Evaluation of magnetic resonance imaging in staging of rectal cancer and its relationship with P16 expression.

OBJECTIVE: To explore the use of magnetic resonance imaging (MRI) in the staging of rectal cancer and its relationship with p16 expression. PATIENTS AND METHODS: A total of 75 patients with rectal cancer treated in Oncology Department of our hospital from March 2013 to March 2017 were randomly included in this study. The entire pelvis was scanned by MRI, and clinicopathological staging was diagnosed. Subsequently, all patients underwent total mesorectal excision (TME). Histopathological gold standard [hematoxylin-eosin (HE) staining] was used to determine the stage. Immunohistochemistry (IHC) was adopted to detect the expression of p16 in cancer tissues and cancer-adjacent tissues. Compared with the results of the pathological examination, the accuracy of MRI diagnosis was analyzed. The relationship between p16 expression and MRI diagnostic materials was analyzed. RESULTS: Compared with the results of the pathological examination, the total accuracy of MRI in the evaluation of T staging was 76.0% (57/75), and the excessive staging rate and insufficient staging rate were 8.0% (6/75) and 16.0% (12/75), respectively in the assessment of tumor T staging. IHC indicated that the positive expression rate of p16 in the tumor tissues was significantly lower than that in the tumor-adjacent tissues [34.67% (26/75) vs. 85.33% (64/75), p<0.05]. The chi-square test showed that the expression of p16 in the tumors was notably correlated with T staging, N staging, and myometrial invasion diagnosed with MRI. CONCLUSIONS: P16 is significantly deficient in the rectal cancer tissues. MRI examination and identification are helpful for clinical diagnosis of rectal cancer staging. The combination of the two items may be helpful for the diagnosis of clinical rectal cancer staging and the establishment of reasonable treatment regimens.