 The age incidence of colorectal cancer is above fifty years old world wide .But, when comparing the incidence and clinicopathological features of colorectal cancer in western countries and countries with constrained resources as Egypt , there is significant lower median age of incidence. In Egypt reports showed that CRC was detected in 11-15 of patients who underwent colonoscopy and diagnosed in 29-31 of patients aged 40 years or younger . Similar data come from other highly populated resource-constrained countries in Asia . This early onset rectal cancer is mainly poorly differentiated, advanced at prognosis, sporadic with no familial predisposition.Young patients with microsatellite high MSI-h proximal cancer colon are with good prognosis but there is lacking data about the prognostic and predictive role of these genes in young patients with irradiated rectal cancer. As those young aged patients show worse outcome in term of progression free survival and higher rates of metastatic events , we hypothesize that colorectal cancer stem cells CR-CSC may have a role in this dismal outcome.CD133 is one of the best-characterized markers of CR-CSCs, many studies have demonstrated that CD133 expression was correlated with survival, recurrence, metastasis and chemotherapy resistance in colorectal cancer. 