The Expression Of ALDH1A1 In Colorectal Cancer And Its Prognostic Value

ObjectiveColorectal cancer(CRC)is a serious aggressive malignant tumor.Aldehyde dehydrogenase 1A1(ALDH1A1)has been shown to be a cancer stem cell marker for CRC.ALDH1A1 shows elevated levels in a variety of cancer types including CRC,and has been suggested as a potential biomarker for CRC.Here,we used tissue microarrays(TMAs)to investigate the expression of ALDH1A1 in a large cohort of CRC patients,measuring ALDH1 A levels in CRC tumor tissues and non-tumor adjacent tissues(NATs)by immunohistochemistry to further explore its clinical significance.We aim to evaluate the expression and prognostic value of ALDH1A1 in CRC.MethodsWe investigated the expression of ALDH1A1 by IHC staining of CRC tissue microarrays(TMAs)including 424 CRC tissues and 196 matched NATs.We analyzed the correlations between ALDH1A1 expression and clinicopathological characteristics to further explore its clinical significance.ResultsImmunohistochemistry(IHC)showed that the ALDH1A1 expression was significantly increased in CRC tissues compared with non-tumor adjacent tissues(NATs).The comparison of the clinicopathologic variables of patients with CRC and their ALDH1A1 expression revealed that high ALDH1A1 protein expression significantly associated with increased tumor spread to more distant or numerous regional lymph nodes(P = 0.002).Thepositive expression rates were 64.28 %(171/266)in N0 cases,75.49 %(77/102)in N1 cases and 82.14 %(46/56)in N2 cases.We used the Kaplan–Meier analysis with the log-rank test.This indicated that patients with high expression of ALDH1A1 had shorter overall survival(P < 0.001).Kaplan–Meier survival curves of patients stratified according to lymph node metastasis(N status)showed that high ALDH1A1 expression led a poor prognosis in patients with no lymph node metastasis(N0),however,there was no significant correlation between ALDH1A1 expression and prognosis for patients presenting with lymph node metastasis(N1-2).Univariate and multivariate analyses showed that ALDH1A1 expression is an independently prognostic marker for CRC(P <0.001).ConclusionsOur results indicate that ALDH1A1 is a biomarker for predicting lymph node metastasis and prognosis of CRC.