Purpose: Three prospective observational studies (Italy, the Netherlands, France) on active surveillance (AS) in patients with extra-abdominal desmoid-type fibromatosis (DTF) support AS as a frontline approach. Identifying prognostic factors for the failure of AS will help determine the strategy. The aim of this study was to investigate the prognostic impact of clinical and molecular variables in a larger series. Experimental design: Data available as of January 31st, 2024, from the three studies, in which patients were followed for ≥3 years, were pooled. Patients ≥18 years old, with primary sporadic DTF and with CTNNB1 mutations available, were eligible. The primary study endpoint was treatment-free survival (TFS). Secondary endpoints included the incidence of RECIST progression, spontaneous RECIST regression and regression post-RECIST progression. Results: Two hundred and eighty-two patients (n = 282) with a median follow-up of 53 months (IQR, 39-63) were included. Three-year and five-year TFS were 67% and 66%, crude cumulative incidences (CCI) of RECIST progression were 33% and 34%, of RECIST regression 26% and 34% and of regression post-RECIST progression 33% and 38%. In multivariable analysis, larger tumour size, mutation type, tumor locations were associated to lower TFS. The specific mutation (S45F), larger tumor size, and extremity and trunk location were all associated with a lower probability of spontaneous RECIST regression. Conclusions: This study confirms that spontaneous regression occurs in a significant proportion of patients and that two-thirds are treatment-free at 5 years. Initial tumor size, CTNNB1 mutation, and location should be factored into the initial decision-making process.

中文翻译：

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腹外硬纤维瘤病患者的主动监测：3 项前瞻性观察研究的汇总分析


目的：三项关于腹外硬纤维瘤病 （DTF） 患者主动监测 （AS） 的前瞻性观察性研究 （Italy、Netherlands、France） 支持 AS 作为一线方法。确定 AS 失败的预后因素将有助于确定策略。本研究的目的是在更大的系列中调查临床和分子变量的预后影响。实验设计：汇总了截至 2024 年 1 月 31 日的三项研究的数据，其中患者随访了 ≥3 年。≥18 岁、原发性散发性 DTF 且具有 CTNNB1 突变的患者符合条件。主要研究终点是无治疗生存期 （TFS）。次要终点包括 RECIST 进展的发生率、自发性 RECIST 回归和 RECIST 后进展的回归。结果： 纳入 282 例患者 （n = 282），中位随访 53 个月 （IQR，39-63）。3 年和 5 年 TFS 分别为 67% 和 66%，RECIST 进展的粗累积发生率 （CCI） 分别为 33% 和 34%，RECIST 回归 26% 和 34%，RECIST 后进展的回归 33% 和 38%。在多变量分析中，较大的肿瘤大小、突变类型、肿瘤位置与较低的 TFS 相关。特异性突变 （S45F） 、较大的肿瘤大小以及肢体和躯干位置都与自发性 RECIST 回归的概率较低相关。结论： 本研究证实，自发消退发生在很大一部分患者中，并且三分之二的患者在 5 年时未接受治疗。初始肿瘤大小、CTNNB1 突变和位置应在初始决策过程中考虑。