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

Basal-like breast cancers (BLBCs), a breast cancer subtype with triple-negative status, pose significant problems in clinical management because of their aggressive behaviour. Recently, an association between αΒ-crystallin expression and BLBCs has been suggested, and we therefore investigated whether αΒ-crystallin could be a putative marker allowing BLBCs to be identified more accurately.

We evaluated the expression of αB-crystallin and other biomarkers in 395 cases of breast carcinoma by immunohistochemistry, analysed the correlation of their expression with different breast cancer subtypes, and compared their sensitivity as well as specificity in identifying BLBCs. αΒ-crystallin expression was found to be correlated positively with basal markers and histological subtypes associated with BLBCs. A significant positive correlation of αΒ-crystallin expression was also found with triple-negative breast cancers (TNBC) (C = 0.409, P < 0.001) and BLBCs (C = 0.393, P < 0.001). Comparing αΒ-crystallin with other basal markers, only αΒ-crystallin demonstrated both high sensitivity (48.6%) and specificity (93.8%) as a TNBC marker. All other markers showed either a lower sensitivity of <40% or a lower specificity of <90%. αΒ-crystallin also demonstrated a high specificity (92.9%) and an even higher sensitivity (56.5%) for BLBCs.

The findings indicated that αB-crystallin was a highly sensitive and specific marker for TNBCs and BLBCs.