With respect to tumor differentiation, CEA and VEGF levels were near the cutoff levels in well-differentiated tumors, and much higher in moderately to poorly differentiated tumors, however, we were unable to include this in our study due to very limited number of patients with well-differentiated tumors (2 of 30) compared to moderate-poorly differentiated tumors (28 of 30), thereby preventing statistical comparison. Here, VEGFA is linked to neoplasm.