Introduction Genomic mutations in TP53 gene in association with etiological risk factors have been associated with oral carcinogenesis. Herein, we screened for genomic variants of TP53 predisposing to oral cancers in Senegalese patients. Methodology 88 patients with confirmed diagnostic were recruited after informed consent. Blood samples were collected from each patient to perform DNA extraction, PCR amplification of all coding exons of TP53 followed by Sanger Sequencing of PCR products. Nucleotide sequences were analysed with Genalys software. 94 blood donors with no cancer diagnosis were also recruited as controls for association study between the most common variants identified in patients and predisposition to oral cancers. Results Sequence analysis showed that 52.27% of patients carry at least one mutation in TP53. Eleven genomic variants were identified, 7 variants already reported in databases and 4 new variants. The most recurrent variants in this study already reported as cancer-related variants were Pro72Arg (rs1042522; Arginine frequency estimated at 31.26%) and a 16 bp insertion in intron 3 (rs59758982; allelic frequency estimated at 26.25%). Haplotype analysis between these variants showed a strong linkage disequilibrium (D’ = 0.999, r2 = 0.153 and p-value < 0.05). However, association study did not find any significant association with susceptibility to oral cancer (p-value > 0.05). Conclusion Our study highlighted that despite the absence of association between the two most common cancer-related variants in Senegalese patients diagnosed with oral cancer, their strong LD suggested that they could be transmitted together in a common haplotype which may be implicated in oral carcinogenesis.

Oral cavity cancers are part of head and neck cancers. They have become frequent in the world in general and Senegal in particular. This study evaluates microsatellite instability tumors in oral cavity cancers in Senegal. Forty cancerous tissues, 20 healthy tissues, and 12 blood tissues were included in this study. These tissues were collected from each patient during the biopsy after obtaining consent. DNA extraction, Polymerase Chain Reaction (PCR) and sequencing were carried out to obtain sequences. Mutation surveyor, Bioedit and Dnasp software were used to perform our analyses. High instability was found in 57.5% of patients with cancer. Moreover, 90% of the patients had the same motif on healthy and cancerous tissue. Furthermore, 26.12%, 20.72%, and 11.71% polymorphic sites were found in cancerous, healthy and blood tissue respectively. Thus, a similarity between cancerous and healthy tissues seems to exist. This implies that instability of the Bat 26 microsatellite could occur early in the occurrence of oral cavity cancers.