Role of CD133 & Microsatellite Status in Evaluation of Rectosigmoid Cancer Young Adults Received Neoadjuvant Treatment

Microsatellite instability is more common in colorectal cancer ( CRC) young patient which is associated with good prognosis and is considered as a predictor for good response to preoperative chemoradiotherapy. Counting of ( cluster of differentiation) CD 133 +ve cells ,as a marker for enrichment with colorectal cancer stem cells ,is considered as a prognostic marker for poor survival and predictor for radio-resistance. Correlation between microsatellite status ( MS) and CD133 count has not yet studied especially in young patients with rectosigmoid cancer. So the investigators hypothesize that there is correlation between microsatellite status, CD133+ve cells count , occurrence of CRC in young patients and resistance to standard treatment regimen. Improvement of response to treatment and choice of the best regime to avoid non beneficial treatment modality are the goal of this study.