RESUMEN
Objective:To explore the clinical features and prognosis of simultaneous double primary and single primary colorectal cancer patients.Methods:A retrospective case series study was conducted. The clinical data of 45 patients with simultaneous double primary colorectal cancer, 53 patients with single primary colon cancer and 59 patients with single primary rectal cancer in Shanxi Province Cancer Hospital from January 2015 to January 2018 were retrospectively analyzed, including gender, age, drinking history, smoking history, body mass index (BMI), carcinoembryonic antigen (CEA), carbohydrate antigen 199 (CA199), hemoglobin, albumin, TNM stage. The clinicopathological characteristics of the three groups were compared. Survival analysis was performed using the Kaplan-Meier method to compare the overall survival of the three groups.Results:The age of simultaneous double primary colorectal cancer patients was (63±11) years old, including 28 males and 17 females; the age of single primary colon cancer patients was (61±12) years old, including 30 males and 23 females; the age of single primary rectal cancer patients was (60±11) years old, including 30 males and 29 females. There was a significant difference in BMI between patients with double primary cancer and single primary colon cancer ( P = 0.041), but there were no significant differences in gender, age, drinking history, smoking history, CEA, CA199, hemoglobin, albumin and TNM stage (all P > 0.05). There were significant differences in BMI, CEA and CA199 between patients with double primary cancer and single primary rectal cancer (all P < 0.05), but there were no significant differences in gender, age, drinking history, smoking history, hemoglobin, albumin and TNM stage (all P > 0.05). The 1-, 3- and 5-year overall survival rates of the double primary cancer patients were 95.56%, 77.78% and 62.22%, the single primary colon cancer patients were 94.34%, 81.13% and 69.81%, and the single primary rectal cancer patients were 100.00%, 88.14% and 72.88%, respectively. There was no significant difference in OS among patients with double primary cancer, single primary rectal cancer and single primary rectal cancer (both P > 0.05). Conclusions:Abnormally elevated BMI may be associated with the risk of developing simultaneous double primary colorectal cancer. Detection of CEA and CA199 is helpful in monitoring rectal cancer patients for the combination of other primary tumors. The prognosis of patients with single primary colon or rectal cancer is comparable to that of patients with simultaneous double primary colorectal cancer.