Let-7 is a tumour suppressor miRNA which acts by down-regulating several oncogenes including KRAS.
READ FULL ARTICLE
From Annals of Oncology
Possible Link Between rs61764370, Prognosis in Colorectal Cancer
the Cancer Therapy Advisor take:
The single nucleotide polymorphism (rs61764370, T>G base substitution) in the let-7 (a tumor suppressor miRNA) complementary site 6 (LCS-6) of KRAS mRNA may be a response biomarker to neoadjuvant therapy, according to an article published online in the journal Annals of Oncology.
The study included 164 patients with colorectal cancer, 155 (94.5%) of which were analyzed successfully. Of the 155 patients, 123 (79.4%) had the LCS-6 TT genotype and 32 (20.6%) had the LCS-6 TG genotype.
Patients who were carriers of the G allele had a significantly greater rate of complete response after being administered neoadjuvant therapy (28.1% vs. 10.6%; P=0.020) and a trend for better rates of 5-year progression-free survival (PFS; 77.4% vs. 64.5%; HR 0.56; P=0.152) and overall survival (OS; 80.3% vs. 71.9%: HR 0.59; P=0.234).
Results showed the complete response and survival outcomes were found to be independent of the use of cetuximab, which led to the conclusion that rs61764370 does not appear to predict benefit.
Furthermore, it was observed that patients with the LCS-6 TT genotype appeared to have a stronger correlation to the negative prognostic effects associated with the KRAS mutation (HR PFS 1.70, P=0.078; HR OS 1.79, P=0.082) compared to patients with the LCS-6 TG genotype (HR PFS 1.33, P=0.713; HR OS 1.01, P=0.995).
