Colorectal cancer (CRC) is the third most common cancer in the world. Tumors are most commonly located in the rectosigmoid region. There are many factors in the etiology such as age, geographical features, family history, obesity, diet, and history of malignancy. In the present study, we aimed to determine the effect of blood group characteristics, which play a role in the etiology of stomach cancer, on the etiology of CRC.
We retrospectively reviewed the files of patients who were diagnosed with CRC and operated in our center or at other centers and were followed postoperatively at our centers. Age, gender, histologic TNM stage (tumor, lymph node involvement, and metastasis), tumor-bearing colon segment, ABO blood group, and Rh antigen were examined from the patients’ records.
There were 265 (54.5%) patients with lymph node involvement and 53 (10.9%) with liver metastasis. The most common tumor location was the rectum (n=203). When the blood group and Rh antigen subgroups were examined, blood group A was detected in 253 patients (52.1%), blood group B in 115 patients (23.7%), blood group O in 78 patients (16%), and blood group AB in 40 patients. The incidence of colon cancer was found to be significant in patients with A (+) blood group (p<0.001).
As in stomach cancer, our findings show that the A (+) blood group is a risk factor in colorectal cancers, which have multifactorial etiology. Further genetic studies are needed.
Keywords: Colorectal cancer, ABO blood group, Rh antigen