MRI and correlation between TNM and CEA, CA19.9, AFP in rectal cancer Experience of a single academic surgical center

In our study we examined 75 patients treated for rectal cancer in the period between 01/01/2011 and 31/12/2014. Out of these 75 patients, we considered those 36 staged through MRI. We then compared the TNM stage obtained through MRI with the one emerged from histological examination. The correlation between the two TNM stages was assessed considering all patients staged through MRI and dividing the cases according to the submission or not to a neoadjuvant treatment. Finally, we analyzed serum levels of tumor markers CEA, CA 19.9 and AFP, relating them with the final disease stage. Data analysis showed a statistically significant correlation in the T stages, especially in the population not subjected to neoadjuvant treatment. Instead, for N, we found no statistically significant correlation. Similarly, none of the tumor markers presented a statistically significant correlation with disease stage. However, according to the positivity of tumor markers, we associated the following score: 0, (no positive marker)1 (only one marker positive) 2 (two markers positive) 3 (three markers positive). In presence of three markers positive, meaning the highest score, we found a statistically significant correlation with N + staging of the disease, obtained by postoperative pathologic examination. The conclusion is that MRI is certainly effective in T stage evaluation. Probably, for limph node involvement evaluation, more reliable parameters for establishing possible lymph node malignancy need to be found. The role of the tumor markers CEA, CA 19.9, AFP during preoperative evaluation of rectal tumors remains undefined. KEY WORDS: MRI, Rectal cancer, Tumor markes, Tumor regression, T stage.