Independent prognostic value of the basal‐like phenotype of breast cancer and associations with EGFR and candidate stem cell marker BMI‐1

Abstract

Basal-like features and lymph node status were strong and independent prognostic factors in this population-based series of breast cancer. Neither EGFR nor BMI-1 had significant prognostic impact, whereas EZH2 expression was associated with decreased survival. BMI-1 was inversely related to basal-like factors, and a stem cell phenotype of the basal-like subgroup could not be verified by this marker.

Distinctive expression of the polycomb group proteins Bmi1 polycomb ring finger oncogene and enhancer of zeste homolog 2 in nonsmall cell lung cancers and their clinical and clinicopathologic significance

“…For other types of cancer, some studies demonstrated that overexpression of Bmi1 was correlated with a poor prognosis [42][43][44] ; however, others reported that loss of Bmi1 expression was correlated with an aggressive phenotype, indicating a protective role of the Bmi1 protein. [45][46][47] Abundant expression of Bmi1 in normal bronchial epithelial cells in the current study and in a previous report 19 and low Bmi1 expression in the majority of tumor cells suggest that Bmi1 may have a protective role in NSCLC. The role of Bmi1 in lung cancer remains to be defined.…”

Expression of aldehyde dehydrogenase 1 (ALDH1) is associated with basal-like markers and features of aggressive tumours in African breast cancer

“…This is in line with our recent studies of breast cancer and other tumours (Bachmann et al, 2008;Engelsen et al, 2008). The frequency of BMI-1 expression (25%) was lower than those found in other studies (43 -62%) (Kim et al, 2004;Arnes et al, 2008;Choi et al, 2009). Others have found different results, BMI-1 expression being associated with more aggressive tumours (Glinsky et al, 2005;Silva et al, 2007).…”

“…Still, BMI-1 has been linked to mammary carcinogenesis in some previous studies (Dimri et al, 2002;Datta et al, 2007). Although some find BMI-1 expression to be associated with a favourable prognosis (Kim et al, 2004;Arnes et al, 2008;Choi et al, 2009), others have reported the opposite (Glinsky et al, 2005;Silva et al, 2007).…”

“…We therefore merged luminal A and luminal B into the luminal subtype. Further, in accordance with our previous studies, we included P-cadherin staining in the definition of BLP (Nalwoga et al, 2007;Arnes et al, 2008). Using the Arnes et al (2008) criteria, we defined BLP profiles as follows: BLP1: concurrent ERÀ, HER2À and CK 5/6 þ ; BLP2: concurrent ERÀ, HER2À and P-cadherin þ ; BLP3: concurrent ERÀ, HER2À and EGFR þ ; BLP4: concurrent ERÀ, HER2À and CK 5/6 þ and/or EGFR þ ; BLP5: concurrent ERÀ, HER2À and positivity for one or more basal markers (CK 5/6, P-cadherin and EGFR).…”

“…A total of 183 -187 cases could be evaluated for the various markers. The oestrogen receptor (ER), progesterone receptor (PR), HER2, EGFR, Ki-67, p53, p63, cytokeratin (CK) 5/6, P-cadherin, c-kit and BMI-1 were evaluated as previously described (Engelsen et al, 2006;Stefansson et al, 2006;Arnes et al, 2008;Nalwoga et al, 2008). Regarding ALDH1, cytoplasmic staining was evaluated, whereas nuclear staining alone was considered nonspecific and was not included in the analysis.…”