MRI In rectal cancer: Correlations between MRI features and molecular markers Ki-67, HIF-1α, and VEGF.

PurposeTo investigate whether the apparent diffusion coefficient (ADC) values acquired from diffusion-weighted magnetic resonance imaging (DW-MRI) are correlated with molecular markers Ki-67, hypoxia-inducible factor 1 (HIF-1), and vascular endothelial growth factor (VEGF) in rectal cancer (RC). Materials and MethodsNinety-one patients (64 males and 27 females) diagnosed with rectal cancer underwent 3.0T DW-MRI before any anticancer treatment. DW-MRI was performed using the single-shot echo-planar imaging technique (b=0 and b=800 s/mm(2)). The patients underwent surgery within 1 week after MRI. Ki-67, HIF-1, and VEGF expression were assessed by immunohistochemistry at both the resected margins and the center of the tumor. ResultsWe noted that ADC values correlated positively with histology differentiations (r=0.336, P=0.001) and negatively with carcinoembryonic antigen level (r=-0.217, P=0.039) in RC. Both the value and the level of Ki-67 expression were correlated inversely with the ADC values (r=-0.475, P<0.001 and r=-0.555, P<0.001). There was a weak negative correlation between HIF-1 expression and the ADC values (r=-0.304, P=0.003). VEGF expression was correlated inversely with the ADC values of the RCs (r=-0.290, P=0.005). However, no significant correlation was observed between VEGF expression and the ADC values in pT4 RCs (r=-0.166, P=0.255). ConclusionOur results suggest that the ADC values on DW-MRI may be used as a measurement of cell proliferation and hypoxia in RC. J. Magn. Reson. Imaging 2016;44:594-600.