HistopatHological differences between genders in patients witH oral squamous cell carcinoma

Introduction: Oral cancer ranks fifth among the most frequent malignant tumors in men in Brazil. The incidence of this tumor among women has grown. It is still controversial whether gender can influence the outcome or the prognostic features of the disease. Objectives : To compare the histopathological features of oral squamous cell carcinomas between genders among patients undergoing surgical treatment in an oncological hospital of southern Brazil. Methods: Between 2007 and 2011, 404 patients underwent resection of malignant tumors of the oral cavity in the head and neck department of this institution. A subgroup of 209 previously untreated oral cavity squamous cell carcinoma cases was selected for comparative analysis. Results: In total, 68 participants were women and 141 were men. The tongue was the most common subsite in both genders. Men presented lower mean age and women presented tumors with smaller depth of invasion. Although among women it was observed a trend towards tumors with less aggressive characteristics, no other variable showed statistically significance. Conclusion: Women with oral tumors tend to present more superficial primary tumors and at a later age. Keywords: Oral neoplasms; carcinoma; squamous cell; prognosis

According to INCA estimates for the biennium 2016-2017 1 , oral cavity cancer represents around 3.6% of incident malignancies in Brazil.Despite its low representativeness, the incidence and mortality from oral cavity cancer has been growing over the years in Brazil, differently from what has been seen in developed countries 2 .Nowadays, this cancer ranks fifth among the most common malignant tumors in men in Brazil, reaching the fourth position in southeast Brazil 1 .The squamous cell carcinoma (SCC) remains the most common malignancy of the oral cavity.Alcohol intake and smoking remain the main risk factors for the disease in Brazil 1 .Apparently, the disparity in the reduction of alcohol and tobacco abuse among men and women seems to explain the increased incidence and mortality observed among female in some studies 3 , leading to a gradual reduction in the men:women ratio 1,4 .Although not included among the most incident malignancies of women in Brazil, about 28% of the new oral cavity cancers affect females in this country 5 .
Although current literature still lacks a consensus, there is a trend towards a better prognosis among women with oral cavity cancer [1][2][3][4]6 . Prgnostic variations observed between genders might be explained by clinical and pathological differences between men and women.This study aims to evaluate the histopathological features at initial presentation by analyzing a historical series of patients surgically treated for oral cavity squamous cell carcinoma in an oncological hospital of southern Brazil.

METHODS
With the approval of the Research Ethics Committee of the author's Hospital, a retrospective analysis was performed involving all patients undergoing resection of malignant tumors of the oral cavity between the years 2007 and 2011 by the Head and Neck Surgery Department of this institution.During this period, 404 patients had their data reviewed.Patients treated without curative intention, cases previously treated for other head and neck malignant tumors, patients with lip tumors and those with histopathological results different from SCC were excluded from the analysis.Age and histopathological characteristics were compared between genders.In total, 209 patients were included in the final analysis.
It was considered an exiguous margin equal or inferior than 2mm.The seventh edition of UICC staging system was used to classify the clinical stage as either early (I-II) or advanced (III-IV).Histopathological grading of the surgery specimens was performed according to the World Health Organization (WHO) grading system.Lymph-node metastasis was classified as present or absent.
Descriptive analysis was used to summarize data.Kolmogorov-Smirnov test was performed for assessing normality of continuous variables.Continuous variables were expressed in mean and standard deviation or median, minimum and maximum value, as appropriate.Categorical variables were expressed in relative and absolute frequencies.Authors used student's t-test in the comparison of age means; Mann-Whitney test in the comparison of size and depth of invasion medians; and the non-parametric chi-square test in the comparison of categorical variables.Statistical analysis was performed through software SPSS version 15.0 (SPSS Inc., Chicago, IL).All tests considered a significance level of 5%.

RESULTS
Tumors were distributed according to gender, histopathological characteristics and age, as demonstrated in Table 1.In total, there were 68 women

Table 1 :
Analysis of the clinical-pathological characteristics and survival according to gender among patients with oral squamous cell carcinomas.
Variables are expressed in absolute (N) and relative (%) values, Mean (standard deviation) or Median (minimum-maximum), as appropriated; Age is expressed in years; T: T Staging; N: N Staging; WD: well differentiated; MD: moderately differentiated; PD: poorly differentiated; Size and Depth of invasion are expressed in centimeters; p: significance level; * authors chose not to include other histological variants in statistical analysis, avoiding false-negative results attributable to low representativeness.