Oliver, Jaime A.Gómez-Millán, JaimeMedina, Jose A.Cabeza, LauraPerazzoli, GloriaJimenez-Luna, CristinaDoello, KevinOrtiz, Raúl2025-01-072025-01-072019-06-14https://hdl.handle.net/10668/26485To analyze the clinical relevance of O6-methylguanine-DNA methyltransferase in rectal adenocarcinoma treated with chemoradiotherapy followed by surgery. Tissue samples from 29 rectal adenocarcinoma patients were obtained after chemoradiotherapy. O6-methylguanine-DNA methyltransferase promoter methylation status was established by methylation-specific polymerase chain reaction. O6-methylguanine-DNA methyltransferase protein levels were determined by immunohistochemistry. Clinicopathologic variables, including treatment regression grade, recurrence, lymph node invasion, and stage and differentiation grade of the tumor, were determined. The O6-methylguanine-DNA methyltransferase gene promoter was methylated in 81.5% of samples. Most patients (88.9%) showed low O6-methylguanine-DNA methyltransferase protein expression. O6-methylguanine-DNA methyltransferase methylation status was not correlated with any of the clinicopathological variables determined in rectal adenocarcinomas selected for chemoradiotherapy. O6-methylguanine-DNA methyltransferase methylation status is not correlated with clinicopathologic variables examined in rectal adenocarcinoma selected for chemoradiotherapy, although its role as a biomarker awaits further investigation.enAttribution-NonCommercial-NoDerivatives 4.0 Internationalhttp://creativecommons.org/licenses/by-nc-nd/4.0/ChemoradiotherapyO6-methylguanine-DNA methyltransferaserectal adenocarcinomaAdultAgedAged, 80 and overChemoradiotherapyFemaleHumansImmunohistochemistryMaleMethylationMiddle AgedO(6)-Methylguanine-DNA MethyltransferasePolymerase Chain ReactionProspective StudiesRectal NeoplasmsRecurrenceresearch article31199091open access10.4274/balkanmedj.galenos.2019.2018.12.932146-3131PMC6711248https://doi.org/10.4274/balkanmedj.galenos.2019.2018.12.93https://pmc.ncbi.nlm.nih.gov/articles/PMC6711248/pdf