• ALDH1;
  • breast cancer;
  • immunohistochemistry

Yoshioka T, Umekita Y, Ohi Y, Souda M, Sagara Y, Sagara Y, Sagara Y, Rai Y & Tanimoto A (2011) Histopathology58, 608–616 Aldehyde dehydrogenase 1 expression is a predictor of poor prognosis in node-positive breast cancers: a long-term follow-up study

Aims:  Aldehyde dehydrogenase 1 (ALDH1) has been identified as a reliable marker of breast cancer stem cells. The aim was to determine the prognostic significance of ALDH1 expression in a long-term follow-up study.

Methods and results:  Immunohistochemical analyses were performed on 257 invasive ductal carcinomas (IDCs), 109 matched lymph node metastases and 190 ductal carcinomas in situ (DCISs), using paraffin-embedded sections. ALDH1 expression was found in 26% of IDCs, and correlated with larger tumour size (P = 0.007), high histological grade (P < 0.001), HER2 overexpression (P < 0.001) and negative hormone receptor status (P < 0.001). ALDH1 expression was observed in 14% of DCISs but was not correlated with any clinicopathological parameter. The IDC patients were followed up for 7–190 months (median: 120 months), and groups with ALDH1 expression had shorter relapse-free survival (P = 0.0013) and overall survival (OS) (P = 0.0005) by log-rank test. By Cox’s multivariate analysis, it had a weak effect on OS (P = 0.047), and its most significant effect on OS was observed in node-positive groups (P = 0.013). No significant differences in OS stratified by ALDH1 expression status in lymph node metastases were noted.

Conclusions:  ALDH1 expression in primary cancer is an independent prognostic factor in node-positive breast cancer patients.