#Yi Chen and Liyun Huang contributed equally to this work
Intrahepatic cholangiocarcinoma (ICC), which originates from the secondary bile duct and its branch bile duct epithelium, accounts for 10%–15% of primary liver cancer and is now becoming a highly aggressive malignant tumor [
At present, numerous factors identified by clinicians can influence the prognosis of ICC patients after resection [
In this study, preoperative serological indicators and postoperative pathological indicators were included to construct a nomogram to predict the prognosis of postoperative ICC patients. To the best of our knowledge, this is the first nomogram statistical method used to evaluate the prognosis of ICC patients by incorporating the pathological classification of ICC.
A retrospective study was performed on a total of 127 patients diagnosed with ICC from January 2015 to December 2019 at Mengchao Hepatobiliary Hospital of Fujian Medical University (Fuzhou, China). The inclusion criteria were as follows: (1) patients with radical resection of intrahepatic bile duct tumors at our hospital (R0) and complete resection of liver tumors, (2) patients with full records of clinicopathological data, (3) postoperatively histopathologically proven ICC, (4) no history of other anti-tumor therapies before surgery, and (5) no history of other malignancies. Exclusion criteria included the following: (1) death within 30 days after surgical operation and (2) combined hepatocellular carcinoma–cholangiocarcinoma. This study was approved by the ethics committee at Mengchao Hepatobiliary Hospital of Fujian Medical University (Approval No. 2021–044–01). The clinical information and characteristics were recorded and analyzed after written consent was obtained from the patients and their families.
After baseline history-taking and a detailed physical examination, blood was obtained from patients in order to detect serological indicators, including hepatitis B surface antigen (HBsAg), hepatitis B virus DNA level, anti-hepatitis C virus (HCV) antibody, serum albumin, total bilirubin, alanine transaminase, carbohydrate antigen 125 (CA125), carbohydrate antigen 19-9 (CA 19-9), and carcinoembryonic antigen (CEA). All patients were assessed with contrast-enhanced computed tomography or magnetic resonance imaging, and positron emission tomography was chosen to determine whether intrahepatic or extrahepatic metastases existed. According to tumor features and anatomy of the liver, partial liver resection combined with regional lymph node dissection in the hepatoduodenal ligament and retropancreatic and/or para-aortic lymph nodes was performed.
Serial slides were cut from representative formalin-fixed paraffin-embedded (FFPE) samples, stained with hematoxylin and eosin (H&E), and then observed under the microscope by 2 independent pathologists. Tumor pathological indicators were recorded, including tumor size, number, tumor envelope, gross classification (mass type, peritubular-infiltration type, and intratubular-growth type), tumor differentiation (poorly differentiated, moderately differentiated, and well-differentiated), extrahepatic metastasis, bile duct invasion, lymph node metastasis, and liver cirrhosis. According to histologic appearance and immunohistochemical index, ICC was sub-classified into large and small duct types [
Since IDH1/2 and KRAS mutations were reported to be the most frequent genetic alterations according to several large-scale genomic analyses, tumor tissues were macro-dissected from FFPE tissue blocks. Then, the total DNA of ICC tissues was extracted using a commercial kit (DNB400-50RXN; Merck, Darmstadt, Germany) according to the manufacturer’s instructions. This study focused on the mutation hotspots of exon 4 at codon 132 of IDH1, exon 4 at codon 172 of IDH2, and exon 2 of KRAS by polymerase chain reaction (PCR). The primer pairs used are as follows: IDH1-R132: F: 5’-GATGAGAAGAGGGTTGAGGAGTT-3’ and R: 5’-TACCTTGCTTAATGGGTGTAGATAC-3’; IDH2-R172: F: 5’-AGCTGAAGAAGATGTGGAAAAGTC-3’ and R: 5’-TTTGGGGTGAAGACCATTTTG-3’; and KRAS: F: 5’-ACGTCTGCAGTCAACTGGAATT-3’ and R: 5’-TCTGTATCAAAGAATGGTCCTGC-3’. The PCR productions were analyzed with the 3730xl DNA Analyzer (Thermo Fisher Scientific, Waltham, MA, USA).
ICC patients underwent follow-up examinations every 3 months after surgery. At each post-surgery visit, physical examinations were carried out. Blood was collected to detect serum levels of CA19-9, CA125, and CEA, and contrast-enhanced CT or magnetic resonance imaging was also performed. When tumor recurrence or metastasis was suspected, contrast-enhanced CT or magnetic resonance imaging was performed earlier. In this study, the endpoint of follow-up was defined as tumor recurrence confirmed by radiologic imaging or death caused by ICC. Overall survival (OS) was defined as the interval between the date of surgery and death or the last date of follow-up.
Categorical variables are displayed as mean ± standard deviation values, and categorical variables are expressed as frequencies. All recorded variables associated with prognosis were first analyzed by univariate COX regression analysis. Subsequently, the potential variables associated with prognosis at a significant level by univariate COX regression analysis were further enrolled in multivariate COX regression analysis to verify the independent risk factors. Nomogram was plotted based on these independent differential factors using the rms package in R version 4.0.3 (
The basic characteristics of the entire cohort are shown in
Factors | No. of patients | % |
---|---|---|
Age, years (mean ± SD) | 61.19 ± 11.02 | |
Sex | ||
Male | 68 | 53.54 |
Female | 59 | 46.46 |
HBV positive (yes |
42 | 33.07 |
CA199 (median, range) | 73.93, 0.1–1000 | |
CA125 (median, range) | 25.12, 0.1–1000 | |
CEA (median, range) | 3.00, 0.7–200 | |
Maximum diameter | ||
<5 cm | 56 | 44.09 |
≥5 cm | 71 | 55.91 |
Tumor number | ||
Single | 96 | 75.59 |
Multiple | 31 | 24.41 |
Visual classification | ||
Periductal infiltration | 35 | 27.56 |
Intraductal growth type | 60 | 47.24 |
Mass-forming type | 32 | 25.20 |
Tumor differentiation | ||
Poor | 38 | 29.92 |
Moderate | 67 | 52.76 |
Well | 21 | 16.54 |
Extrahepatic metastasis | 28 | 22.05 |
Vascular invasion | 67 | 52.76 |
Bile duct invasion | 20 | 15.75 |
lymph node metastasis | 46 | 36.22 |
Liver cirrhosis | 22 | 17.32 |
Large-duct ICC | 47 | 37.01 |
IDH1/2 mutation | 26 | 20.47 |
KRAS mutation | 17 | 13.39 |
Abbreviations: SD, standard deviation; HBV, hepatitis B virus; NCAM, neural cell adhesion molecule; CA19-9, carbohydrate antigen 19-9; CA125, carbohydrate antigen 125; CEA, carcinoembryonic antigen; IDH1/2, isocitrate dehydrogenase 1/2; KRAS, Kirsten rat sarcoma viral oncogene homolog 2.
As showed in
Factors | Univariate COX regression | Multivariate COX regression | ||||
---|---|---|---|---|---|---|
HR | 95% CI | HR | 95% CI | |||
Age (mean ± SD) | 1.382 | 0.819–2.332 | 0.225 | |||
Gender (male |
1.438 | 0.845–2.446 | 0.180 | |||
HBV positivity (yes |
1.000 | 1.000–1.1001 | 0.912 | |||
CA19-9 (mean ± SD) | 1.002 | 1.001–1.002 | 1.000 | 0.999–1.001 | 0.579 | |
CA125 (mean ± SD) | 1.000 | 1.000–1.1001 | 0.180 | |||
CEA (high |
1.013 | 1.008–1.018 | 1.010 | 1.003–1.017 | ||
Bilirubin level (high |
1.408 | 0.598–4.761 | 0.473 | |||
Maximum diameter (≥5 cm |
1.25 | 1.163–1.344 | 1.303 | 1.176–1.443 | ||
Tumor number (multiple |
2.442 | 1.420–4.119 | 2.094 | 1.153–3.801 | ||
Visual classification (periductal infiltration/intraductal growth type |
1.755 | 1.012–3.045 | 1.492 | 0.761–2.923 | 0.244 | |
Tumor differentiation (well/moderate |
0.372 | 0.148–0.933 | 0.837 | 0.317–2.206 | 0.718 | |
Extrahepatic metastasis (yes |
2.359 | 1.347–4.134 | 0.670 | 0.346–1.297 | 0.235 | |
Vascular invasion (yes |
1.274 | 0.756–2.147 | 0.363 | |||
Bile duct invasion (yes |
0.697 | 0.316–1.536 | 0.371 | |||
Lymph node metastasis (yes |
1.412 | 0.839–2.377 | 0.194 | |||
Liver cirrhosis (yes |
0.609 | 0.298–1.242 | 0.172 | |||
Large duct type ICC (yes |
3.677 | 2.154–6.277 | 2.831 | 1.298–6.175 | ||
IDH1/2 mutation (yes |
0.592 | 0.286–1.208 | 0.182 | |||
KRAS mutation (yes |
0.801 | 0.382–1.806 | 0.609 |
Abbreviations: SD, standard deviation; HBV, hepatitis B virus; NCAM, neural cell adhesion molecule. CA19-9, carbohydrate antigen 19-9; CA125, carbohydrate antigen 125; CEA, carcinoembryonic antigen; IDH1/2, isocitrate dehydrogenase 1/2; KRAS, Kirsten ratsarcoma viral oncogene homolog 2.
The prognostic nomogram that integrated all significant independent factors for OS during univariate and multivariate COX regression is shown in
The typical morphologic spectrum of large-and small-duct subtypes of ICC is shown in
In addition, patients with large-duct ICC had a significantly worse recurrence-free and overall prognostic outcome than those with small-duct ICC (
Despite the lower incidence in liver cancers, intrahepatic cholangiocarcinoma (ICC) has a poorer prognosis. Therefore, early prediction of postoperative prognosis is significant in predicting postoperative recurrence and early intervention in key populations. Currently, several studies have been carried out to predict the prognosis of ICC patients by constructing a nomogram statistical model. It was found that indicators, including lymph node metastasis, tumor size, tumor stage, and serum CA19-9, had a large impact on the clinical outcome of ICC patients. Despite the significant role of pathological subtypes in ICC, none of these studies included the pathological subtypes of ICC into the nomogram model. Hence, we included preoperative serological indicators, postoperative pathological characteristics, and pathological staging factors into univariate and multivariate regression analyses in the current study. Additionally, CEA, large-duct ICC, multiple tumors, and tumors with diameters >5 cm were all incorporated into the nomogram model to predict the 1-year and 3-year survival of ICC patients after radical resection. Our results suggested that the nomogram model has good predictive performance in predicating ICC prognosis.
Due to its insidious onset and poor prognosis, ICC is prone to recurrence after surgery. The 5-year survival rate and 5-year recurrence rate of patients undergoing ICC surgery in our hospital were 40.30% and 57.01%, respectively, which were slightly higher than rates at other centers [
The diameter of tumors has always been a prognostic factor of concern among clinical workers, but the definite impact of various tumor sizes on prognosis remains inconclusive [
As a result of significant tissue heterogeneity, ICC presents different growth patterns [
In conclusion, we provide a new nomogram model that can improve the predictive efficiency of prognosis for ICC patients, and postoperative subclassification of ICC is of great significance to the prognosis of ICC.
We thank LetPub (
Intrahepatic cholangiocarcinoma
Hepatitis B virus
Neural cell adhesion molecule
Carbohydrate antigen 19-9
Carbohydrate antigen 125
Carcinoembryonic antigen
Isocitrate dehydrogenase 1/2
Kirsten ratsarcoma viral oncogene homolog 2