Nomograms Predicting Long-Term Overall Survival and Cancer-Speci�c Survival in Metastatic Hepatocellular Carcinoma Patients

Background This study aims to evaluate the clinicopathological characteristics of metastatic hepatocellular carcinoma (HCC) patients and develop nomograms to predict their long-term overall survival (OS) and cancer-speci�c survival (CSS). Methods Information on metastatic HCC from 2010 to 2015 was retrieved from the Surveillance, Epidemiology and End Results (SEER) program of the National Cancer Institute. The metastatic HCC patients were divided into a long-term survival (LTS) group and a short-term survival (STS) group with 1 year selected as the cut-off value. Then, we compared the demographic and clinicopathological features between the two groups. Next, all patients were randomly divided into a training group and validation group at a 7:3 ratio. Univariate and multivariate Cox regression analyses were used to identify potential predictors for OS and CSS in the training group, and nomograms of OS and CSS were established. These predictive models were further validated in the validation group. A total of 2163 patients were included in the current study according to the inclusion and exclusion criteria. Patients with characteristics including lower T stage and N stage; treatment with surgery, radiation or chemotherapy; no lung metastasis; and AFP negative status showed better survival. The concordance index (C-index) of the OS nomogram was 0.72 based on 9 variables. The C-index of the CSS nomogram was 0.71 based on 8 variables. These nomograms may help clinicians make better treatment recommendations for metastatic HCC patients. novel surgical techniques, ablation treatment, transcatheter arterial chemoembolization (TACE), and liver transplantation, and the survival of patients has been largely improved. However, for metastatic HCC patients, the 5-year survival rate is less than 3.1% (4) . At present, there is no satisfactory clinical model to predict the prognosis of these patients. from a total of 18 population-based registries there no detailed information about speci�c metastasis sites in the SEER database we selected metastatic HCC patients from to 2015. A series of exclusion criteria was applied to �lter the data: (1) patients with M0 in the M stage or unknown status; (2) patients with unknown status of bone metastasis, brain metastasis, lung metastasis, and distant lymph node metastasis; (3) patients with unknown race, marital status, tumor size and alpha fetoprotein (AFP); (4) patients under 18 years of age; (5) patients with inactive follow-up; and (6) patients with information collected from autopsy or death certi�cates. A total of 15 variables, including age, race, gender, marital status, T stage, N stage, surgery information, radiation therapy, chemotherapy, tumor size, distant lymph node metastasis, bone metastasis, brain metastasis, lung metastasis and AFP, were selected to construct prediction models for the OS and CSS of patients. Then, the patients were divided into two groups, the short-term survival (STS) group and the long-term survival (LTS) group, with 1 year selected as the cutoff value. STS was de�ned as a survival time less than 1 year. LTS was de�ned as a survival time equal to or longer than 1 year. SEER Stat software (SEER-Stat 8.5.6) was used to extract the data. In our study, OS was de�ned as the time from diagnosis to death for any reason. CSS was de�ned as the time from diagnosis to death from HCC. The survival time of HCC patients with distant metastasis ranged from 0 to 82 months in the SEER database. The following formula shows how survival time was calculated. There were 83 (30.3%) and 624 (33%) patients with distant lymph node metastasis, 79 (28.8%) and 528 (28.0%) patients with bone metastasis, 5 (1.8%) and 38 (2%) patients with brain metastasis, and 76 (27.7%) and 791 (41.9%) patients with lung metastasis in the LTS group and STS group, respectively. The results showed that patients in the STS group had higher lung metastasis (P < 0.001) rates than those in the LTS group. However, there was no signi�cant difference in distant lymph node metastasis (P < 0.404), bone metastasis (P < 0.817) or brain metastasis (P < 1.000).