Abstract：
BACKGROUND: In ultra-rare sarcomas (URS) the conduction of prospective, randomized trials is challenging. Data from retrospective observational studies (ROS) may represent the best evidence available. ROS implicit limitations led to poor acceptance by the scientific community and regulatory authorities. In this context, an expert panel from the Connective Tissue Oncology Society (CTOS), agreed on the need to establish a set of minimum requirements for conducting high-quality ROS on the activity of systemic therapies in URS.
METHODS: Representatives from > 25 worldwide sarcoma reference centres met in November 2020 and identified a list of topics summarizing the main issues encountered in ROS on URS. An online survey on these topics was distributed to the panel; results were summarized by descriptive statistics and discussed during a second meeting (November 2021).
RESULTS: Topics identified by the panel included the use of ROS results as external control data, the criteria for contributing centers selection, modalities for ensuring a correct pathological diagnosis and radiologic assessment, consistency of surveillance policies across centers, study end-points, risk of data duplication, results publication. Based on the answers to the survey (55 of 62 invited experts) and discussion the panel agreed on 18 statements summarizing principles of recommended practice.
CONCLUSIONS: These recommendations will be disseminated by CTOS across the sarcoma community and incorporated in future ROS on URS, to maximize their quality and favor their use as control data when results from prospective studies are unavailable. These recommendations could help the optimal conduction of ROS also in other rare tumors.
METHODS: Representatives from > 25 worldwide sarcoma reference centres met in November 2020 and identified a list of topics summarizing the main issues encountered in ROS on URS. An online survey on these topics was distributed to the panel; results were summarized by descriptive statistics and discussed during a second meeting (November 2021).
RESULTS: Topics identified by the panel included the use of ROS results as external control data, the criteria for contributing centers selection, modalities for ensuring a correct pathological diagnosis and radiologic assessment, consistency of surveillance policies across centers, study end-points, risk of data duplication, results publication. Based on the answers to the survey (55 of 62 invited experts) and discussion the panel agreed on 18 statements summarizing principles of recommended practice.
CONCLUSIONS: These recommendations will be disseminated by CTOS across the sarcoma community and incorporated in future ROS on URS, to maximize their quality and favor their use as control data when results from prospective studies are unavailable. These recommendations could help the optimal conduction of ROS also in other rare tumors.
摘要：
背景：在超罕见肉瘤（URS）中，随机试验具有挑战性.来自回顾性观察性研究（ROS）的数据可能是可用的最佳证据。ROS隐含的局限性导致科学界和监管机构的接受度较差。在这种情况下，结缔组织肿瘤学会（CTOS）的专家小组，同意有必要建立一套对URS系统治疗活动进行高质量ROS的最低要求。
方法：来自全球25个肉瘤参考中心的代表于2020年11月开会，确定了一系列主题，总结了ROS在URS中遇到的主要问题。关于这些主题的在线调查已分发给小组；结果通过描述性统计数据进行了总结，并在第二次会议（2021年11月）上进行了讨论。
结果：小组确定的主题包括使用ROS结果作为外部控制数据，贡献中心选择的标准，确保正确的病理诊断和放射学评估的方式，各中心监控政策的一致性，研究终点，数据重复的风险，结果发布。根据对调查的答复(62名受邀专家中的55名)和讨论，小组商定了18项陈述，总结了建议做法的原则。
结论：这些建议将由CTOS在肉瘤社区中传播，并纳入URS的未来ROS中，当前瞻性研究的结果不可用时，最大限度地提高其质量，并支持将其用作对照数据。这些建议可以帮助ROS在其他罕见肿瘤中的最佳传导。
方法：来自全球25个肉瘤参考中心的代表于2020年11月开会，确定了一系列主题，总结了ROS在URS中遇到的主要问题。关于这些主题的在线调查已分发给小组；结果通过描述性统计数据进行了总结，并在第二次会议（2021年11月）上进行了讨论。
结果：小组确定的主题包括使用ROS结果作为外部控制数据，贡献中心选择的标准，确保正确的病理诊断和放射学评估的方式，各中心监控政策的一致性，研究终点，数据重复的风险，结果发布。根据对调查的答复(62名受邀专家中的55名)和讨论，小组商定了18项陈述，总结了建议做法的原则。
结论：这些建议将由CTOS在肉瘤社区中传播，并纳入URS的未来ROS中，当前瞻性研究的结果不可用时，最大限度地提高其质量，并支持将其用作对照数据。这些建议可以帮助ROS在其他罕见肿瘤中的最佳传导。
