Second Primary Cancer Development in Patients with Hepatocellular Carcinoma in South Korea: A Nationwide, Population-Based Study, 2002-2013 = Second Primary Cancer Development in Patients with Hepatocellular Carcinoma in South Korea: A Nationwide, Population-Based Study, 2002-2013

다국어 초록 (Multilingual Abstract)

Aims: This study aimed to identify the epidemiologic characteristics for developing second primary cancer (SPC) among patients diagnosed as having hepatocellular carcinoma (HCC).
Methods: This study used a large dataset derived from the National Health Insurance of South Korea from 2002 to 2013. The patients in this study were newly diagnosed with HCC between 2004 and 2006. We excluded the following patients: (i) those who had been treated for any other cancer before diagnosis of HCC; (ii) those who did not undergo CT, MRI, or liver biopsy within 180 days before HCC diagnosis; and (iii) those who were followed up within 180 days since HCC diagnosis. SPC cases were selected by using the ICD-10th; “C” or “D00-D09” or “D37-D48”, applying the criteria after 180 days of HCC diagnosis. Those with “ill-defined (C76-C80)” or “primary multiple sites (C97)” were excluded from the SPC cases. We calculated standardized incidence ratios (SIRs) and used competing risk regression with adjustment for death and consideration of initial treatment with transarterial chemoembolization, radiotherapy, liver transplantation, liver resection, and comorbidities, including diabetes, chronic obstructive pulmonary disease (COPD), chronic kidney disease, cerebral vascular disease, and ischemic heart disease.
Results: We enrolled 24,036 HCC patients from 2004 to 2006, with a mean age of 56.7 years and mean follow-up duration of 4.92 years. Of the patients, 2,270 (9.4%) developed SPC after 180 days of HCC diagnosis. The age-SIRs for SPC among the HCC patients were higher than those for development of cancer among the general population in both men (SIR: 18.56) and women (SIR: 21.16) per 1,000 person-years. Older age (adjusted hazard ratio: 1.11 with a 10-year increase) was an independent risk factor for developing SPC in the HCC patients. However, COPD and diabetes were not independently associated with a risk of SPC.
Conclusions: The incidence of SPC in the HCC patients was much higher than that in the general population, and the risk increased with age. Therefore, surveillance strategies could be formulated for HCC survivors, particularly in older patients.