Introduction: Advances in molecular biology have opened the door to a wide range of research material through the usage of genetic testing on certain variables within the human genome known as single-nucleotide polymorphisms (SNPs).The purpose of this article is to present a review on the influence variants within SNPs have on the outcome of laryngeal cancer when associated with different variables, such as external toxins or survival rate. Amongst these toxins, the most frequent and most studied have been alcohol and tobacco consumption, with a proven increased rate of overall cancer risk within the aero-digestive tract.
Materials and methods: The review was realized utilizing available studies on the subject of genetic polymorphisms analysis of deoxyribonucleic acid (DNA) samples using polymerase chain reaction (PCR) assays and laryngeal cancer published in the PubMed database.
Results: Statistical analysis of 262 polymorphisms shows a predominantly positive association between two genetic variants of the human genome (mutant homozygote and heterozygote) and cancer risk with significant influence on patient outcome and survival. Genotype combinations were divided into two categories depending on the individual 'at risk' and 'protective' allele within the loci of each inherited gene block. Amongst the genes involved with aero-digestive cancers, the most studied were those belonging to the xenobiotic metabolism, nucleotide excision repair (NER) and DNA repair pathways. The presence of toxins has a distinct cumulative effect within the genotype-phenotype relationship, which further influences the presence of malignancy depending on the adaptability of each individual genome.
Conclusions: Laryngeal cancer evolution is linked to inherited risk factors found within the genetic code. Most studied were the genes belonging to NER pathways, DNA repair and xenobiotic metabolism, which all favored mutant homozygote and heterozygote variants, as high risk factors. Only five articles focused on overall survival rates with insufficient results to undisputedly predict the risk variants. The consumption of external toxins has a positive effect on the overall cancer risk in consumers. Most articles affirmed further evaluation or replication was needed in a larger scale population to conclusively validate their results.