I would like to congratulate Kawashima and colleagues for their study in which they evaluated whether intravoxel incoherent motion and dynamic contrast-enhanced magnetic resonance imaging can differentiate luminal-B (LBBC) from luminal-A breast cancer among 134 patients. They reported that a higher signal enhancement ratio value and a lower pure diffusion coefficient (D) value were predictive of LBBC. Interestingly, the diameters of LBBC tumors (median = 22 mm; range = 11–75 mm) were significantly greater than those of luminal-A breast cancer tumors (median = 18 mm; range = 10–45 mm; P = 0.016). Signal enhancement ratio values are expected to be higher in tumors with greater tumors. Therefore, the results obtained from the current study might be confounded since patients with LBBC had a greater tumor size at the diagnosis.
Reference
- 1. Kawashima H., Miyati T., Ohno N., et. al.: Differentiation between luminal-A and luminal-B breast cancer using intravoxel incoherent motion and dynamic contrast-enhanced magnetic resonance imaging. Acad Radiol 2017; S1076-6332(17)30307-0 [pii]; Epub ahead of print