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

Purpose: To 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 1α (HIF-1α), and vascular endothelial growth factor (VEGF) in rectal cancer (RC).

Materials And Methods: Ninety-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-1α, and VEGF expression were assessed by immunohistochemistry at both the resected margins and the center of the tumor.

Results: We 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-1α 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).

Conclusion: Our 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.