used to analyze the degree of keratinization, invasion pattern and inflammatory infiltrate, and 400x to analyze nuclear pleomorphism.
Calibration of the two examiners was performed prior to the analysis of the histopathological slides.The Kappa coefficient evaluated inter-examiner agreement.The analysis of reliability revealed a Kappa greater than 0.80 with a 95% IC, indicating excellent correlation.
The information collected from the forms were transferred to an Excel database (Microsoft Corporation, USA) and analyzed using the SPSS ® 20 for Windows (Statistical Package for Social Sciences; IBM, USA).Descriptive analysis was performed by absolute and relative frequencies for categorical variables and measurements of central tendency for continuous variables.Chi-square and Fisher's exact tests were used for inferential analysis.The significance level for all tests was set at 0.05.
For analysis purposes, stages I and II were grouped into "early stage" and stages III and IV into "advanced stage".
The study was approved by the CESMAC University Center Ethics Committee (Protocol #367585/2013).

Results
Eighty-four medical records were included in the present study.Epidemiological data are shown in Table 1 and show a relationship of 2.36 affected males for every woman.Fifty-nine men (70.2%) and 25 women (29.8%) with mean age of 63.1 (±12.5) years and a median of 62.5 years, ranging from 38 to 95 years.Brown-skinned (38.1%) and black-skinned patients (39.3%) were similarly affected.Most patients came from countryside (59.5%) and were illiterate (72.6%).As much as 76 (90.5%) patients were exposed to smoking (smokers and former smokers) and 54 (64.3%) to alcohol abuse (alcoholics and former alcoholics) (Table 1).Lesions were more frequent in the tongue (26.2%), followed by the floor of the mouth (20.2%) and ulceration (64.3%) was the most frequent primary lesion.There was an association between exposure to alcohol and clinical lesion stage at diagnosis (p<0.05) with an odds ratio of 0.102 (95% CI 0.026 to 0.404).Among the patients exposed to alcoholism, 94.4% (Table 3) were diagnosed in advanced stages (III and IV).
No statistically significant correlation was found between the studied variables (epidemiological and clinical staging) and the Bryne malignancy grading (Table 4).
The most frequent TNM classifications were T2N1M0 (17.8%), followed by T3N1M0 (13%) and T3N0M0 (10.7%).Diagnosis at advanced stage was established in 83.3% of cases (45.2% in stage III and 38.1% in stage IV) and 16.7% of the cases at early stage (stage I, 3.6% and 13.1% in stage II).As to the malignancy grade, 49 cases (58.3%) were classified as high grade and 35 (41.7%) as low grade.

Discussion
Oral cancer is a public health problem and its occurrence has increased every year.SCC is the most frequent histopathological type in the oral cavity and, due to regional metastases, it presents a high mortality rate. 1 The results of this study reinforce the literature findings, which show the prevalence among patients in the fifth and sixth decades of life [16][17][18] and males. 7,8,14,18Souza and et al. 19 found an even higher percentage of affected males (92.8%).The difference in the male/female ratio diagnosed with oral and oropharyngeal cancer has declined in recent decades, 20 likely due to the greater exposure of women to carcinogenic agents, especially tobacco and alcohol.As shown in Chart 1, the skin color varies widely and a result of the different regions where the studies were performed and different degrees of miscegenation.
The geographical home location, whether urban center or countryside, has not be underscored in most studies.In the present study and in a similar one 8 from the same group of authors, it seems to be important finding, as the distance from urban centers increases the difficulty of access to diagnosis and treatment.In addition, the state of Alagoas has one of the lowest Human Development Index (HDI) in Brazil: 1 0.631 2 and 91.8% of the population depends on the assistance provided by the National Health System (SUS) 2 and are subjected to a long wait for scheduling consultation.
In 2012, the Brazilian population of illiterates aged 15 years and older was 13.2 million people.The Northeastern region concentrates more than half (54%) of the total illiterate population aged 15 or over in Brazil, a population of 7.1 million people.Among the states, Alagoas had the worst illiteracy rates, exhibiting 27.4% of the population unable to read or write. 22This study identified 72.6% illiterates, similar to other studies. 7,8The lack of education may be another factor that hinders the access of these patients to diagnosis and appropriate treatment, leading to a worse prognosis.The lack of statistically significant difference may be due to the high percentage of illiterate patients.
In the study by Santos et al., 8 62% of patients were inactive, retired or unemployed, higher than found in this study (42.9%).Few studies describe the patients occupation.In the study Santos et al., 7 39.2% were rural workers.
Borges et al. 23 observed was a relationship between socioeconomic status and oral cancer, showing that socially disadvantaged groups tend to have greater contact with risk factors (tobacco and alcohol), along with poor oral health and nutritional deficiencies.A systematic review of the literature 24 showed an association between low socioeconomic status and oral and oropharyngeal cancer, especially for those with low education, employees without specific skills or apprentices.
Among the harmful habits, smoking and alcoholism have been frequently pointed out as the main risk factors in the development of oral cancer, acting synergistically and increasing the incidence.Tobacco is a complete carcinogeni, able to cause irreversible changes at the structural and cellular levels in addition to causing mechanical injury.Alcohol has a local irritating effect, stimulating cell proliferation and mutagenic changes, and may indirectly cause depression of the immune system and nutritional alteration. 3The present study highlights the high percentage of patients exposed to smoking.Only 9.5% had not been exposed to tobacco, as ob-served in other studies. 8,14,17,25There was exposure to alcohol consumption by 64.3% of patients, similar to that found by other authors. 8,14,19here was an association between alcohol exposure and clinical stage of the lesion at diagnosis (p<0.05) in the present study.The lack of statistical association between exposure to smoking and clinical stage of the lesion at diagnosis (p=0.398) may be explained by the fact that almost the entire sample (90.5%) was exposed to tobacco.Gouvea et al. 4 showed that patients who reported concomitant history of tobacco and alcohol consumption presented a more advanced stage of disease at diagnosis, compared with the other groups.Likewise, it is believed that most patients in this study that were exposed to alcoholism were also exposed to smoking, and that the synergistic effect of these habits may have been associated with diagnosis at more advanced clinical stages.
The tongue was the most frequently affected site, corroborating the literature. 1,19Carvalho et al. 17 and Souza et al. 19 showed that lesions located in areas of difficult surgical access in anatomical areas of greater blood or lymphatic circulation (like the tongue) have worse prognosis and reported that the thicker the tumor the higher its TNM staging and the worse the evolution of the patient.
In their early stages, oral and oropharyngeal SCCs may present in the form of leukoplakia, erythroplakia or the combination of both, although ulcer is the classic fundamental lesion, which can be superficial, endophytic with high edges or exophytic. 3he oral cavity is an anatomical site of easy access for examination, allowing dentists, physicians or the patients themselves by self-examination, to identify lesions in their early stages, contributing to an early diagnosis.According to Santos et al., 8 erroneous early detection, lack of multidisciplinary work and communication inability among professionals from different levels of health care contribute to late diagnosis for patients with oral cancer.
Oral SCCs present a high healing rate (approximately 80%) up to the fifth year of disease for patients diagnosed in stage I (T1N0), while for stage IV the healing rate is only 20%. 7,8Early diagnosis has vital importance for patients with SCC of the mouth and oropharynx.Therefore, dentists have an important role in early detection and prevention of tumors.In this study, a significant number of cases were diagnosed in advanced stages, agreeing with other studies. 7,8The most frequent TNM classifications were T2N1M0 (17.85%) and T3N1M0 (13%).Santos et al. 7 found that most patients (78.4%) had more tumors classified as larger than T2N0M0 (stages III and IV), characterizing advanced disease.
The histopathological grade of the deepest margins of oral SCC influences directly the patient survival, since cancer cells in this site are undifferentiated and have a high Can the epidemiological profile influence the clinical characteristics and malignancy of oral and oropharyngeal carcinomas?prognostic value.The invasive areas may be primarily responsible for the clinical behavior of the tumor and this may be indispensible in choosing the treatment strategy for oral SCC. 10 Few studies have assessed the degree of tumor malignancy.In the present study, a significant percentage of the histopathological slides was classified as having a high degree of malignancy (58.3%).Patients with disease at advanced stage have a tendency to have histopathological injuries in the worst grades of malignancy and therefore worse prognosis.Costa et al. 10 showed association between TNM classification and histopathological malignancy scores (p=0.001).In the present study, statistical significance was not observed.
Regarding the treatment, in the state Alagoas there is great difficulty for NHS users to have access to head and neck surgeons, which leads most patients to be treated by radiotherapy combined with chemotherapy.Allied to this is the fact that many patients are diagnosed at advanced stages, when surgery is no longer indicated because the tumor cannot be resected or because of the patient's deteriorated clinical condition.
In the present study, 47.6% of the patients were treated by the combination of radiotherapy and chemotherapy, disagreeing from the studies by Carvalho et al. 17 and Bérquez et al. 18 in which the radiation combined with surgery was the most frequent treatment.Radiation was the most frequent treatment option (34%) observed by Santos et al. 8 Characterize a series of oral and oropharyngeal cancer allows enumerating epidemiological, clinical and histopathological findings that could, if correlated, point to factors that may indicate a worse prognosis.

Conclusion
In the present study it was observed an association between exposure to alcohol and tumor's clinical staging.More advanced lesions were diagnosed in patients exposed to both alcohol and smoking.This finding suggests the powerful synergistic effect of these two habits in the development of oral and oropharyngeal SCCs and reinforces the need to work more strongly on these risk factors.

Table 1 .
Distribution of frequencies of epidemiological variables of 84 patients with oral and oropharyngeal cancer Comparison between the profile of patients with oral and oropharyngeal cancer in the present study and in the literature Source: Alagoas, Brazil, 2005-2013.Chart 1 compares the results of the present study with those of others published over the last 5 years.RT: radiotherapy.CT: Chemotherapy.Source: Research Data / Santos et al., 2012; Carvalho, Santos and Figueiredo, 2012; Bórquez et al., 2011.; Ferraz et al., 2010; Santos Batista and Cangussu, 2010; Gouvea et al., 2010.* NEA -Not Economically Active

Table 3 .
Association between the study variables and the clinical stage

Table 4 .
Association between the study variables and Bryne histopathological grading of patients with oral and oropharyngeal cancer (n = 84 cases)