Developing knowledge, attitude and practice questionnaire in desmoid tumours (KAPID study): applying e-Delphi to rare diseases.

Background: Rare diseases are associated with unique challenges encountered in diagnosis, treatment and conduct of clinical research. Desmoid tumour (DT) is one such ultra-rare malignancy about which awareness among medical professionals remains limited. We developed a questionnaire to assess knowledge, attitude and practice (KAP) among medical professionals on DT. Methods: E-Delphi method was used for the assessment of KAP for DT amongst clinical experts (experience of >/= 3 years in DT). 22 open-ended statements were developed by the core research group using current consensus guidelines. In round 1, experts provided subjective feedback which was incorporated into a 35-item questionnaire. Round 2 entailed experts giving feedback as a 5-point Likert scale classified into agreement (median score >/=4), neutral (median score 3) and disagreement (median score <3). Feedback from Round 2 was incorporated and questions with neutral consensus were modified. Questions in Round 3 achieved consensus if >/= 75% participants agreed. Results: 11 (64.7%) of 17 contacted experts responded in Round 1 including 6 (54.4%) who gave additional inputs and 5 (45.6%) who agreed to all statements. In round 2, 8 out of 11 experts responded to the 35-item questionnaire on knowledge (n = 16), attitude (n = 8) and practice (n = 11). 32 questions obtained agreement and 3 (8.5%) had neutral consensus. These were modified for round 3, in which consensus on 2 (66.6%) was attained. The final questionnaire comprises 34 items with 15, 8 and 11 questions on in the sections of knowledge, attitude and practice (KAP), respectively.

Capturing Patient Voice to Improve Outcomes That Matter to Patients with Desmoid Tumor.

Desmoid tumors (DT) are rare, intermediate-grade sarcomas characterized by locally aggressive growths that commonly occur intra-abdominally, in the abdominal wall, or in the extremities. Desmoid tumors are 2-3-fold more common in females than males, with most patients aged <40 years at diagnosis. Clinical course of DT is highly variable but rarely fatal, with median overall survival >80% at 20 years. However, patient morbidity and DT symptom burden can be high. DT significantly reduce patient quality of life, imposing substantial physical, emotional, and social burdens. Pain, fatigue, and insomnia are common symptoms; disfigurement, mobility restrictions, and, rarely, the need for amputation may also result. Despite its limited impact on survival, patients with DT may have anxiety and depression levels commensurate with those associated with malignant sarcomas. Thus, DT impose an array of significant, long-term morbidities on a young patient population. In order to evaluate the impact of these morbidities, patient-reported outcome (PRO) tools are used, which assess outcomes of importance to patients that extend beyond traditional oncology endpoints. General or oncology-related PROs can be used; although currently, the only DT-specific, validated PRO measure is the GOunder/Desmoid Tumor Research Foundation DEsmoid Symptom/Impact Scale (GODDESS©), consisting of an 11-item DT Symptom Scale (DTSS) and a 17-item DT Impact Scale (DTIS). DTSS and DTIS were secondary endpoints in DeFi, a randomized phase 3 trial of nirogacestat; blinded, pooled data from DeFi were used to validate GODDESS reliability and responsiveness as a PRO measure in DT. Another DT-specific PRO measure, the Desmoid-Type Fibromatosis Quality of Life (DTF-QoL) questionnaire, has been developed but not validated. As novel DT therapies continue to be developed, incorporating DT-specific PRO measures into clinical trials will be key to capturing patient voice, improving outcomes of importance to this unique patient population, and assisting patients and providers in selecting optimal treatment.

Overcoming Clinical Resistance to EZH2 Inhibition Using Rational Epigenetic Combination Therapy.

Epigenetic dependencies have become evident in many cancers. On the basis of antagonism between BAF/SWI-SNF and PRC2 in SMARCB1-deficient sarcomas, we recently completed the clinical trial of the EZH2 inhibitor tazemetostat. However, the principles of tumor response to epigenetic therapy in general, and tazemetostat in particular, remain unknown. Using functional genomics and diverse experimental models, we define molecular mechanisms of tazemetostat resistance in SMARCB1-deficient tumors. We found distinct acquired mutations that converge on the RB1/E2F axis and decouple EZH2-dependent differentiation and cell-cycle control. This allows tumor cells to escape tazemetostat-induced G1 arrest, suggests a general mechanism for effective therapy, and provides prospective biomarkers for therapy stratification, including PRICKLE1. On the basis of this, we develop a combination strategy to circumvent tazemetostat resistance using bypass targeting of AURKB. This offers a paradigm for rational epigenetic combination therapy suitable for translation to clinical trials for epithelioid sarcomas, rhabdoid tumors, and other epigenetically dysregulated cancers. SIGNIFICANCE: Genomic studies of patient epithelioid sarcomas and rhabdoid tumors identify mutations converging on a common pathway for response to EZH2 inhibition. Resistance mutations decouple drug-induced differentiation from cell-cycle control. We identify an epigenetic combination strategy to overcome resistance and improve durability of response, supporting its investigation in clinical trials. See related commentary by Paolini and Souroullas, p. 903. This article is featured in Selected Articles from This Issue, p. 897.

Epigenetic targeting of PGBD5-dependent DNA damage in SMARCB1-deficient sarcomas.

Despite the potential of targeted epigenetic therapies, most cancers do not respond to current epigenetic drugs. The Polycomb repressive complex EZH2 inhibitor tazemetostat was recently approved for the treatment of SMARCB1-deficient epithelioid sarcomas, based on the functional antagonism between PRC2 and loss of SMARCB1. Through the analysis of tazemetostat-treated patient tumors, we recently defined key principles of their response and resistance to EZH2 epigenetic therapy. Here, using transcriptomic inference from SMARCB1-deficient tumor cells, we nominate the DNA damage repair kinase ATR as a target for rational combination EZH2 epigenetic therapy. We show that EZH2 inhibition promotes DNA damage in epithelioid and rhabdoid tumor cells, at least in part via its induction of the transposase-derived PGBD5. We leverage this collateral synthetic lethal dependency to target PGBD5-dependent DNA damage by inhibition of ATR but not CHK1 using elimusertib. Consequently, combined EZH2 and ATR inhibition improves therapeutic responses in diverse patient-derived epithelioid and rhabdoid tumors in vivo. This advances a combination epigenetic therapy based on EZH2-PGBD5 synthetic lethal dependency suitable for immediate translation to clinical trials for patients.

Current Management of Desmoid Tumors: A Review.

Importance: Desmoid tumor (DT) is a rare and locally aggressive monoclonal, fibroblastic proliferation characterized by a variable and often unpredictable clinical course. Previously, surgery was the standard primary treatment modality; however, within the past decade, a paradigm shift toward less-invasive management has been introduced and an effort to harmonize the strategy among clinicians has been made. To update the 2020 global evidence-based consensus guideline on the management of patients with DT, the Desmoid Tumor Working Group convened a 1-day consensus meeting in Milan, Italy, on June 30, 2023, under the auspices of the European Reference Network on Rare Adult Solid Cancers and Sarcoma Patient Advocacy Global Network, the Desmoid Foundation Italy, and the Desmoid Tumor Research Foundation. The meeting brought together over 90 adult and pediatric sarcoma experts from different disciplines as well as patients and patient advocates from around the world. Observations: The 2023 update of the global evidence-based consensus guideline focused on the positioning of local therapies alongside surgery and radiotherapy in the treatment algorithm as well as the positioning of the newest class of medical agents, such as γ-secretase inhibitors. Literature searches of MEDLINE and Embase databases were performed for English-language randomized clinical trials (RCTs) of systemic therapies to obtain data to support the consensus recommendations. Of the 18 full-text articles retrieved, only 4 articles met the inclusion criteria. The 2023 consensus guideline is informed by a number of new aspects, including data for local ablative therapies such as cryotherapy; other indications for surgery; and the γ-secretase inhibitor nirogacestat, the first representative of the newest class of medical agents and first approved drug for DT. Management of DT is complex and should be carried out exclusively in designated DT referral centers equipped with a multidisciplinary tumor board. Selection of the appropriate strategy should consider DT-related symptoms, associated risks, tumor location, disease morbidities, available treatment options, and preferences of individual patients. Conclusions and Relevance: The therapeutic armamentarium of DT therapy is continually expanding. It is imperative to carefully select the management strategy for each patient with DT to optimize tumor control and enhance quality of life.