Study Of The Correlation Between Tumor Stem Cell Surface Marker ALDH1and The Molecular Subtypes Of Breast Cancer

ObjectiveTo study the expression of tumor stem cell surface marker ALDH1positive phenotype in breast cancer; to investigate the relationship of the ALDH1positive phenotype and molecular subtypes of breast cancer as well as their relationship with the clinical and pathological features.MethodsFirst, according to the status of immunological markers including ER, PR and HER-2, breast cancers were divided into four molecular subtypes including Luminal A subtype, Luminal B subtype, Her-2overexpression subtype and Basal-like subtype.20cases of each subtype and20tumor adjacent normal breast tissues as well as20benign breast tumor tissues were retrieved from the department of pathology in Central South University Xiangya Second Hospital. Then, immunohistochemistry (IHC) was used to detect the expression of ALDH1in breast cancer group, tumor adjacent normal breast tissue group and benign breast tumor group.Results1. The ALDH1was negative expression in20tumor adjacent normal breast tissue group and20benign breast tumor group, While of the80invasive ductal carcinoma, ALDH1positive expression and negative expression was present in17(21.25%)、63(78.75%) cases, respectively, which was significantly different from the other two groups (P<0.05).2. The positive expression rate of ALDH1was10%(2/20) in Luminal A subtype,5%(1/20) in Luminal B subtype,30%(6/20) in Her-2overexpression subtype and40%(8/20) in Basal-like subtype, which showed the ALDH1positive expression in the molecular subtypes of breast cancer was significantly different (P<0.05), and ALDH1positive phenotype was highly expressed in Basal-like subtype and Her-2overexpression subtype and low present in Luminal subtype, but pairwise comparisons showed no significant difference between these groups, except Basal-like and Luminal (P<0.007, a=0.007).3. Basal-like subtype and Her-2overexpression subtype as well as ALDH1positive expression were related with ER negative and PR negative.The positive expression of ALDH1had no significant relation with clinical and pathological features including age, tumor size, clinical stage, lymph node metastasis, CK5/6, Top Ⅱ, Ki-67, but was significantly related to ER negative and PR negative (P<0.01).Conclusions1. Tumor stem cell surface marker ALDH1positive phenotype only accounted for a small part of breast cancer, which suggested that ALDH1may be beneficial to diagnose breast cancer and monitor its recurrence. The highly positive expression of ALDH1may be certain related to the recurrence, metastases and poor prognosis of breast cancer.2. ALDH1positive phenotype was highly expressed in Basal-like subtype and Her-2overexpression subtype, which explained the characteristics including worse prognosis, easier to recurrence and metastasis of the two types.