“…Most of the studies evaluating IBM as prognostic factors studied Asian-based populations [ 9 , 14 , 16 , 18 , 19 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 ], where use of anti-cancer drugs, particularly trastuzumab, is inconsistently reported, inducing heterogeneity in survival expectations. This demographic variable could be associated with specific molecular and pharmacological features that can induce differences in toxicity and efficacy profiles.…”