LDHA is differential expressed in luminal A and luminal B breast cancer

Background Breast cancer (BrCa) is the most incident cancer in women worldwide, with more than 2 200 000 new cases and 600 000 deaths in 2020. Concerning BrCa molecular signature, tumors expressing estrogen receptor (luminal A and B) normally respond to hormonal therapy, but some cases develop resistance. We recently showed that LDHA expression is reduced upon treatment with [C16Pyr][Amp], a new proposed anti-cancer drug. LDHA has been implicated in Warburg effect regulation and has been associated with BrCa patients’ worse outcome. So, the mail goal of this study was to evaluate LDHA expression in BrCa tissues and correlate it with several clinical and pathological parameters. Methods A total of 40 BrCa tissue samples were selected to assess LDHA expression by immunohistochemistry. Percentage of positive tumor cells, intensity of immunostaining, and immunoexpression pattern were blinded evaluated. Correlations between clinicopathological parameters and LDHA expression were assessed using the Chi square test (P < 0.05 was indicated of the statistically significance). Results Higher LDHA expression intensity significantly is associated with luminal B molecular subtype (P = 0.003). Conversely, no association is found between LDHA expression and tumor stage or therapy resistance. Conclusions The intensity of LDHA immunoexpression is related with luminal molecular subtype B. Since LDHA is associated with the production of lactate, leading to a greater energy obtaining by cancer cells, these cells may have an increased capacity for proliferation. In fact, this subtype was previously reported to express high Ki67 levels, a proliferative marker.