Objective: To investigate the differences in the amount of cancer stem cells in different breast cancer subtypes.
Methods: The specimens of breast cancer tissues were divided into five groups: group A (luminal A type)， B (luminal B type)， C (HER2+ type)， D (basal-like type) and E (normal-like) according to their molecular subtypes. The cancer stem cell spheres in each group were measured through colony formation method， and then the relations of the amount of cancer stem cells with the subtypes of breast cancer were analyzed.
Results:  The numbers of cancer stem cell spheres in group A and B were (1.1±0.2)/1 000 cells and (1.3±0.1)/1 000 cells， respectively， and this had no significant difference (P＞0.05). The number of cancer stem cell spheres in group C was (8.6±1.0)/1 000 cells， which was significantly higher than that in group A and B (both P＜0.05). The numbers of cancer stem cell spheres in group D and E were (22.4±1.2)/1 000 cells and (17.7±2.0)/1 000 cells， respectively， and this was statistically similar (P＞0.05) but either was significantly higher than that in the other three groups (all P＜0.05).
Conclusions: Breast cancer tissues of different molecular subtypes contain varying amounts of cancer stem cells， and this may have certain significance for predicting the prognosis of breast cancer.