Yang L, et al. - Researchers used the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) data to compare incidence and survival of initial primary colorectal cancer (IPCRC) and second primary colorectal cancer (SPCRC) and describe risk factors for SPCRC and comparing different SPCRC traits, given IPCRC has an elevated risk of developing into SPCRC. They observed a 1.73 times higher likelihood to develop SPCRC among patients with IPCRC. SPCRC vs IPCRC had poorer survival, and the best survival outcome was seen in right-sided colon cancer (RCC), among those who had SPCRC. Black ethnicity, age range 70–79, and left-sided colon cancer (LCC) were found to be related to the greatest risk of SPCRC development. Relatively narrow characteristic differences were observed between second LCC and RCC.