In this work we show that the percentage of Ki-RAS mutations in codons
12 and 13 in rectal cancer are sensibly lower than in colon cancer, providing further
evidence that these two kinds of tumors should be considered two different entities.
Moreover, we show that the detection in regional lymph nodes of the same mutation of
primary tumor might represent an indicator of lymph nodes metastasis in rectal
carcinoma not detected in routine histologic examination
