Published online Nov 27, 2020. doi: 10.4254/wjh.v12.i11.1020
Peer-review started: April 15, 2020
First decision: June 4, 2020
Revised: July 25, 2020
Accepted: October 12, 2020
Article in press: October 12, 2020
Published online: November 27, 2020
Processing time: 222 Days and 23.7 Hours
Combined hepatocellular and cholangiocarcinoma (HCC/CC) is a rare primary hepatic malignancy which carries a poor prognosis due to its aggressive nature. Few centers have enough cases to draw definitive conclusions and there is limited understanding of prognosis. Given the rarity of HCC/CC, an analysis of large national cancer database was needed to obtain larger number of HCC/CC cases.
To identify associated factors for 5-year survival of HCC/CC.
We conducted a retrospective study of The Surveillance, Epidemiology, and End Results (SEER) database obtained from SEER*Stat 8.3.6 software. Previously defined histology code 8180 for the International Classification of Disease for Oncology, 3rd edition was used to identify HCC/CC cases from 2004 to 2015. We collected demographics, American Joint Committee on Cancer (AJCC) stage, treatment, tumor size, and survival data. These data were converted to categorical variables. The Shapiro-Wilk normality test was used to assess normal distribution. Mann-Whitney U test was used to compare continuous variables without normal distribution, and t-test was used to compare continuous variables with a normal distribution. The Kaplan-Meier survival curve analyzed 5-year survival. Univariate and multivariate logistic regression model was used to analyze factors associated with 5-year survival. Multivariate Cox proportional hazard regression was done on 5-year survival. We defined P < 0.05 was statistically significant.
We identified 497 patients with the following characteristics: Mean age 62.4 years (SD: 11.3), 149 (30.0%) were female, racial distribution was: 276 (55.5%) white, 53 (10.7%) black, 84 (16.9%) Asian and Pacific Islander (API), 77 (15.5%) Hispanic, and 7 (1.4%) others or unknown. Stage I/II disease occurred in 41.5% and tumor size < 50 mm was seen in 35.6% of patients. Twenty-four (4.8%) received locoregional therapy (LRT), 119 (23.9%) underwent resection, and 50 (10.1%) underwent liver transplantation. The overall median survival was 6 mo [Interquartile range (IQR): 1-22]. After multivariate logistic regression, tumor size < 50 mm [Odds ratios (OR): 2.415, P = 0.05], resection (OR: 12.849, P < 0.01), and transplant (OR: 27.129, P < 0.01) showed significance for 5-year survival. Age > 60, sex, race, AJCC stages, metastasis, and LRT were not significant. However, API vs white showed significant OR of 2.793 (CI: 1.120-6.967). Cox proportional hazard regression showed AJCC stages, tumor size < 50 mm, LRT, resection, and transplant showed significant hazard ratio.
HCC/CC patients with tumor size < 50 mm, resection, and transplant were associated with an increase in 5-year survival. API showed advantageous OR and hazard ratios over white, black.
Core Tip: Combined hepatocellular and cholangiocarcinoma (HCC/CC) is a rare primary hepatic malignancy which carries a poor prognosis due to its aggressive nature. Few centers have enough cases to draw definitive conclusions and there is limited understanding of prognosis. This analysis of Surveillance, Epidemiology, and End Results database comprised of 497 patients. HCC/CC patients with tumor size < 50 mm, resection, and transplant were associated with an increase in 5-year survival. Asian and Pacific Islander (API) showed advantageous odds ratios and hazard ratios over white, black. Elucidation of better prognosis on API are needed in the future studies.