# Comparative Analysis of COL9A1 Genotyping in Oral Squamous Cell Carcinoma Diagnosis: A Pilot Study
## 3 Results
### Tagged SNP of COL9A1 Gene Identification  
Our aim was to establish if there was a correlation between the presence of the C/T variant in the COL9A1 gene and both types of samples analysed, i.e., tumour tissue and blood samples. The results after genotyping the two types of samples were noted as positive if the presence of T was on one (C/T heterozygotes) or both (T/T homozygotes) of the alleles. The presence of the targeted variant was also correlated with gender and the incidence of risk factors. The T allele was identified in 87.5% (28 cases out of 32) of the tumor samples while the presence of the T allele in the blood samples was 65.5% (21 cases out of 32) (Table 27). The correlations of the encountered T alleles in the tissue and blood samples were statistically significant (chi-square test, \(p\) < 0.001) (Table 27). This aspect is a promising one, taking into consideration that the tissue samples belonged to OSCC diagnosed patients. These results highlight the potential of the presence of the COL9A1 gene mutation in blood samples as a promising biomarker for oral cancer screening. The visual relationship of the existence of the C/T gene in tissue and blood samples reveals that 12 out of 32 subjects presented the C/T gene variant in both tissue and blood samples, and five subjects out of 32 presented the C/T gene in the tissue sample only (Figure 27). \begin{table}
\begin{tabular}{c c c c c} \hline  & **Frequency** & **Percent** & **Valid Percent** & **Cumulative Percent** \\ \hline \multicolumn{4}{l}{**BLOOD SAMPLES**} \\
**VALID** & **NO** & 11 & 34.4 & 34.4 & 34.3 \\
**YES** & 21 & 65.6 & 65.6 & 100.0 \\
**TOTAL** & 32 & 100.0 & 100.0 & \\
**TUMOR TISSUE** & & & & \\
**VALID** & **NO** & 4 & 12.5 & 12.5 & 12.5 \\
**YES** & 28 & 87.5 & 87.5 & 100.0 \\
**TOTAL** & 32 & 100.0 & 100.0 & \\ \hline \end{tabular}
\end{table} 
Table 6: SNP frequency in tumour and blood samples. \begin{table}
\begin{tabular}{c c c c c c} \hline  & & & \multicolumn{3}{c}{**Tissue**} \\ \cline{3-5}  & & **C/C** & **C/T** & **T/T** & **Total** \\ \hline \multirow{4}{*}{Blood} & C/C & Count & 4 & 5 & 2 & 11 \\  & \% within blood & 36.4\% & 45.5\% & 18.2\% & 100.0\% \\ \cline{1-1}  & C/T & Count & 0 & 12 & 0 & 12 \\ \cline{1-1}  & \% within blood & 0.0\% & 100.0\% & 0.0\% & 100.0\% \\ \cline{1-1}  & T/T & \% within blood & 0.0\% & 0.0\% & 100.0\% & 100.0\% \\ \cline{1-1}  & \% within blood & 4 & 17 & 11 & 32 \\ \cline{1-1}  & Total & \% within blood & 12.5\% & 53.1\% & 34.4\% & 100.0\% \\ \hline \end{tabular}
\end{table} 
Table 7: Correlation between blood and tissue SNPs. The association of the incidence of the T allele within the blood samples of the two sexes was not statistically significant (\(p\) = 0.989, chi-square test) (Table 1). In addition, the presence of the T allele in the tissue samples between males and females showed no statistical significance (\(p\) = 0.773, [PERSON]'s corrected chi-square test) (Table 1). Among the included cases, 31.25% were histopathologically classified as T1, 53.13% as T2 and 15.62% as T3. The association between genetic alterations in the tissue samples and clinical staging was statistically significant (\(p\) = 0.046, chi-square test) (Figure 1). Further, the correlation of the identified genetic alterations of the COL9A1 in the blood samples and clinical staging was statistically significant (\(p\) = 0.0362, chi-square test) (Figure 1). The results concerning both tissue and blood samples showed that the C/T genetic mutation was predominantly associated with T2 clinical staging, suggesting its presence in the early clinical stages of OSCC with a potential influence on future early diagnosis. \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & & & **T Incidence in Blood** & **Total** \\ \hline \multirow{3}{*}{Sex} & & Yes & No & \\  & & Count & 13 & 7 & 20 \\ \cline{3-5}  & & \% within sex & 65.0\% & 35.0\% & 100.0\% \\ \cline{3-5}  & & Count & 8 & 4 & 12 \\ \cline{3-5}  & & \% within sex & 66.7\% & 33.3\% & 100.0\% \\ \hline \hline \end{tabular}
\end{table}