{"entity":{"id":"t2a-versus-t2b","kind":"term","name":"T2a versus T2b gallbladder cancer (peritoneal side versus hepatic side)","aka":["T2a gallbladder cancer","T2b gallbladder cancer","Hepatic-side T2","Peritoneal-side T2","T2 tumour location","Hepatic-side gallbladder cancer","Peritoneal-side gallbladder cancer"],"tldr":"Two labels for a gallbladder cancer that has grown through the muscle layer but is still inside the gallbladder. T2a sits on the free side facing the abdominal cavity; T2b sits on the side pressed against the liver, spreads to nodes and vessels more often and roughly doubles the risk of dying, so the surgeon removes more liver for it.","summary":"The AJCC and UICC 8th edition (2017) split T2 by tumour location: T2a invades the perimuscular connective tissue on the peritoneal side without reaching the serosa, T2b on the hepatic side without liver invasion (CRUK stages and grades). The split rests on an international series of 437 resected patients: among 252 with T2 disease, hepatic-side tumours (99) had more vascular invasion (51 versus 19 percent), neural invasion (33 versus 8 percent) and nodal metastasis (40 versus 17 percent) than peritoneal-side tumours (153), and tumour location predicted recurrence pattern and survival (Shindoh 2015). A 2022 meta-analysis of 15 studies and 2,531 patients (1,332 T2a, 199 T2b classified) found overall survival significantly worse in T2b (hazard ratio 2.18) with more recurrence, and liver resection appeared to improve survival in T2b (Alrawashdeh 2022). Validation studies are mixed: a Korean series found T1b and T2a, and T2b and T3, hard to separate and suggested dropping the subcategories (Sung 2020), and the National Cancer Database validation called for prospective confirmation (Giannis 2021). In practice T2b is the stage at which a formal liver resection (segments IVb and V) is most argued for.","asOf":"2026-09-24","wikipedia":"https://en.wikipedia.org/wiki/Gallbladder_cancer","links":[{"label":"CRUK: stages and grades of gallbladder cancer","url":"https://www.cancerresearchuk.org/about-cancer/gallbladder-cancer/stages-and-grades"},{"label":"Shindoh, Ann Surg 2015: tumour location in T2 gallbladder cancer (hepatic versus peritoneal side)","url":"https://doi.org/10.1097/sla.0000000000000728"},{"label":"Alrawashdeh, HPB 2022: meta-analysis of T2a and T2b gallbladder cancer","url":"https://doi.org/10.1016/j.hpb.2021.12.019"},{"label":"Sung, Cancer Res Treat 2020: validation of the AJCC 8th edition for gallbladder cancer","url":"https://doi.org/10.4143/crt.2019.271"},{"label":"Giannis, Cancers 2021: AJCC 8th edition validation in the National Cancer Database","url":"https://doi.org/10.3390/cancers13030547"}],"tags":["gallbladder","biliary"],"related":[],"cancers":["gallbladder","gallbladder-adenocarcinoma"],"sections":[],"technologies":[],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":["tnm-staging","segment-ivb-v-resection","radical-cholecystectomy"],"trials":[],"people":[],"bottlenecks":[],"keyPapers":["paper-shindoh-t2-gallbladder-cancer-tumour-location-ann-surg-2015","paper-kang-t2-gallbladder-cancer-location-meta-analysis-jcm-2021","paper-khan-t2-gallbladder-cancer-liver-resection-meta-analysis-updates-surg-2021","paper-lee-t2-gallbladder-cancer-surgical-strategy-aso-2015","paper-chun-ajcc-8th-edition-hepatobiliary-aso-2018"],"journals":[],"dependsOn":[],"notes":["Evidence: five-year survival 42.6 versus 64.7 percent for hepatic-side versus peritoneal-side T2 tumours in Shindoh's 437 patients (hazard ratio 2.7); meta-analyses put the prognostic gap at a hazard ratio of about 2.1 to 3.2 and suggest liver resection helps T2b but may be unnecessary for T2a (Kang 2021; Khan 2021), a question no randomised trial has yet answered."],"category":"Pathology"},"route":"/terms/t2a-versus-t2b/","neighbours":{"cancer":[{"id":"gallbladder-adenocarcinoma","kind":"cancer","name":"Gallbladder adenocarcinoma","route":"/cancers/gallbladder-adenocarcinoma/"},{"id":"gallbladder","kind":"cancer","name":"Gallbladder cancer","route":"/cancers/gallbladder/"}],"term":[{"id":"radical-cholecystectomy","kind":"term","name":"Radical (extended) cholecystectomy","route":"/terms/radical-cholecystectomy/"},{"id":"segment-ivb-v-resection","kind":"term","name":"Segment IVb and V liver resection (versus wedge resection)","route":"/terms/segment-ivb-v-resection/"},{"id":"tnm-staging","kind":"term","name":"TNM staging","route":"/terms/tnm-staging/"}],"paper":[{"id":"paper-chun-ajcc-8th-edition-hepatobiliary-aso-2018","kind":"paper","name":"8th Edition of the AJCC Cancer Staging Manual: Pancreas and Hepatobiliary Cancers","route":"/key-papers/paper-chun-ajcc-8th-edition-hepatobiliary-aso-2018/"},{"id":"paper-kang-t2-gallbladder-cancer-location-meta-analysis-jcm-2021","kind":"paper","name":"Prognostic Significance of Tumor Location in T2 Gallbladder Cancer: A Systematic Review and Meta-Analysis","route":"/key-papers/paper-kang-t2-gallbladder-cancer-location-meta-analysis-jcm-2021/"},{"id":"paper-lee-t2-gallbladder-cancer-surgical-strategy-aso-2015","kind":"paper","name":"Surgical Strategy for T2 Gallbladder Cancer According to Tumor Location","route":"/key-papers/paper-lee-t2-gallbladder-cancer-surgical-strategy-aso-2015/"},{"id":"paper-khan-t2-gallbladder-cancer-liver-resection-meta-analysis-updates-surg-2021","kind":"paper","name":"Tumor location and concurrent liver resection, impact survival in T2 gallbladder cancer: a meta-analysis of the literature","route":"/key-papers/paper-khan-t2-gallbladder-cancer-liver-resection-meta-analysis-updates-surg-2021/"},{"id":"paper-shindoh-t2-gallbladder-cancer-tumour-location-ann-surg-2015","kind":"paper","name":"Tumor location is a strong predictor of tumor progression and survival in T2 gallbladder cancer: an international multicenter study","route":"/key-papers/paper-shindoh-t2-gallbladder-cancer-tumour-location-ann-surg-2015/"},{"id":"paper-giannis-ajcc8-gallbladder-staging-validation-cancers-2021","kind":"paper","name":"Validation of the 8th Edition American Joint Commission on Cancer (AJCC) Gallbladder Cancer Staging System: Prognostic Discrimination and Identification of Key Predictive Factors","route":"/key-papers/paper-giannis-ajcc8-gallbladder-staging-validation-cancers-2021/"}],"roadmap":[{"id":"gallbladder-cancer-roadmap","kind":"roadmap","name":"Gallbladder cancer roadmap: from a chance finding at gallstone surgery to a disease with its own trials","route":"/roadmaps/gallbladder-cancer-roadmap/"}],"idea":[{"id":"idea-gbc-t2a-spare-liver-resection-trial","kind":"idea","name":"A trial of sparing the liver resection in peritoneal-side (T2a) gallbladder cancer","route":"/ideas/idea-gbc-t2a-spare-liver-resection-trial/"}],"technology":[{"id":"gallbladder-cancer-surgery","kind":"technology","name":"Surgery for gallbladder cancer: simple versus radical cholecystectomy, re-resection and lymphadenectomy","route":"/technologies/gallbladder-cancer-surgery/"}]}}