T2a and T2b gallbladder cancer (peritoneal side versus hepatic side)
Since 2017 a gallbladder tumour that has reached the muscle layer is split by which side of the gallbladder it sits on: the free side facing the abdomen (T2a) does better than the side stuck to the liver (T2b).
Overview
Shindoh and colleagues showed in 437 resected patients that hepatic-side T2 tumours carried more vascular, neural and nodal invasion and worse survival (five-year survival 42.6 versus 64.7 percent; hazard ratio 2.7). The eighth edition of the AJCC staging manual (2017) adopted the split as T2a (peritoneal side) and T2b (hepatic side). Meta-analyses confirm the prognostic gap (hazard ratio about 2.1 to 3.2) and suggest liver resection helps T2b but may be unnecessary for T2a, a question no randomised trial has yet answered.
- Pancreatic head (most PDAC)
- Body and tail
- Ampulla
- Islets (pancreatic NET)
- Intrahepatic ducts
- Perihilar (Klatskin)
- Distal bile duct
- Gallbladder
- Nodes: peripancreatic
- Nodes: hepatic hilar
- Nodes: coeliac and superior mesenteric
Most pancreatic cancers arise in the head next to the bile duct, which is why jaundice is the presenting sign; bile duct cancers are named by where along the tree they sit.
- Pancreatic head (most PDAC)
- Body and tail
- Ampulla
- Islets (pancreatic NET)Neuroendocrine carcinoma of the gallbladder (small cell and large cell; under 5 percent)
- Intrahepatic ducts
- Perihilar (Klatskin)
- Distal bile duct
- GallbladderGallbladder adenocarcinoma (about 90 percent; biliary, intestinal, mucinous and other patterns) · Papillary carcinoma of the gallbladder, and its precursor the intracholecystic papillary neoplasm · Mucinous carcinoma of the gallbladder (about 2.5 percent) · Adenosquamous and squamous carcinoma of the gallbladder (about 5 percent) · Neuroendocrine carcinoma of the gallbladder (small cell and large cell; under 5 percent) · Incidental gallbladder cancer found in the cholecystectomy specimen · Carcinoma in situ and dysplasia of the gallbladder (biliary intraepithelial neoplasia; stage 0) · Cystic duct carcinoma (staged with gallbladder cancer)
- peripancreatic
- hepatic hilar
- coeliac and superior mesenteric
Same organ: Pancreatic ductal adenocarcinoma, Biliary tract cancer (cholangiocarcinoma), Intrahepatic cholangiocarcinoma, Extrahepatic cholangiocarcinoma (perihilar and distal), Biliary tract cancer (all types), Neuroendocrine tumours, Pancreatic neuroendocrine tumours, Grade 3 well-differentiated neuroendocrine tumour, Extrapulmonary neuroendocrine carcinoma, Gallbladder adenocarcinoma, Papillary carcinoma of the gallbladder, Mucinous carcinoma of the gallbladder, Adenosquamous and squamous carcinoma of the gallbladder, Neuroendocrine carcinoma of the gallbladder, Incidental gallbladder cancer (found after cholecystectomy), Carcinoma in situ and dysplasia of the gallbladder, Cystic duct carcinoma, Ampullary cancer (ampulla of Vater), Resectable pancreatic ductal adenocarcinoma, Borderline resectable pancreatic ductal adenocarcinoma, Locally advanced unresectable pancreatic ductal adenocarcinoma, Metastatic pancreatic ductal adenocarcinoma, KRAS G12C-mutant pancreatic ductal adenocarcinoma, KRAS wild-type pancreatic ductal adenocarcinoma, BRCA or PALB2-mutant pancreatic ductal adenocarcinoma, Mismatch repair deficient (MSI-high) pancreatic ductal adenocarcinoma, Pancreatic acinar cell carcinoma, Intraductal papillary mucinous neoplasm and other pancreatic cystic precursors, Pancreatoblastoma
Showing the organ this term concerns: Gallbladder cancer.
The prognostic split is solid; the surgical consequence is not. Whether T2a tumours can safely skip liver resection, and whether T2b tumours gain from it, is a randomised or prospective-registry question that nobody has yet run.
Consistent with Kang and colleagues on prognosis, and more optimistic about liver resection for T2b. The adjuvant chemotherapy finding is retrospective and predates gallbladder-specific analysis of BILCAP, but it is a warning that the adjuvant benefit in this disease is not established.
Anatomy alone explains only about two thirds of the ranking of who lives longer; the 2026 staging review makes the same point and argues for molecular and nodal-burden modifiers alongside TNM.
The staging change UK pathology reports now carry. Validation against the US National Cancer Database (Giannis 2021) found the eighth edition no better than the seventh at predicting survival overall.
One of the series that raised the question of sparing the liver resection in T2a disease; only 33 peritoneal-side tumours, so it poses the question rather than settles it.
The study behind the T2a/T2b split adopted by the AJCC eighth edition in 2017, the one staging change in gallbladder cancer that grew from the disease's own anatomy rather than from bile duct cancer.
Similar pages
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