• 2019-10
  • 2019-11
  • 2020-03
  • 2020-07
  • 2020-08
  • br Statistical analysis br Data


    2.2. Statistical analysis
    Data was subjected to normality testing using Shapiro-Wilk test and was found to be normally distributed. Hence parametric test (ANOVA) was used. P-values less than 0.05 (P < 0.05) were considered as indicative of significance. Significant differences between the groups were determined using one-way analysis of variance, LSD Post HOC, unpaired t test, and Pearson’s correlation.
    3. Results
    Salivary endothelin 1 levels in OL, SMF, and OSCC patients and in controls were measured using sandwich ELISA test. There were 43 males and 17 females in our study group. The demographic distribution of subjects within the study groups are mentioned in Table 1.
    All the cases included in the study had association with tobacco and alcohol consumption. Control group was free of any deleterious habit. Table 2 presents the clinical and histopatholog-ical data of cases.
    In our study the mean S.D: Salivary Endothelin-1 level in study groups was: 82.78 5.9 pg/ml in OSCC, 65.02 1.8 pg/mL in SMF, 57.76 4.1 pg/ml in Leukoplakia and 29.72 14.1 pg/mL in healthy controls. The mean Salivary Endothelin-1 levels among these four groups was compared using ANOVA and the difference was statistically significant (F = 113.69, P < 0.001). Therefore, by this analysis it can be inferred that there was a significantly higher SCH772984 of salivary ET-1 levels in OSCC followed by OSMF and OL groups respectively. (Table 3, Fig. 1). LSD Post hoc tests were carried out for all the pairs of groups (P < 0.001, adjusted using the Bonferroni correction) which showed a significant difference in salivary endothelin levels between OSCC and SMF (P < 0.001), OSCC and Leukoplakia (P < 0.001), OSCC and Controls (P < 0.001), SMF and Controls (P < 0.001) and Leukoplakia and Controls (P < 0.001). The difference in salivary endothelin levels between SMF and Leukoplakia (P = 0.016) was not statistically significant (Table 4). Correlation of salivary ET-1 levels with habit history was done among the study groups; using Point Biserial Correlation. Within Leukoplakia Group; ET-1 Level with Smokeless form of tobacco showed a positive correlation (rbi = 0.41, P = 0.12) (Table 5). Within SMF and OSCC group, analysis of ET-1 Levels with Smoked form of tobacco showed a negative correlation (rbi = 0.29, P = 0.29) and with male gender
    Group Total number (n) Age
    Please cite this article in press as: Ankita K, et al. Assessment of salivary endothelin-1 in patients with leukoplakia, submucous fibrosis, oral cancer and healthy individuals – a comparative study. J Stomatol Oral Maxillofac Surg (2019), j.jormas.2019.02.024
    Table 2
    Clinical and histopathological data of cases.
    Group Clinical stage/Type Number (%)
    OSCC AJCC TNM Staging
    Grade 1 r> Homogeneous
    Non-homogeneous 3(20)
    Proliferative verrucous leukoplakia 1(6) Group Histopathological grading Number (%) OSCC Well differentiated 6(40)
    Moderately differentiated 7(46)
    Poorly differentiated 2(13) SMF Very early 2(13)
    Moderately advanced 6(40)
    Advanced 1(6) OL Epithelial dysplasia (mild, moderate 13(86.6)
    and severe)
    Hyperkeratosis 2(13)
    showed a positive correlation (rbi = 0.36, P = 0.51) (Table 5).There was no statistically significant difference with the association of salivary ET-1 levels and gender in OSCC group (Table 5.5). Association of ET-1 levels with clinical and histopathological staging was done among the study groups. Within Leukoplakia group, using Spearman’s r correlation, salivary ET-1 level with histological staging (P = 0.41,
    Histological staging showed a negative correlation (P = 0.18, P = 0.52) whereas salivary ET-1 Levels with Clinical staging showed
    a positive correlation (P = 0.06, P = 0.82). Also, there was no statistical significant association between age and salivary ET-1 levels among OL and SMF patients (Table 6). Among OSCC group Correlation of ET-1 Level with Histological staging showed a positive correlation (P = 0.08, P = 0.78) and showed a negative correlation
    4. Discussion
    Oral cancer is a global health issue. Oral squamous cell carcinoma (OSCC) is one of the most common epithelial malignancies with significant morbidity and mortality. In spite of diagnostic and therapeutic advances over the decades, the disease still remains a challenge for medical professionals with the
    Table 3
    The mean S.D: salivary endothelin-1 level in study groups.
    five year survival rate being 30%–50%. Recent observations indicate that the clinical and histological appearance of oral mucosa may not truly depict the damage occurring at the genetic level. An understanding of the molecular mechanisms involved in OSCC is helpful in providing a more complete picture of the ways in which tumor arise and advance and a rationale for novel strategies of cancer detection. The oral cavity is particularly conducive to such strategies, given the ease with which saliva and exfoliated cells can be collected [11].Comprehensive analysis and identification of the salivary proteome may be necessary to understand fully the oral pathophysiology, on one hand, and the possibility of using salivary proteins and peptides as biomarkers of systemic disease, on the other. Previous literature states that expression of endothelins and their receptors is associated with high grade, aggressive colon, colorectal and oesophageal cancers as well as invasion and metastasis and thereby, plays a principle role as a potential biomarker.