Evidence of hydroxyurea activity in children with pretreated desmoid-type fibromatosis: A new option in the armamentarium of systemic therapies

Oral vinorelbine in young patients with desmoid-type fibromatosis

BACKGROUND

Desmoid-type fibromatosis are rare intermediate tumors in children and adolescents. Owing to local aggressiveness and relapse, systemic treatment for symptomatic advanced or progressive forms is recommended. Following promising results in adult patients, oral vinorelbine is investigated in young patients.

METHODS

A retrospective review of young patients (<25 years old) with advanced or progressive desmoid type fibromatosis treated with oral vinorelbine in eight large centers of the Société Française des Cancers de l'Enfant was performed. In addition to tumor assessment according to RECIST 1.1, pre-treatment and during-treatment imagery were reviewed centrally to assess tumor volume and estimate fibrosis score through the change in percentage in hypoT2 signal intensity.

RESULTS

From 2005 to 2020, 24 patients (median age 13.9 years [range, 1.0-23.0]) received oral vinorelbine. Median number of prior systemic lines of treatment was 1 (range, 0-2), mainly based on intravenous low dose methotrexate and vinblastine. Before vinorelbine initiation, all patients had a progressive disease: radiological for 19, radiological and clinical (pain) for three and only clinical for two. Oral vinorelbine was delivered for a median duration of 12 months (range, 1-42). The toxicity profile was favorable, with no grade 3-4 event. Overall response estimated on 23 evaluable patients according to RECIST 1.1 criteria was three partial responses (13%), 18 stabilization (78%) and two progressive disease (9%). Overall progression-free survival was 89.3% (95% confidential intervals 75.2-100) at 24 months. Four stable tumors according to standard RECIST criteria displayed a partial response with > 65% tumor volume reduction. Among 21 informative patients, the estimated fibrosis score decreased for 15 patients, was stable for four patients and increased for two patients.

CONCLUSION

Oral vinorelbine seems to be effective to control advanced or progressive desmoid type fibromatosis in young patients, with a well-tolerated profile. These results support testing this drug as first-line alone or in combination to improve response rate while preserving quality of life.

Clinical outcomes of medical treatments for progressive desmoid tumors following active surveillance: a systematic review

Approximately 80% of desmoid tumors (DTs) show spontaneous regression or disease stabilization during first-line active surveillance. Medical treatment can be considered in cases of disease progression. This systematic review aimed to evaluate the effectiveness and toxicity of each medical treatment by reviewing only the studies that included progressive disease as the inclusion criterion. We searched the EMBASE, PubMed, and CENTRAL databases to identify published studies for progressive DTs. The disease control rates of the medical treatments, such as low-dose chemotherapy with methotrexate plus vinblastine or vinorelbine, imatinib, sorafenib, pazopanib, nilotinib, anlotinib, doxorubicin-based agents, liposomal doxorubicin, hydroxyurea, and oral vinorelbine for progressive DTs were 71-100%, 78-92%, 67-96%, 84%, 88%, 86%, 89-100%, 90-100%, 75%, and 64%, respectively. Low-dose chemotherapy, sorafenib, pazopanib, nilotinib, anlotinib, and liposomal doxorubicin had similar toxicities. Sorafenib and pazopanib were less toxic than imatinib. Doxorubicin-based chemotherapy was associated with the highest toxicity. Hydroxyurea and oral vinorelbine exhibited the lowest toxicity. Stepwise therapy escalation from an initial, less toxic treatment to more toxic agents is recommended for progressive DTs. Sorafenib and pazopanib had limited on-treatment side effects but had the possibility to induce long-term treatment-related side effects. In contrast, low-dose chemotherapy has some on-treatment side effects and is known to have very low long-term toxicity. Thus, for progressive DTs following active surveillance, low-dose chemotherapy is recommended in young patients as long-term side effects are minor, whereas therapies such as sorafenib and pazopanib is recommended for older patients as early side effects are minor.

The Role of Pharmacotherapeutic Agents in Children with Desmoid Tumors

Desmoid tumors (DT) are rare fibroblastic, soft-tissue tumors that do not metastasize but can aggressively infiltrate tissues causing significant chronic discomfort and/or functional impairment. In the pediatric population, the incidence of DT is greatest during infancy and adolescence but can occur at any age. Dysregulated β-catenin, most commonly resulting from mutations in either CTNNB1 or germline APC (adenomatous polyposis coli) drives DT. Most cases are sporadic but some are associated with predisposition syndromes such as familial adenomatous polyposis (FAP). Historically, treatment has been surgery. However, the recurrence rate after surgery can be high. Various systemic cytotoxic chemotherapy regimens used in other soft-tissue sarcomas have been applied to DT with differing results. Given the chronic and rarely life-threatening nature of this disease and the potential short- and long-term toxicity of these regimens, especially in children, alternative non-cytotoxic interventions have been investigated. Molecularly targeted agents such as tyrosine kinase and gamma secretase inhibitors have shown activity against DT. Innovative local control therapies are being employed as alternatives to surgery and radiation. Periods of prolonged stability and spontaneous regression in the absence of therapy in some patients has prompted wider adoption of an upfront active surveillance approach in the appropriate setting. This review will briefly summarize the epidemiology, pathophysiology, and clinical presentation of DT in children, then focus on historical, current, and future pharmacotherapeutic management and finally, propose areas for future study.

Desmoid tumors located in the abdomen or associated with adenomatous polyposis: French intergroup clinical practice guidelines for diagnosis, treatment, and follow-up (SNFGE, FFCD, GERCOR, UNICANCER, SFCD, SFED, SFRO, ACHBT, SFR)

INTRODUCTION

Desmoid tumor (DT) of the abdomen is a challenging and rare disease. The level of evidence available to document their treatment is relatively low, however, recent publications of prospective studies have allowed to precise their management.

METHODS

This document is a summary of the French intergroup guidelines realized by all French medical and surgical societies involved in the management of DT located in the abdomen or associated with adenomatous polyposis. Recommendations are graded in four categories (A, B, C and D), according to the level of evidence found in the literature until January 2021.

RESULTS

When the diagnosis of DT is suspected a percutaneous biopsy should be performed when possible. A molecular analysis looking for pathogenic mutations of the CTNNB1 and APC genes should be systematically performed. When a somatic pathogenic variant of the APC gene is present, an intestinal polyposis should be searched. Due to a high rate of spontaneous regression, non-complicated DT should first benefit from an active surveillance with MRI within 2 months after diagnosis to assess the dynamic of tumor growth. The treatment decision must be discussed in an expert center, favoring the less toxic treatments which can include broad spectrum tyrosine kinase inhibitor or conventional chemotherapy (methotrexate-vinblastine). Surgery, outside the context of emergency, should only be considered for favorable location in an expert center.

CONCLUSION

French guidelines for DT management were elaborated to help offering the best personalized therapeutic strategy in daily clinical practice as the DT therapeutic landscape is complexifying. Each individual case must be discussed within a multidisciplinary expert team.

Desmoid-type fibromatosis: toward a holistic management

PURPOSE OF REVIEW

Desmoid-type fibromatosis, a rare locally aggressive fibroblastic proliferation, is a treatment challenge. This review aimed to explore recent data about the management of desmoid-type fibromatosis.

RECENT FINDINGS

New data underline the role of kinases and ɣ-secretase in stimulating cell proliferation and invasiveness in desmoid-type fibromatosis. This explains the proven activity of multikinase inhibitors (sorafenib or pazopanib) in the management of desmoid-type fibromatosis or the emerging role of a ɣ-secretase inhibitor. An international guideline for management was recently published, and this guideline take into account patient point of view. Lastly, recent studies highlight the multidimensional burden of desmoid-type fibromatosis, particularly health-related quality of life (HRQoL).

SUMMARY

Active surveillance with planned MRI is the first-line management in desmoid-type fibromatosis. A site-specific and stepwise approach should be considered for progressive desmoid-type fibromatosis. Further, a risk-benefit analysis that considers the side effects and long-term sequelae should be conducted before deciding to start any treatment. A less aggressive approach should be considered. Multikinase inhibitors are effective, but their tolerability and side effects should be discussed with the patients. The symptoms and HRQoL should be integrated in decision-making. Desmoid-type fibromatosis patients should be offered support to address their needs supportive care.

Rationale for the use of tyrosine kinase inhibitors in the treatment of paediatric desmoid-type fibromatosis

In children with desmoid-type fibromatosis (DTF) in whom disease progression occurs after an initial watch-and-wait strategy, prolonged low-dose chemotherapy using vinblastine and methotrexate (VBL-MTX) is currently the standard of care. These conventional drugs have been prospectively evaluated but their efficacy and safety profiles are limited, and alternative therapeutic options are therefore essential. Based on the results of clinical trials, the use of tyrosine kinase inhibitors (TKIs) in the treatment of DTF is currently considered only in adult patients. TKIs such as imatinib show superior therapeutic efficacy to VBL-MTX and tolerable short-term side effects for the treatment of adult DFT, supporting the concept of the use of TKIs for the treatment of paediatric DFT. Moreover, new-generation TKIs, such as pazopanib and sorafenib, have shown improved therapeutic efficacy compared to imatinib in adult non-comparative studies. A tolerable safety profile of TKI therapy in children with disease entities other than DTF, such as leukaemia, has been reported. However, the efficacy and, in particular, the long-term safety of TKIs, including childhood-specific aspects such as growth and fertility, for the treatment of children with DTF should be investigated prospectively, as DFT therapy requires long-term drug exposure.

Desmoid tumors of the head and neck in the pediatric population: Has anything changed?

INTRODUCTION

Pediatric head and neck desmoid tumors are rare neoplasms that can cause significant morbidity due to infiltration of vital anatomic structures. The goal of this study is to review presentation, evaluation, and management of these tumors.

METHODS

Retrospective study of children with head and neck desmoid tumors treated from 1999 to 2018 and literature review.

RESULTS

11 patients (5 boys, 6 girls) were included. Presentation included firm neck mass (n = 8), trismus (n = 2) and tongue lesion (n = 1). All patients had preoperative imaging with CT (n = 2), MRI (n = 1) or both (n = 8). Five patients underwent needle biopsy, five had open biopsy and one was diagnosed on pathology from primary excision. Seven patients were treated by primary surgical resection, with positive surgical margins in six cases due to proximity to vital neurovascular structures. None needed chemotherapy, had disease recurrence or progression. Three patients with unresectable disease were treated with chemotherapy. One patient was monitored with imaging without any treatment and did not have disease progression. Follow-up ranged from 6 months to 6 years (median 21 months). Ten patients (7 surgical, 2 chemotherapy, 1 observation) were either disease-free or had stable disease at last follow-up.

CONCLUSION

Pediatric head and neck desmoid tumors, though rare and histologically benign, are locally infiltrative and aggressive. When feasible, surgical treatment results in good disease control despite positive margins. A balance between achieving negative margins and minimizing functional deficits should be considered. Chemotherapy can be successfully utilized in patients where surgery entails a high risk of morbidity and mortality.

Safety and efficacy of gamma-secretase inhibitor nirogacestat (PF-03084014) in desmoid tumor: Report of four pediatric/young adult cases

Systemic therapy for pediatric desmoid tumors has been challenged by a lack of high-quality clinical evidence and potential adverse effects. The gamma-secretase inhibitor nirogacestat has shown promising efficacy in adults. We report four cases of pediatric and young adult desmoid tumor patients (three with familial adenomatous polyposis [FAP] syndrome) who received nirogacestat on compassionate use. After a median of 13.5 months (range 6-18), three had durable benefit: a complete response (Case 1); a partial response (Case 2); stable disease (Case 3). The fourth had disease progression after a partial response. No patient experienced grade 3 or 4 adverse events.

The management of desmoid tumours: A joint global consensus-based guideline approach for adult and paediatric patients

Desmoid tumor (DT; other synonymously used terms: Desmoid-type fibromatosis, aggressive fibromatosis) is a rare and locally aggressive monoclonal, fibroblastic proliferation characterised by a variable and often unpredictable clinical course. Previously surgery was the standard primary treatment modality; however, in recent years a paradigm shift towards a more conservative management has been introduced and an effort to harmonise the strategy amongst clinicians has been made. We present herein an evidence-based, joint global consensus guideline approach to the management of this disease focussing on: molecular genetics, indications for an active treatment, and available systemic therapeutic options. This paper follows a one-day consensus meeting held in Milan, Italy, in June 2018 under the auspices of the European Reference Network for rare solid adult cancers, EURACAN, the European Organisation for Research and Treatment of Cancer (EORTC) Soft Tissue and Bone Sarcoma Group (STBSG) as well as Sarcoma Patients EuroNet (SPAEN) and The Desmoid tumour Research Foundation (DTRF). The meeting brought together over 50 adult and pediatric sarcoma experts from different disciplines, patients and patient advocates from Europe, North America and Japan.

[Systemic treatment for management of aggressive fibromatosis in both adult and children: Level of evidence and unsolved questions]

We summarize here available data about systemic treatments of desmoids tumors, as well in adult patients as pediatric patients. Until 2018, the level of evidence associated with these treatments (NSAI, hormonal therapies, tyrosine kinase inhibitors, chemotherapy) was very low, based on retrospective studies or non-randomized phase 2 trials with limited number of cases. In 2018-2019, 2 large randomized trials have been published, including one large superiority phase 3 trial comparing sorafenib to placebo. This trial clearly demonstrates the clinical benefit of sorafenib over placebo (level of evidence IA). To conclude, wait-and-see policy must be the first-line approach, systemic treatment is indicated in case of disease progression. Randomized trials are feasible in this exceptional disease.