Sorafenib is currently one of the recommended treatments for symptomatic patients with desmoid-type fibromatosis (DTF). In this study, we aim to assess the clinical efficacy and tolerability of sorafenib in DTF patients.
Patients aged>18 years with a histological diagnosis of DTF and who have received sorafenib were enroled in this prospective observational study. Demographic data, clinical profile, the initial dose of sorafenib, treatment-related toxicities, dose modifications, and responses were recorded. The primary objective was to assess the objective response rate (ORR). The secondary objectives were to evaluate progression-free survival (PFS), tolerability, and adverse effects of sorafenib. Response assessment was based on response evaluation criteria in solid tumours 1.1 criteria. Adverse effects were graded according to National Cancer Institute Common Terminology Criteria for Adverse Events version 5.0 criteria. Time to event was calculated by Kaplan-Meier analysis, and survival was compared by log-rank test. Univariate and multivariable cox regression analysis were used to find independent predictors of relapse.
A total of 104 patients were enroled in the study. The median age of the study population was 32 (range, 18-81) years, and 66.35% of patients were females. On response assessment, ORR was 46.1% and stable disease was observed in 31.7% patients. ORR was higher in the appendicular site (51.7%) compared to the abdominal site (27.2%). PFS at 1 and 2 years was 86.6% (79.6-92.7%) and 73.7% (62.4-82.8%), respectively. Two-thirds (66.6%) of patients had already received some form of treatment. At the time of analysis, 70 (67.3%) patients were continuing sorafenib. Only 4.8% stopped sorafenib due to progression, 10.5% due to intolerable adverse effects, and 17.3% due to other reasons. The common treatment-related toxicities were hand-foot skin reaction (HFSR) (89.4%), fatigue (79.8%), alopecia (70.1%), and diarrhoea (48.0%). In the patients with a starting dose of ≥400 mg (48.0% of patients), discontinuation was necessitated in 12% of patients, and further dose reduction was required in 58%, while only about 13% required dose reduction or discontinuation at a starting dose of 200 mg (51.9% of patients). Responses were not compromised due to lower starting doses.
Sorafenib has good activity in DTF, but it is associated with significant toxicity. The adverse effect profile is distinct in Indian patients with higher HFSR and alopecia. Due to the high rate of dose reduction/discontinuation with a starting dose of 400 mg, a starting dose of 200 mg may be recommended in Indian patients.

We present an extremely rare case of deep angiomyxoma (DAM) in the thigh that was misdiagnosed as desmoid-type fibromatosis. A 40-year-old Japanese woman presented with a mass on the left thigh. The histological diagnosis by needle biopsy was desmoid-type fibromatosis; the tumor grew slowly and was resected 4 years later. The histological diagnosis from the resected tumor was DAM. As of 16 months post-surgery, the patient has not noticed any local recurrence. Although DAM in a lower extremity is extremely rare, clinicians must be aware of its possible occurrence in areas relatively close to the pelvis.

OBJECTIVE: Desmoid-type fibromatosis (DF) is clonal fibroblastic proliferation that arises in the deep soft tissues, tends to reoccur, and is locally invasive. Desmoid-type fibromatosis of paranasal sinuses with intracranial extension is a rare condition that is even rarer in a small child. We aim to share with the reader our literature review, decision-making, and endoscopic endonasal operation procedure that combined gained us favorable results against this benign tumor with unpredictable natural history and disease course.
METHODS: We describe the decision-making process in the management of a 3-year-old boy with a history of sudden vision loss and vomiting. MR showed an expansive well-delineated homogeneous tumor in the sphenoid sinus with intracranial extension and optic nerves compression. The diagnosis of a sporadic form of desmoid-type fibromatosis was made using genetic testing of tumor tissue. A total gross removal was carried out with endoscopic endonasal microsurgical approach. At a 3-month follow-up, the patient is without any signs of recurrance.
CONCLUSIONS: The treatment of children with desmoid-type fibromatosis requires a multidisciplinary approach by clinicians experienced with the management of pediatric cancer. While the desmoid-type fibromatosis is a benign, locally invasive tumor, observation should be the first step in the management. In case of life-threatening or symptomatic cases, operations that preserve function and structure should be the first choice for this benign tumor with unpredictable natural history and disease course.

Desmoid-type fibromatosis (DTF) is a very rare variant of papillary thyroid carcinoma (PTC). It is essentially a dual tumor with a component of classical PTC with malignant epithelial proliferation (BRAF-mutated) and another component of mesenchymal proliferation (CTNNB1-mutated). We conducted a literature review on PTC-DTF. In total, 31 articles were identified, that together reported on 54 patients. The mean age was 47 years, with a 2.2:1 female predominance. No ultrasound features were found to be helpful in differentiating PTC-DTF from other PTC variants. Of the 43 cases that reported histological details, 60% had locally infiltrative disease (T3b or T4). Around 48% had cervical lymph node metastases, but none had distant metastases. While PTC-DTF may be locally more aggressive than classic PTC, its overall behavior is similar and can include extrathyroidal extension and lymph node metastases, which may contain a stromal component and show extranodal invasion. The mainstay of treatment for PTC-DTF is surgery, and the DTF component is not expected to be sensitive to radioactive iodine. External radiotherapy, non-steroidal anti-inflammatory drugs, tyrosine kinase inhibitors and chemotherapy have also been used in selected cases. Due to the rarity of these tumors and the lack of specific treatment guidelines, management should be discussed in a multidisciplinary team.

BACKGROUND: The mainstay of the treatment for desmoid-type fibromatoses has been shifting from surgery to drug treatment, making accurate prediction of the efficacy of drug treatment of extreme importance. On the other hand, desmoid-type fibromatoses arise everywhere in the body. The purpose of this systematic review was to address the clinical question of whether tumour location has an impact on the efficacy of drug treatment.
METHODS: A literature search from January 1990 to August 2017 was conducted. Four reviewers independently assessed and screened the literature for eligibility and determined the final articles. They rated each report according to the Grading of Recommendations Development and Evaluation approach. Based on the quality of \'Body of Evidence\', our clinical guideline committee developed a recommendation for the clinical question.
RESULTS: In total, 128 articles were extracted. After the screenings, 5 were chosen for the final evaluation. The drugs used in these articles were one each of toremifene, sorafenib, and methotrexate and vinblastine and of meloxicam. There were no randomized controlled trials, and two prospective and three retrospective case series were included. Therapeutic effects were observed slightly more markedly in extremity using meloxicam or methotrexate and vinblastine. In contrast, the efficacy of toremifene was slightly higher in non-extremity. However, the evidence level of all of the reports was judged to be low.
CONCLUSIONS: Considering the low evidence level, we concluded that the site-specific therapeutic effects of drugs could not be confirmed in desmoid-type fibromatoses.

BACKGROUND: An accurate diagnosis is crucial to determine the treatment modality for desmoid-type fibromatosis, although the histopathological diagnosis is occasionally difficult to make. Many desmoid-type fibromatosis have been reported to have hotspot mutation of β-catenin gene (CTNNB1). In the present study, we performed a systematic review to verify the usefulness of CTNNB1 mutation analysis in the diagnosis of desmoid-type fibromatosis.
METHODS: A literature search from January 1990 to August 2017 was conducted. Three reviewers independently assessed and screened the literature for eligibility and determined the final articles to be evaluated. Data regarding the sensitivity, specificity, accuracy and usefulness of CTNNB1 mutation analysis in the diagnosis of desmoid-type fibromatosis were recorded. We rated each report according to the Grading of Recommendations Development and Evaluation approach.
RESULTS: The search yielded 90 studies, seven of which were included after the first and second screenings. The positive rate of CTNNB1 mutation in desmoid-type fibromatosis was 86.8%, but the cohort of six of the seven reports was already diagnosed histopathologically as desmoid-type fibromatosis. Therefore, the usefulness of CTNNB1 mutation analysis in a cohort that is difficult to diagnose histopathologically is not clear in this review. Nevertheless, CTNNB1 mutation showed very high specificity in desmoid-type fibromatosis, indicating the usefulness of CTNNB1 mutation analysis in its diagnosis in combination with histological examination.
CONCLUSIONS: Because the lack of data precludes any useful comparison with histological diagnosis, the evidence level is low. However, considering its specificity, CTNNB1 mutation analysis may be useful in cases in which the histopathological diagnosis is difficult.

Desmoid-type fibromatosis (DF) is a rare, locally infiltrative, and fibroblastic proliferative disease. DF usually arises from abdominal fascial tissue, but in rare cases, it can occur in extra-abdominal areas. A 73-year-old Japanese male complained of a painless, left anterior neck mass of 3-month duration. Computed tomography revealed the mass measured 9 × 7 × 6 cm and extended to the anterior mediastinum, with invasion of the left clavicle. En bloc resection of the tumor with the left sternoclavicular joint and the medial portion of the left clavicle was performed by cervico-thoracic approach with L-shaped partial sternotomy. Histopathologic examination showed fascicular growth of spindle-shaped cells separated by abundant collagen. Immunohistologic examination revealed nuclear staining of β-catenin and cytoplasmic staining of vimentin. Genetic analysis of 160 cancer-related genes by next-generation sequencing (NGS) demonstrated only a missense mutation in the CTNNB1 gene (c.133T>C, p.S45P). DF extending from the neck to the anterior mediastinum is rare. We report the complete resection of a large-sized DF with the clavicular invasion. A low-frequency CTNNB1 mutation of DF was identified. Genetic analysis with NGS was beneficial for the diagnosis.

OBJECTIVE: The purpose of this systematic review is to assess and compare the efficacy of surgical treatment for patients with asymptomatic extra-peritoneal desmoid-type fibromatosis to the wait-and-see policy by evaluating (1) the exacerbation rate (exacerbation; recurrence after surgery or progressive disease following non-surgical treatment) and (2) treatment-associated complications in extra-peritoneal desmoid-type fibromatosis.
METHODS: We evaluated documents published between 1 January 1990 and 31 August 2017. The risk of bias in the selected literature was analyzed using the Cochrane Collaboration Risk of Bias Tool. Quality of evidence was evaluated using Grading of Recommendation, Assessment, Development and Evaluation approach.
RESULTS: One prospective cohort study, four case-control studies and five case series studies were identified. Meta-analysis was performed to evaluate the exacerbation rate after treatment on one prospective cohort study and four case-control studies. In comparing surgical and non-surgical treatments, the exacerbation rate was significantly higher in the surgical treatment group (odds ratio: 1.32, 95% confidence interval 1.01-1.73, P = 0.05). However, in the case series study, the recurrence rate was 23.4% for the surgical treatment group, while the progressive disease rate was 28.1% for the non-surgical treatment group. The postoperative complication rates associated with surgical treatment in the two studies were 20.8 and 17.2%, respectively.
CONCLUSIONS: When considering the exacerbation rate, non-surgical treatment might be appropriate for asymptomatic patients with extra-peritoneal desmoid-type fibromatosis. However, if patients with tumor-related symptoms opt for surgery, including those who face difficulties due to the presence of tumors, it is important to fully explain to them the possibility that the recurrence rate and treatment-associated functional failures may increase depending on the site of occurrence.

OBJECTIVE: The treatment modality for desmoid-type fibromatosis has shifted from surgery to conservative treatment. This systematic review aims to evaluate the efficacy of low-dose chemotherapy with methotrexate and vinblastine for patients with extra-abdominal desmoid-type fibromatosis.
METHODS: We searched the pertinent literature from January 1990 to August 2017. Two reviewers evaluated and screened the literature independently for eligibility and extracted data. We evaluated the quality of body of evidence and made a recommendation according to the Grading of Recommendations Development and Evaluation methodology.
RESULTS: The search yielded 40 studies, 9 of which were included after the first and second screenings. There were three prospective case series but no randomized controlled trials among the nine studies. There was no case-control report (vs. no treatment). According to Response Evaluation Criteria in Solid Tumors criteria, the mean response rate (complete remission or partial response) was 36% (11-57%). Including stable disease, namely, clinical benefit was consistently as high as 85% (69-100%). Mean adverse event rate of G3 or G4 according to CTCAE was 31%. One study reported improvement of pain (87.5%) because of this chemotherapy.
CONCLUSIONS: The efficacy of this chemotherapy was convincing. However, the overall evidence was weak, and this chemotherapy is not covered by insurance in Japan; we only weakly recommend low-dose chemotherapy with methotrexate and vinblastine in patients with extra-abdominal desmoid-type fibromatosis.

Desmoid-type fibromatosis (DTF) is a rare, soft tissue tumor of mesenchymal origin which is characterized by local infiltrative growth behavior. Besides \"wait and see,\" surgery and radiotherapy, several systemic treatments are available for symptomatic patients. Recently, targeted therapies are being explored in DTF. Unfortunately, effective treatment is still hampered by the limited knowledge of the molecular mechanisms that prompt DTF tumorigenesis. Many studies focus on Wnt/β-catenin signaling, since the vast majority of DTF tumors harbor a mutation in the CTNNB1 gene or the APC gene. The established role of the Wnt/β-catenin pathway in DTF forms an attractive therapeutic target, however, drugs targeting this pathway are still in an experimental stage and not yet available in the clinic. Only few studies address other signaling pathways which can drive uncontrolled growth in DTF such as: JAK/STAT, Notch, PI3 kinase/AKT, mTOR, Hedgehog, and the estrogen growth regulatory pathways. Evidence for involvement of these pathways in DTF tumorigenesis is limited and predominantly based on the expression levels of key pathway genes, or on observed clinical responses after targeted treatment. No clear driver role for these pathways in DTF has been identified, and a rationale for clinical studies is often lacking. In this review, we highlight common signaling pathways active in DTF and provide an up-to-date overview of their therapeutic potential.