Helicobacter species in cancers of the gallbladder and extrahepatic biliary tract

Abstract

Helicobacter species have been found in human bile and biliary tract (BT) tissue and are suspected to cause BT diseases, including gallbladder and extrahepatic cancers, collectively referred to in this work as BT cancers. We conducted a literature review of the epidemiological evidence linking the presence of Helicobacter species in bile or BT biopsies to BT cancers and benign diseases. Reports showed great variability with respect to study methods. Nine studies of BT cancers were identified, all with 30 or fewer BT cancers; eight included cancer-free control subjects and used polymerase chain reaction (PCR) as a means of Helicobacter species detection. In four of these studies, Helicobacter species were detected in patients with BT cancer significantly more frequently than in controls, at least when controls without BT diseases were used. In two studies, no Helicobacter species were detected in either cases or controls. Helicobacter species were also often detected in benign BT diseases such as gallstone disease or chronic cholecystitis. As our current knowledge relies on a few small studies that showed substantial differences, larger studies and more standardised protocols for detecting DNA and antibodies against Helicobacter species are needed to investigate a potential association with BT cancer.

Comparison of media and growth conditions for culturing enterohepaticHelicobacterspecies

“…Enterohepatic species of the genus Helicobacter (EHH) have become increasingly important as emerging pathogens (Collado et al, 2014;Fresia et al, 2017) due to their association with acute gastroenteritis, inflammatory bowel disease (Crohn's disease and ulcerative colitis) and liver, gallbladder and bile ducts diseases (Man et al, 2008;Martel et al, 2009;Bascuñana et al, 2011;Thomson et al, 2011).…”

“…Although EHH are frequently detected in clinical samples by PCR (Fox, 2002;Mateos-Muñoz et al, 2013;Fresia et al, 2017), only occasionally they are isolated using medium and atmospheric conditions designed for Campylobacter spp. According to the Bergey's Manual, there is no ideal method for the isolation of EHH and the recovery of these species is often optimized by the simultaneous use of selective and nonselective procedures .…”

Infection with Helicobacter bilis but not Helicobacter hepaticus was Associated with Extrahepatic Cholangiocarcinoma

“…It is important to note that few studies have addressed the presence of Helicobacter spp. in ECCA using a case-control study design, and those using PCR tests specific for H. hepaticus and H. bilis are even fewer [50]. Among these last studies, some reported a significantly higher frequency of Helicobacter spp.…”

Role of Bacteria in Oncogenesis

“…Eight studies of humans have evaluated the presence of Helicobacter species in biliary tracts of cancer patients versus controls. These studies have had significant differences in their methods of bacterial detection, including culture, DNA amplification, and immunohistochemistry (58,98). Controls have typically comprised subjects with biliary tract diseases such as gallstones or cholecystitis.…”