Introduction:About 90% of cholangiocarcinomas are adenocarcinomas with glandular or tubular structures lined by epithelial cells, with no bile production and with a variable degree of differentiation, arising in the background of desmoplastic stroma. The remaining 10% is represented by rarer histological variants of which there is little knowledge regarding the biological behavior, molecular characterization, and sensitivity to the various possible therapies, including molecular-based treatments. Such rare tumors are described only in case reports or small retrospective series because of their exclusion from clinical trials. This national initiative, here presented, aims to address the following knowledge gap: a) how much does histological diversity translate into clinical manifestation variety? b) are those chemotherapy regimens, recommended for conventional biliary tract cancers, potentially active in rare variants? Therefore, epidemiological, pathological, and clinical characterization of series of rare biliary histotypes/variants, for which therapeutic and follow-up data are available, will be collected.Methods:An Italian task force on rare tumors of the biliary tract (IRaBiCa) has been created, whose initiative is a multicenter retrospective study involving 34 Italian cancer centers. Clinical data from approximately 100 patients will be collected and analyzed. Continuous variables will be presented as median ± standard deviation, while categorical variables will be expressed in terms of frequency. Kaplan-Maier analyses will be used to compare disease free, progression free and overall survival, according to the different histotypes.Conclusions:We expect to gather novel data on rare histotypes of biliary tract cancer that will be useful to support their molecular and immunological characterization.

中文翻译：

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意大利罕见胆道癌倡议 (IRaBiCa)：Gruppo Oncologico dell'Italia Meridionale (GOIM) 与 Gruppo Italiano Colangiocarcinoma (GICO) 合作进行的一项多中心观察研究

简介：约 90% 的胆管癌是腺癌，具有腺体或管状结构，内衬上皮细胞，不产生胆汁，具有不同程度的分化，产生于促纤维增生性基质背景。剩下的 10% 是较罕见的组织学变异，人们对这些变异的生物学行为、分子特征以及对各种可能疗法（包括基于分子的治疗）的敏感性知之甚少。这种罕见的肿瘤仅在病例报告或小型回顾性系列中描述，因为它们被排除在临床试验之外。这里提出的这项国家倡议旨在解决以下知识差距：a）组织学多样性在多大程度上转化为临床表现多样性？b) 这些推荐用于传统胆道癌的化疗方案是否可能对罕见变异有效？因此，将收集一系列罕见胆道组织型/变异的流行病学、病理学和临床特征，并提供治疗和随访数据。方法：意大利罕见胆道肿瘤工作组 (IRaBiCa) 已其倡议是一项涉及 34 个意大利癌症中心的多中心回顾性研究。将收集并分析大约 100 名患者的临床数据。连续变量将表示为中位数±标准差，而分类变量将用频率表示。根据不同的组织型，Kaplan-Maier 分析将用于比较无病生存率、无进展生存率和总生存率。结论：我们期望收集有关胆道癌罕见组织型的新数据，这将有助于支持其分子和免疫学特征。