Second Primary Malignancies in Hepatocellular Cancer - A US Population-based Study

A second primary malignancy is a serious long-term complication in cancer survivors. The aim of this study was to evaluate the risk of second primary malignancies in patients with hepatocellular carcinoma (HCC).

We selected adult patients (≥18 years) diagnosed with HCC from the National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) 13 database. We calculated the risk of second primary malignancies in these patients using multiple primary standardized incidence ratio (MP-SIR) session of SEER* stat software. Second primary malignancy was defined as a metachronous malignancy diagnosed 6 months or more after an index HCC.

A total of 15,296 patients with a diagnosis of primary HCC were reported in the SEER 13 registry during January 1992 to December 2011. A total of 446 (2.83%) developed 466 second primary malignancies with an observed/expected ratio of 10.07 (95% confidence interval=0.97-1.17, p=0.16) and absolute risk of 7.17 per 10,000 population. Risk of stomach and of thyroid cancer were significantly increased among older patients. Risk of lung cancer and of hepatobiliary cancer were significantly higher compared to that of the general population after two years of latency.

Risk of specific second primary malignancies in adult patients with HCC depends on age of the patient and latency.