Julia Y. S. Tsang

Expression of mammaglobin and gross cystic disease fluid protein-15 in breast carcinomas ☆

Immunohistochemical analysis of gross cystic disease fluid protein-15 (GCDFP-15) and mammaglobin (MGB) is frequently used in routine practice for assessment of metastases or regional recurrences of breast origin. Breast cancer is highly heterogeneous. Expression of these 2 markers in various breast cancer subtypes has not been well studied. In addition, the usefulness of these two markers in combination in detecting breast origin has not been explored. In this study, a large cohort of breast cancers was evaluated for GCDFP-15 and MGB expression, both individually and combined. Their expression was correlated with cancer subtypes, other biomarkers and clinicopathologic parameters. A higher sensitivity for MGB (42.3%) than GCDFP-15 (31.6%) in detecting cancers of breast origin was observed. Combining both increased the sensitivity further, both for primary tumor (53.0%) and for nodal metastases (69.0%). GCDFP-15 was associated significantly with a breast cancer profile of good prognosis tumors, including lower grade (P < .001), pN (P = .029) and Ki-67 (P < .001) as well as negative basal markers expression (P = .043, .009, and .049 for c-Kit, CK5/6 and epidermal growth factor receptor, respectively) and, thus, may not be sensitive for detection of poor prognosis tumors. MGB has the highest expression in HER2-overexpressing cancers (56.6%), and may be a potentially useful marker for this subtype. Nonetheless, both markers showed low expression in the basal like (BLBC) subtype (11.9% and 21.4% for GCDFP-15 and MGB respectively), therefore, the detection of BLBC remains problematic. Negative results need to be interpreted with caution, and correlation with other clinical findings may be required to exclude the possibility of metastatic BLBC.

Cancer stem cell markers are associated with adverse biomarker profiles and molecular subtypes of breast cancer

Cumulative evidence has demonstrated the presence of cancer stem cells (CSC) in breast cancer and its putative role in cancer progression. Nonetheless, the clinical significance of CSC in breast cancer remains elusive. The underlying reasons could be due to the heterogeneity of breast cancer subtypes as well as different markers used to define breast CSC. In this study, three widely used markers (aldehyde dehydrogenase (ALDH)1+ and CD24−CD44+) were used to define two populations of CSC in a large cohort of breast cancers. The expressions of these markers were correlated with different clinicopathological features and the molecular subtypes. ALDH1+ breast cancers were associated with basal-like and HER2-overexpressing subtypes and the characteristics histologic features were related to these two subtypes. On the other hand, CD24−CD44+ breast cancers were associated positively with the presence of extensive in situ component, the absence of lymph node involvement, and basal markers, but negatively with HER2. CD24−CD44+ breast cancers were also positively associated with luminal B cancers. As the expression of CSC markers varied among different molecular subtypes and different clinicopathological features, it appeared that each CSC population could have distinct clinical values in different subgroups of breast cancers. For improved prognostication with CSC, combining the analysis of CSC markers would be required. Within the luminal cancers, CSC appeared to identify cancers with poor outcome. The presence of CSC populations was associated with ER−PR+ cancers and tumors expressing basal markers. Basal marker expression can complement with CSC for improved indicator for poor prognosis in luminal breast cancers. For the first time, the possible contribution of CSC to these aggressive luminal cancers was demonstrated. The association of basal features and CSC in luminal cancers also raised the possibility that luminal cancer cells may acquire basal phenotype and CSC properties together during their progression.

αB-crystallin is a useful marker for triple negative and basal breast cancers

Tsang J Y S, Lai M W H, Wong K H Y, Chan S‐K, Lam C C F, Tsang A K H, Yu A M C, Tan P‐H & Tse G M 
(2012) Histopathology 61, 378–386

Increased SOX2 expression in less differentiated breast carcinomas and their lymph node metastases

SOX2 is a key regulatory gene in embryonic stem cells. Although it has been implicated in cancer progression, its role in breast carcinoma is poorly understood.

Biopsy sampling of breast lesions: comparison of core needle- and vacuum-assisted breast biopsies

Needle biopsy is now the initial investigation of choice for the pre-operative diagnosis of breast lesions. This includes core needle biopsy (CNB) and vacuum-assisted biopsy (VAB) with or without radiologic assistance. The performance indices of both of these biopsy techniques were evaluated. In a large cohort of patients with breast lesions including 464 cases (285 CNB and 179 VAB), with confirmed outcomes, the diagnostic accuracy was compared using parameters including quantitation of the sampling based on the total number of cores taken, cores containing breast parenchyma, and cores with lesion; and non-epithelial changes including necrosis and calcification. CNB showed a 99% PPV, 94% NPV, 96% sensitivity, and 99% specificity, whereas VAB demonstrated a 100% PPV, 100% NPV, 100% sensitivity, and 100% specificity. The correct diagnosis in CNB was proportional to the number of cores extracted, whereas accuracy of VAB was independent of the total number of cores taken. There was a positive correlation between the presence of calcification and malignancy in CNB, but not detected under VAB. CNB and VAB were equally efficient in palpable lesions, in detecting necrosis, and calcification. Large calcification was found to be associated with malignancy in both CNB and VAB. In non-palpable lesions, VAB was more effective in the detection of calcification. The diagnostic accuracy of VAB appeared to be independent of number of cores sampled, whereas CNB required a minimum of 3–4 cores to achieve high diagnostic accuracy.

TTF-1 expression in breast carcinoma: an unusual but real phenomenon.

To evaluate thyroid transcription factor‐1 (TTF‐1) expression in a large cohort of invasive breast carcinomas (IBCs) using two commercially available monoclonal antibody clones (8G7G3/1 and SPT24).

Doublecortin-like kinase 1 expression associates with breast cancer with neuroendocrine differentiation

Doublecortin-like kinase 1 (DCLK1), a microtubule associated kinase, has recently been proposed to be a putative marker for stemness and adverse prognosis in gastrointestinal cancers. However, it is not clear whether the protein also plays similar roles in breast cancer. Here, the expression of DCLK1 was analyzed in a large cohort of invasive breast cancers (IBC) by immunohistochemistry. DCKL1 was associated with favorable clinico-pathologic features, namely lower histologic grade, absence of lymphovascular invasion, fibrotic focus, necrosis and lower pN stage (p≤0.045). Additionally, independent significant correlations were found with estrogen receptor and neuroendocrine markers (p ≤0.019), implicating its relationship with IBC with neuroendocrine differentiation (IBC-NED). In the current cohort, IBC-NED showed worse outcome than luminal cancers without NED (hazard ratio=1.756, p=0.041). Interestingly, within the IBC-NED group, DCLK1 was found to be a good prognostic factor (hazard ratio =0.288, p=0.011). These findings were in contrast to those in gastrointestinal cancers, suggesting different functional roles of DCLK1 in different types of cancers. In clinical practice, NED is not routinely assessed; thus IBC-NED are not well studied. Its poor outcome and significant heterogeneity warrants more attention. DCLK1 expression could aid in the prognostication and management of this special cancer subtype.

FGFR1 is an adverse outcome indicator for luminal A breast cancers

Fibroblast growth factor receptor 1 (FGFR1) has been suggested to be the candidate gene for 8p11–12 amplification in breast cancer and its therapeutic/prognostic value is explored. Most previous studies focused on FGFR1 gene amplification, which may not necessarily lead to protein expression. Therefore, analysis of protein level may have more clinical relevance. We evaluated FGFR1 expression in a large cohort of breast cancer by immunohistochemistry, correlated with the tumor clinic-pathologic features, biomarkers expression, and patients survival. FGFR1 expression was associated mainly with luminal cancers, particularly luminal B subtype (23.5%; p < 0.001), and it also showed adverse prognostic impact on luminal A cancers. FGFR1 expression was associated with higher pN (p = 0.023), pT (p = 0.003) stages, lymphovascular invasion (p = 0.010), p-cadherin (p = 0.028), synaptophysin (p = 0.009) and SOX2 expression (p = 0.034) in luminal A cancers. FGFR1 expressing luminal A cancers showed a similar outcome as luminal B cancers. Multivariate Cox regression analysis demonstrated FGFR1 positive luminal A cancers to be an independently poor prognosticator for disease free survival in luminal cancers (hazard ratio = 3.341, p = 0.008). Thus FGFR1 could be useful in identifying the aggressive cases amongst heterogeneous luminal A cancers. Given the relevance of FGFR pathway in treatment resistance in luminal cancers, FGFR1 could be an important tumor biomarker and adverse prognostic factor potentially exploitable in the clinical management of luminal cancers.

Columnar cell-like changes in the male breast

Aims Columnar cell lesions are known as a link between normal breast and low grade neoplastic lesions in female, but have not been established in the male breast. This study evaluated the presence of ducts showing columnar cell-like features in the male breast. Methods Seventy-one consecutive surgical resections from men (6 invasive breast carcinoma of grade 3, 1 atypical ductal hyperplasia and 64 other lesions) were reviewed to identify foci of dilated ducts with columnar epithelial cells, and their morphological features including apical snouts, intraluminal secretions and calcifications were assessed. The expression of CK5/6 and estrogen receptor (ER) was evaluated immunohistochemically. Clinicopathological features including patients’ age, histological diagnosis and gynaecomastoid hyperplasia were documented. Results Ducts showing columnar cell-like features were identified in 39 cases, morphologically as distended ducts with round or undulating outline. There was an outer layer of myoepithelial cells and an inner layer of columnar luminal cells showing apical snouts, but without intraluminal secretions or calcifications. Immunohistochemically, these columnar epithelial cells were negative for CK5/6 in 38/39 cases and all were ER heterogeneously positive. These changes were associated with older age, but their incidence did not differ whether they were associated with invasive breast carcinoma, atypical ductal hyperplasia and other lesions. Conclusions In the male breast, there is an entity sharing morphological features and immunohistochemical profile of columnar cell lesions.

Nerve growth factor receptor (NGFR): a potential marker for specific molecular subtypes of breast cancer

Aims Nerve growth factor receptor (NGFR) is a transmembrane receptor for the neurotrophin family. It acts either as tumour suppressor or oncogene depending on cellular context. Its role in breast cancers remained conflicting, possibly due to the heterogeneity of breast cancer subtypes. Methods In this study, we have analysed NGFR expression in 602 cases of breast cancers by immunohistochemistry. Its expression was correlated with biomarker expression and different breast cancer subtypes. Results NGFR expression was found to be positively correlated with basal markers, including Ki67, Cytokeratin (CK5/6), CK14, p63, c-kit and Epidermal growth factor receptor (EGFR) , but negatively with hormonal receptors. Among different molecular subtypes, it was negatively associated with luminal A, but positively with luminal B, and basal-like breast cancer BLBC subtypes. When comparing NGFR with other basal markers in BLBC, though less sensitive, its specificity was comparable to or better than other basal markers. For luminal B cancers, NGFR showed a high specificity which was also comparable to or better than the defining markers (estrogen receptor (ER), progesterone receptor (PR), Human epidermal growth receptor 2 (HER2) and Ki-67) for the subtype. Conclusions Overall, these findings suggested that NGFR expression could be indicative for the BLBCs or luminal B subtypes. It may represent a potential adjunct marker for these two subtypes.