To investigate the clinicopathologic characteristics, treatment modalities, prognosis and risk factors in patients with dual primary carcinoma involving colorectal carcinoma (CRC) combined with primary hepatic carcinoma (PHC).

The clinicopathologic and follow-up data of 40 cases with dual primary CRC and PHC in the Sixth Affiliated Hospital, Sun Yat-sen University from July 2012 to June 2021 were retrospectively analyzed.

Among the 40 cases, 23 cases (57.5%) were diagnosed with simultaneous dual primary cancer and 17 (42.5%) with metachronous dual primary cancer. There were no significant differences in age of onset and clinicopathological characteristics between the two groups. After 14 months (ranging from 2 to 81 months) of follow-up, 31 cases survived. The 2-, 5-year survival rate was 77.6%, 61.0% respectively. The difference in overall survival between patients with CRC as the first primary cancer (27 cases) and patients with PHC as the first primary cancer (13 cases) was not statistically significant (P=0.346). There were no significant differences in the type of the first primary cancer, age of onset, interval of onset and the presence of CRC-related gene mutation on the prognosis of patients.

For patients with dual primary CRC and PHC, the type of the first primary cancer, age of onset, interval of onset, and the presence of CRC-related gene mutation are not independent risk factors affecting the prognosis of patients.