Aljiffry M, Walsh MJ, Molinari M (2009) Advances in diagnosis, treatment and palliation of cholangiocarcinoma: 1990-2009. World J Gastroenterol, 15(34):4240-4262
Abstract: While the incidence of intra-hepatic CC is increasing, the incidence of extra-hepatic CC is trending down.
Introduction
Cholangiocarcinomas (CC) are malignant tumors originating from epithelial cells lining the biliary tree and gallbladder[1].
Epidemiology
The incidence of CC is rising in most countries and it is the second most common primary malignancy of the liver after hepatocellular carcinoma[1]. In the USA, approximately 5000 new cases are diagnosed every year[11] accounting for almost 3% of all tumors of the gastrointestinal tract[12]. While the incidence of ICC is rising, the occurrence of ECC is trending down[13,14] suggesting that different risk factors may be involved[15]. Caution should be used when interpreting these results as misclassification bias may have influenced these observations[2,16]. In fact, analysis of the Surveillance Epidemiology and End Results database from 1975 until 1999 has shown that most hilar tumors (more than 90%) were classified as ICC[2,16] while ECC were often combined with gallbladder cancers[2,13]. Nevertheless, evidence that ICC and ECC may be dissimilar tumors is supported by the recent discovery that, in vitro, they express diverse cellular proteins and have different cellular shape, doubling time, chromosome karyotype and chemosensitivity[17].
ICC: The estimated age-adjusted incidence rates of ICC in the USA has increased by 165% over the last thirty years (from 0.32 per 100 000 in 1975-1979 to 0.85 per 100 000 in 1995-1999[2,19] accounting for 10% to 15% of all primary hepatic cancers[20]. The average age at presentation is the seventh decade of life[2] with a male to female ratio of 1.5[20]. The mortality rate and incidence of ICC have parallel trends[13] as age-adjusted mortality rate increased from 0.07 per 100 000 in 1973 to 0.69 per 100 000 in 1997[21].
Classification
Anatomical: ICCs arise within the liver parenchyma while ECCs involve the biliary tree within the hepatoduodenal ligament and gallbladder. ECCs are further divided into hilar or distal tumors. Approximately 60% to 70% of CC are located in the hylum, 20% to 30% are ECC, and 5% to 10% are ICC (Figure 2) 24,25].
Pathologic Classification: More than 90% of CC are well- to moderately differentiated adenocarcinomas[26,27] Macroscopically, ICC may develop in solid masses, infiltrate periductal tissues, grow intraductally or have mixed characteristics.
Diagnosis
Clinical Presentation: ICCs are often diagnosed by imaging tests, and rarely during physical exams, as asymptomatic hepatic masses[26].
Computed Tomography(CT)
On CT scans, ICC usually present as hypodense lesions with irregular margins on initial images and a variable degree of delayed venous phase enhancement[86]. These characteristics have been shown to correlate with prognosis as hyperattenuating CC have a more aggressive behavior[91]. Other CT findings of ICC include dilatation and thickening of the peripheral intra-hepatic bile ducts and liver capsular retraction[92]
The sensitivity of triple-phase helical CT in the detection of HCC is in the range of 90% to 100%[92,98] and it is even more sensitive in detecting ICC greater than 1 cm in size[90].
MRI/ MRCP
ICC appear as a hypointense lesion on T1- and hyperintense on T2-weighted images with pooling of contrast within the tumor on delayed pictures as seen with CT[116,117]. In a comparative study the relationship of ICC to the vessels and surrounding organs was more easily evaluated on CT compared to MRI[89].
Staging
ICC: The AJCC staging system for primary liver tumors was based on data provided by patients affected by hepatocellular carcinomas and therefore is not sufficiently accurate for ICC[174]. A new staging system for ICC was proposed by Nathan et al[174] based on the number of tumors, vascular invasion, lymph node status and presence of metastatic disease.
Palliation
Although TACE and TACI with gemcitabine, cisplatin and doxorubicin in different combinations[292] are well tolerated, survival benefits have not been proven in large studies and will require further evidence before becoming widely accepted in the scientific community.
Abstract: While the incidence of intra-hepatic CC is increasing, the incidence of extra-hepatic CC is trending down.
Introduction
Cholangiocarcinomas (CC) are malignant tumors originating from epithelial cells lining the biliary tree and gallbladder[1].
Epidemiology
The incidence of CC is rising in most countries and it is the second most common primary malignancy of the liver after hepatocellular carcinoma[1]. In the USA, approximately 5000 new cases are diagnosed every year[11] accounting for almost 3% of all tumors of the gastrointestinal tract[12]. While the incidence of ICC is rising, the occurrence of ECC is trending down[13,14] suggesting that different risk factors may be involved[15]. Caution should be used when interpreting these results as misclassification bias may have influenced these observations[2,16]. In fact, analysis of the Surveillance Epidemiology and End Results database from 1975 until 1999 has shown that most hilar tumors (more than 90%) were classified as ICC[2,16] while ECC were often combined with gallbladder cancers[2,13]. Nevertheless, evidence that ICC and ECC may be dissimilar tumors is supported by the recent discovery that, in vitro, they express diverse cellular proteins and have different cellular shape, doubling time, chromosome karyotype and chemosensitivity[17].
ICC: The estimated age-adjusted incidence rates of ICC in the USA has increased by 165% over the last thirty years (from 0.32 per 100 000 in 1975-1979 to 0.85 per 100 000 in 1995-1999[2,19] accounting for 10% to 15% of all primary hepatic cancers[20]. The average age at presentation is the seventh decade of life[2] with a male to female ratio of 1.5[20]. The mortality rate and incidence of ICC have parallel trends[13] as age-adjusted mortality rate increased from 0.07 per 100 000 in 1973 to 0.69 per 100 000 in 1997[21].
Classification
Anatomical: ICCs arise within the liver parenchyma while ECCs involve the biliary tree within the hepatoduodenal ligament and gallbladder. ECCs are further divided into hilar or distal tumors. Approximately 60% to 70% of CC are located in the hylum, 20% to 30% are ECC, and 5% to 10% are ICC (Figure 2) 24,25].
Pathologic Classification: More than 90% of CC are well- to moderately differentiated adenocarcinomas[26,27] Macroscopically, ICC may develop in solid masses, infiltrate periductal tissues, grow intraductally or have mixed characteristics.
Diagnosis
Clinical Presentation: ICCs are often diagnosed by imaging tests, and rarely during physical exams, as asymptomatic hepatic masses[26].
Computed Tomography(CT)
On CT scans, ICC usually present as hypodense lesions with irregular margins on initial images and a variable degree of delayed venous phase enhancement[86]. These characteristics have been shown to correlate with prognosis as hyperattenuating CC have a more aggressive behavior[91]. Other CT findings of ICC include dilatation and thickening of the peripheral intra-hepatic bile ducts and liver capsular retraction[92]
The sensitivity of triple-phase helical CT in the detection of HCC is in the range of 90% to 100%[92,98] and it is even more sensitive in detecting ICC greater than 1 cm in size[90].
MRI/ MRCP
ICC appear as a hypointense lesion on T1- and hyperintense on T2-weighted images with pooling of contrast within the tumor on delayed pictures as seen with CT[116,117]. In a comparative study the relationship of ICC to the vessels and surrounding organs was more easily evaluated on CT compared to MRI[89].
Staging
ICC: The AJCC staging system for primary liver tumors was based on data provided by patients affected by hepatocellular carcinomas and therefore is not sufficiently accurate for ICC[174]. A new staging system for ICC was proposed by Nathan et al[174] based on the number of tumors, vascular invasion, lymph node status and presence of metastatic disease.
Palliation
Although TACE and TACI with gemcitabine, cisplatin and doxorubicin in different combinations[292] are well tolerated, survival benefits have not been proven in large studies and will require further evidence before becoming widely accepted in the scientific community.
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