Cancers of the gallbladder and biliary tract are uncommon malignancies in the United States with a combined incidence of less than 8,000 new cases per year, about 5,000 of which are gallbladder cancer and about 2,000 to 3,000 of which are cholangiocarcinomas, including intrahepatic, hilar, and distal bile duct cancers. For gallbladder cancer with mucosa-confined disease, the 5-year survival rate is approximately 32%, and for advanced disease, less than 10% of patients survive longer than 1 year.
Yee and colleagues provide a thorough and comprehensive review of the natural history, epidemiology, therapeutic options, and prognosis of biliary tree cancers. Several points from their article will be highlighted for discussion, including epidemiology, surgical management, adjuvant therapy, and management of advanced disease.
The epidemiology of gallbladder cancer is characterized by a striking ethnic variation and female preponderance. The highest incidence rates have been observed among Bolivians, but Hispanics, North American Indians, and Mexican Americans also have a high incidence of this disease. These incidences correlate directly with the prevalence of cholelithiasis. Cholangiocarcinoma represents a relatively rare malignancy. The etiology of these cancers is not well understood; however, chronic inflammatory processes, activation of oncogenes, functional loss of tumor-suppressor genes, dysregulation of cell proliferation, and cell apoptotic mechanisms have been identified as contributors to the development of cholangiocarcinomas.[3,4]
It has been suggested that a sequence of "intestinal metaplasia-dysplasia-carcinoma" occurs in the development of biliary tract cancers. After the manifestation of invasive disease, therapeutic strategies other than surgery are limited, suggesting that interruption of the pathogenic cascade in earlier-stage disease may offer potential.
For patients with biliary tract cancers, complete surgical resection represents the only known curative modality. Several recent changes in the surgical management of these cancers have led to improved outcomes for earlier-stage disease. Perhaps the most important advance has been the evolution of improved imaging techniques. High-quality, contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI) with or without angiography, color Doppler ultrasonography, and endoscopic ultrasound can greatly enhance visualization of the local vascular anatomy and assist the assessment of resectability. Specifically with regard to cholangiocarcinoma, liver resection (partial hepatectomy) in conjunction with en bloc removal of the malignancy may increase the likelihood of complete gross tumor resection (R0) and decrease the likelihood of local tumor recurrence.