Clinicopathological features
From 2005 to 2015, total of 894 cases underwent hepatectomy for primary liver tumors. Sixteen patients with cHCC-CCAs accounted for 19 cases that received hepatectomy (2.1%); 3 of the 16 cHCC-CCA patients underwent repeated hepatectomy (15.8%). Seven hundred and forty-two cases were HCCs, 121 cases were iCCAs, and 12 cases were other primary liver tumors, including malignant lymphoma, hepatic carcinosarcoma, and hepatic neuroendocrine tumor. One hundred and thirty-three of the 742 HCC patients (17.9%) and 11 of the 121 iCCA patients (9.0%) underwent repeated hepatectomy. During the same period of the study, three patients underwent living-donor liver transplantation for cHCC-CCA and were excluded from this study.
The clinicopathological features of cHCC-CCA, HCC, and iCCA are summarized in Table 1. HCC was more common in men than in women, and more patients had a worse liver function with HCC than those with iCCA. Although more than 90% patients with iCCA were negative for hepatitis B surface antigen (HBsAg), 15.8% of patients with cHCC-CCA and 19.8% of patients with HCC were positive for HBsAg. More than 80% patients with iCCA were negative for hepatitis C virus antibody (HCV-Ab), whereas more than 40% of patients with cHCC-CCA and HCC were positive for HCV-Ab. The preoperative CA19-9 levels in the iCCA patients were significantly higher than those in the cHCC-CCA or HCC patients. Patterns of viral markers and tumor markers in the cHCC-CCA patients more closely resembled those of HCC patients than those of iCCA patients. All patients with cHCC-CCA had a single cHCC-CCA tumor nodule, and 4 of the 16 cHCC-CCA patients had synchronous HCC tumor nodules. There were no significant differences in the rates of major portal vein or hepatic vein invasion among the three groups. However, the frequencies of major biliary tract invasion in cHCC-CCA and iCCA (36.8% and 18.2%, respectively) were higher than that in HCC (5.0%). At the site of the invasion into the major biliary tract of the seven cHCC-CCA patients, three had cHCC-CCA tumors, two had HCC tumors, one had an iCCA tumor, and one had an indeterminate pathology. The surgical procedures for cHCC-CCA, including the presence or absence of resection of extra-hepatic bile duct and/or lymph node dissection, were similar to those for HCC, as the preoperative diagnosis of the cHCC-CCA patients was often HCC.
Prognosis
The overall survival (OS) was compared among cHCC-CCA, HCC, and iCCA patients (Figure 1; left panel). The 5-year OS values of the cHCC-CCA, HCC, and iCCA patients were 44.7%, 56.6%, and 38.5%, respectively. The median survival times (MSTs) of the cHCC-CCA, HCC, and iCCA patients were 50.5, 72.2, and 41.7 months, respectively. The patients with iCCA had a worse prognosis than those with HCC with statistical significance (p=0.0029). The recurrence-free survival (RFS) was also compared among the three groups (Figure 1; right panel). The 5-year RFS values of the cHCC-CCA, HCC, and iCCA patients were 12.2%, 28.7%, and 32.9%, respectively. The median RFS values of the cHCC-CCA, HCC, and iCCA patients were 12.8, 21.3, and 20.3 months, respectively. There were no significant differences among the three groups.
Treatment of recurrent cHCC-CCA
Tumor recurrences and/or metastases were confirmed using imaging examinations, such as CT or MRI, and occasionally pathological examinations. The liver was the most common site of tumor recurrence among the three tumor groups (Table 2). Although the lymph nodes were the second-most common site of recurrence in both cHCC-CCA and iCCA, lymph node metastasis was less frequent in HCC. Two of the three cHCC-CCA patients with lymph node recurrences had metastases in the hepatoduodenal ligament. The treatment modalities for recurrent cHCC-CCA are summarized in Table 3. The majority of the recurrent cHCC-CCA patients were treated according to HCC recurrence.
Pathological patterns of cHCC-CCA recurrence
Pathological examinations were performed in 6 patients, and 10 samples were obtained for recurrent and/or metastatic tumors. The pathological patterns and sites of cHCC-CCA recurrence in the six patients are summarized in Table 4. Four of the patients (B, C, D, and F) had recurrent tumors of cHCC-CCA. The main component of the primary tumor in patient A was CCA, and its lymph node recurrence was CCA. However, the main component of the primary tumor in patient E was HCC, and its subsequently repeated liver recurrences were HCC.