Aldehyde dehydrogenase 1 A1 (ALDH1) is a marker for normal stem cells (SCs) and tumour initiating cells in breast. Our recent study linked ALDH1 positivity in benign breast ductules in pre-menopausal women with hormonal and familial risk factors for cancer. It is unclear if this relationship has to do with SCs. Therefore this study investigated associations between putatively more specific SC marker combinations and cancer risk factors in these patient groups. Further, the importance of these markers was investigated for the stroma.
Triple immunohistological analyses using ALDH1, CD44 and CD24 were done on benign ductular and stromal tissue from randomly selected pre-menopausal patients with BRCA1 mutation (n=17), family history of breast cancer but no BRCA1/2 mutation (n=4), and no family history or BRCA1/2 or mutation (n=19).
The results confirmed associations between the ALDH1+ ductular immunophenotype in breast tissue and family history and low parity. This was significant for both ductular cells and stromal spindle-shaped cells. Corresponding associations were neither found for cells positive for the SC marker CD44, nor for the more stringent SC immunphenotype ALDH1+ CD44+ CD24–.
These results did not support the hypothesis that the association between ALDH1 and risk factors for breast cancer is related to stemness. Also, results indicated that ALDH1+ spindle-shaped stromal cells in breast stroma should to be examined further with regard to their potential role in oncogenesis.