Desmoid tumor: from surgical extirpation to molecular dissection

Examining nirogacestat for adults with progressing desmoid tumors who require systemic treatment

INTRODUCTION

Desmoid tumor (DT) is a rare, locally aggressive, mesenchymal neoplasm that can arise at any site in the body. Medical therapies play a major role for DT's patients requiring treatment. A novel systemic approach has recently emerged with Nirogacestat, a γ-secretase inhibitor targeting the NOTCH signaling pathway.

AREAS COVERED

Nirogacestat is the first drug in its class to receive approval from the Food and Drug Administration (FDA) and is the first FDA-approved treatment specifically for DTs. We reviewed the data leading to its discovery, including its mechanism of action, pharmacological properties, clinical efficacy, and its positioning within the current treatment armamentarium for DTs.

EXPERT OPINION

High-quality evidence for systemic therapies in the management of DTs remains an unmet need. Nirogacestat now joins sorafenib as the only drugs with efficacy in DTs demonstrated by randomized phase 3 studies. Currently, there are no comparative trials of the available systemic therapies. Therefore, physicians should consider factors such as drug accessibility, cost, toxicity profile, comorbidities, and patient preferences when selecting treatment. Long-term efficacy and safety data will be essential for evaluating the duration of treatment response and monitoring late-onset side effects of Nirogacestat.

Real-word experience of pazopanib and sorafenib in patients with desmoid tumors: A CanSaRCC multi-center study

BACKGROUND

Sorafenib and pazopanib, two tyrosine kinase inhibitors (TKI), are widely used in patients with progressive symptomatic desmoid tumors (DT). Limited real-word data is available on long-term outcomes of patients who progressed on, stopped, or continued TKIs.

METHODS

Patients diagnosed with DTs and treated with sorafenib or pazopanib between 2011 and 2022 at 11 institutions were reviewed. Patient history, response to therapy and toxicity were recorded. Statistical analyses utilized Kaplan-Meier and log-rank tests.

RESULTS

142 patients with DT treated with sorafenib (n = 126, 88.7 %) or pazopanib (n = 16, 11.3 %) were analyzed. The median treatment duration was 10.8 months (range: 0.07- 73.9). The overall response rate and the disease control rate were 26.0 % and 95.1 %, respectively. The median tumor shrinkage was - 8.5 % (range -100.0 %- +72.5 %). Among responders, the median time to an objective response was 15.2 months (range: 1.1 to 33.1). The 1-year and 2-year progression-free survival rates were 82 % and 80 %. Dose reductions were necessary in 34 (23.9 %) patients. Grade 3 or higher adverse events were reported in 36 (25.4 %) patients. On the last follow-up, 55 (38.7 %) patients continued treatment. Treatment discontinuation (n = 85, 59.9 %) was mainly for toxicity (n = 35, 45.9 %) or radiological or clinical progression (n = 30, 35.3 %). For the entire cohort, 36 (25.4 %) patients required subsequent treatment. In the 32 responders, only 1 (3.1 %) patient required a subsequent treatment. In patients who discontinued TKI, 25 (44.6 %) with stable disease received subsequent treatment compared to 0 (0.0 %) of responders.

CONCLUSION

This retrospective study represents the largest cohort of DT patients treated with sorafenib or pazopanib to date. Discontinuation of treatment in responders is safe. The optimal treatment duration in patients with stable disease remains to be defined.

Iodine-125 brachytherapy for a desmoid tumor in the abdomen-thorax: A retrospective study

PURPOSE

To investigate the safety and efficacy of iodine-125 seed implantation in the treatment of abdomen-thorax desmoid tumors (DTs).

METHODS AND MATERIALS

Data from 14 DT patients who received brachytherapy with iodine-125 seeds were retrospectively collected from 2014 to 2020. The operation was completed using CT guidance and the treatment plan system (TPS). The number of lesions and the target dosimetry parameters were recorded. After brachytherapy, the lesions were evaluated using response evaluation criteria in solid tumors (RECIST).

RESULTS

Fourteen patients with 18 lesions were enrolled in this study; eleven lesions were in the thorax, seven were in the abdomen, and the lesion gross tumor volume (GTV) was 82.10 cc (interquartile range [IQR]: 40.37, 203.42 cc). The median number of seeds was 88 (IQR: 35, 158), and the median prescription dose was 120 Gy (IQR: 115, 120 Gy). The D90 was 123 ± 16.7 Gy, the V90 was 97% (IQR: 95.00, 97.25%), and the V200 was 27% (IQR: 14.50, 33.00%). The median follow-up time for each lesion was 34 (IQR: 23, 67) months, and the local response rate was 100%. Following brachytherapy, the overall survival was 52.3 ± 30.72 months. One year after brachytherapy, one patient experienced persistent worsening of a brachial plexus injury; another received a ureteral stent. No brachytherapy-related complications were observed in the remaining patients.

CONCLUSIONS

Iodine-125 brachytherapy is a novel treatment option for DT of the abdomen and thorax. Although it is a safe and effective treatment, the radiation dose of iodine-125 brachytherapy for DT-embedded organs at risk must be investigated further.

A Review of the Clinical Presentation, Outcomes, and Treatments of Patients Having Desmoid Tumors

Desmoid tumors (DTs) are deep fibroblastic neoplasms that arise from musculo-aponeurotic stromal elements. DTs may result in significant morbidity by infiltrating vital anatomic structures. Their mortality is often due to the local aggressiveness, most commonly when intra-abdominal in location. Some indolent DTs can be observed expectantly; infiltrative tumors require an aggressive and multidisciplinary approach and are offered conservative therapies such as nonsteroidal anti-inflammatory drugs or antiestrogens when surgery is not feasible. Comparably, chemotherapy is considered for those cases not amenable to surgery or radiation. Bowel resection and at times intestinal transplantation may be necessary. However, DTs may recur postsurgery making long-term management of these patients. Herein, we review the genetics, clinical presentations, outcomes, and treatments of DTs.

Targeted therapy in advanced desmoid tumors: Current perspectives

Background

Desmoid tumors/aggressive fibromatosis (DTs/AF) are cytological bland fibrous neoplasms originating from the musculoaponeurotic structures throughout the body. The exact cause still remains unknown, however, they may present sporadically or as a manifestation of a hereditary syndrome called familial adenomatous polyposis (FAP). Although they lack the capacity to establish metastases, DTs/AF may be devastated and occasionally fatal. As a result of the heterogeneity of DTs/AF, treatment needs to be individualized to improve local tumor control and maintain patients’ quality of life. Therefore, after a multidisciplinary approach, all treatment options should be discussed with patients. Where systemic chemotherapy has been shown to be unsuccessful with marked side effects in case of advanced DTs/AF, new therapeutic options are needed.

Methods

A Medline search was conducted and published articles in different studies from 2000 to the present were reviewed.

Conclusion

More research is needed to illustrate both the prognostic and predictive factors of the targeted therapy and the value of their combinations with or without other treatment modalities to get the best result for the treatment of advanced DTs/AF.

Long-Term Outcomes for Patients With Desmoid Fibromatosis Treated With Radiation Therapy: A 10-Year Update and Re-evaluation of the Role of Radiation Therapy for Younger Patients

PURPOSE

To update our experience with long-term outcomes in patients with desmoid fibromatosis treated with radiation therapy (RT) and to characterize factors associated with increased risk of local recurrence.

METHODS AND MATERIALS

We reviewed the records of 209 consecutive patients with desmoid fibromatosis treated with RT, either alone or as combined-modality therapy (CMT) with surgery, at our institution from 1965 to 2015.

RESULTS

Median follow-up time was 98 months (range, 1-509 months). The 5- and 10-year local control (LC) was 71% and 69%, respectively. Fifty-nine patients (28%) experienced a local recurrence at a median time of 23 months (interquartile range, 15-38 months). Among all patients, on multivariable analysis, adjusting for anatomic site, size, age, treatment era (>2005 vs ≤2005), treatment approach (RT alone vs CMT), and an interaction between age and treatment, we found only age ≤30 years (hazard ratio [HR], 2.94; P = .005; 95% confidence interval [CI], 1.38-6.27) and large tumor size >10 cm (HR, 2.51; P = .03; 95% CI, 1.09-5.78) to be correlated with poorer LC. Notably, for patients receiving RT alone, the 5-year LC was 43% for patients ≤30 years old versus 75% for >30 years old (P < .001). On multivariable analyses, for patients receiving RT alone, the only factor associated with inferior LC was age ≤30 years (HR, 2.87; P = .001; 95% CI, 1.51-5.47). The same was true for patients treated with CMT; age ≤30 years was the only factor associated with inferior LC (HR, 5.36; P = .01; 95% CI, 1.40-20.58).

CONCLUSIONS

Among all patients with desmoid fibromatosis, RT is an effective local therapy for tumor control. However, young patients ≤ 30 years have notably high rates of local recurrence regardless of treatment strategy, which requires further study. Treatment decisions should be risk-adapted by large referral centers with multidisciplinary expertise in desmoid management.

Clinical prognostic factors for pediatric extra-abdominal desmoid tumor: analyses of 66 patients at a single institution

Background and purpose

Pediatric desmoid tumor (PDT) is rare and has a high local recurrence rate. The purpose of the present study was to analyze clinical risk factors of local recurrence in PDT patients.

Materials and methods

We reviewed clinical data of 66 PDT patients from 2004 to 2015. All patients underwent macroscopically complete resection, and some recurrent tumors were prescribed radiotherapy. Factors such as sex, age at presentation, location, and proximity to nerves or vasculature were analyzed. The local recurrence rate and recurrence-free survival were analyzed with these factors.

Results

All patients in the present study were children and had extra-abdominal tumors. The median follow-up time was 6.6 years. Thirty-six (55%) patients had local recurrence. Age, sex, tumor site, tumor size, and proximity to nerves/vasculature had a significant impact on prognosis in univariate analysis. Radiotherapy decreased the local recurrence rate. In multivariate analysis, younger age, tumor location in buttocks, larger tumor, and proximity to important nerves/vasculature were independent risk factors for poor prognosis.

Conclusions

Favorable therapeutic strategies could be selected according to the preoperative prognostic risk factors. Radiotherapy should be considered for local recurrence of PDT.

Desmoid-Type Fibromatosis: Who, When, and How to Treat

OPINION STATEMENT

Desmoid-type fibromatosis is a sarcoma subtype that gathers some singular characteristics, making it a difficult challenge to face in clinical practice. Despite its excellent survival prognosis, these tumors may be unpredictable, ranging from an asymptomatic indolent course to persistent, local, and extended recurrences that significantly impair quality of life. Although surgery was initially considered the first elective treatment, collected published data during the past few years are now pointing to the "wait and see" approach as a reasonable initial strategy because many patients can live a long life with the disease without having symptoms. When symptoms appear or there is a risk of functional impairment, a wide spectrum of therapies (local and systemic) can be useful in improving symptoms and controlling the disease. Because of the low incidence of desmoid-type fibromatosis, there is scarce scientific evidence supporting any specific treatment. Nonetheless, if volumetric responses are needed, chemotherapy may be a reasonable early option. However, if long-term control of disease is desirable, hormonal therapy, NSAIDs, and TKIs are the likely treatments of choice. Recent new findings in the biologic development of these tumors, such as the role of Wnt/β-catenin dependent pathway, have shown that the prognostic information provided by specific CTNNB1 gene mutations and other genetic profiles can lead to better methods of selecting patients as candidates for other approaches. Based on recent research, the Notch pathway inhibition in DF is one of the most promising potential targets to explore. As an orphan disease, it is mandatory that as many patients as possible be included in clinical trials.

Borderline Sarcomas and Smooth Muscle Tumours of Uncertain Malignant Potential

Borderline sarcomas and smooth muscle tumours of uncertain malignant potential (STUMP) have an unpredictable clinical behaviour with frequent local recurrences and rarely, metastases. We review the current management of common subtypes of borderline sarcomas and STUMP.

Clinical Activity of the γ-Secretase Inhibitor PF-03084014 in Adults With Desmoid Tumors (Aggressive Fibromatosis)

Purpose Desmoid tumors (aggressive fibromatosis) arise from connective tissue cells or fibroblasts. In general, they are slow growing and do not metastasize; however, locally aggressive desmoid tumors can cause severe morbidity and loss of function. Disease recurrence after surgery and/or radiation and diagnosis of multifocal desmoid tumors highlight the need to develop effective systemic treatments for this disease. In this study, we evaluate objective response rate after therapy with the γ-secretase inhibitor PF-03084014 in patients with recurrent, refractory, progressive desmoid tumors. Patients and Methods Seventeen patients with desmoid tumors received PF-03084014 150 mg orally twice a day in 3-week cycles. Response to treatment was evaluated at cycle 1 and every six cycles, that is, 18 weeks, by RECIST (Response Evaluation Criteria in Solid Tumors) version 1.1. Patient-reported outcomes were measured at baseline and at every restaging visit by using the MD Anderson Symptoms Inventory. Archival tumor and blood samples were genotyped for somatic and germline mutations in APC and CTNNB1. Results Of 17 patients accrued to the study, 15 had mutations in APC or CTNNB1 genes. Sixteen patients (94%) were evaluable for response; five (29%) experienced a confirmed partial response and have been on study for more than 2 years. Another five patients with prolonged stable disease as their best response remain on study. Patient-reported outcomes confirmed clinician reporting that the investigational agent was well tolerated and, in subgroup analyses, participants who demonstrated partial response also experienced clinically meaningful and statistically significant improvements in symptom burden. Conclusion PF-03084014 was well tolerated and demonstrated promising clinical benefit in patients with refractory, progressive desmoid tumors who receive long-term treatment.

Functional and Aesthetic Thorax Reconstruction after Desmoid Tumor Resection

This study describes a case report of a 31-year-old patient who presented with a left thoracic tumor on costal cartilages 5 and 6 that was diagnosed as a desmoid tumor 3 years after receiving retropectoral breast implants for cosmetic reasons. The integral reconstruction of the thoracic wall, functional and aesthetic, was planned for a single surgical period. The defect secondary to the tumor resection, which left the pericardium and lung exposed, was closed using the pectoral muscle as a "pre-expanded" flap by the breast implant, and the breast aesthetic was treated bilaterally with new implants in the retromammary position. After 12 months, the patient remained free from tumor recurrence and had a satisfactory aesthetic result.

Efficacy of vinorelbine combined with low-dose methotrexate for treatment of inoperable desmoid tumor and prognostic factor analysis

Objective

To assess the efficacy of conservative chemotherapy for inoperable desmoid tumor (DT) and analyze the prognostic factors.

Methods

From November 2008 to April 2016, 71 patients of inoperable DT were treated with vinorelbine and low-dose methotrexate in the Department of Bone and Soft Tissue Tumors, Peking University Cancer Hospital & Institute, and enrolled in this retrospective study. The chemotherapy duration is one year. The efficacy of chemotherapy and the prognosis were observed.

Results

Of the 71 patients, 55% were female. Age of onset varied from 1 to 47 years, and the median age was 14 years. Only 11 (15.5%) cases suffered primary tumor. The distribution of the site of tumors was: 31 (43.7%) in the trunk, 36 (50.7%) in the limbs, and 4 (5.6%) in the peritoneal and pelvic cavity. The size of tumor (the maximum diameter) differed from 2 to 37 cm with a mean of 9.3 cm. The median follow-up duration was 28 (range, 6-87) months. Common side effects included: nausea and vomiting, liver injury, bone marrow suppression and oral ulcers. When the chemotherapy finished, 1 (1.4%) case achieved complete response, 24 (33.8%) achieved partial response, 37 (52.1%) achieved stable disease and 9 (12.7%) had progressive disease. The overall response rate was 87.3%. The progression-free survival (PFS) of the participants were from 6 to 87 months, and the 2-, 3- and 5-year PFS was 79.9%, 68.4% and 36.3%, respectively. No significant difference was identified in PFS in subgroups of gender, age of onset, age of chemotherapy, tumor site and tumor size.

Conclusions

For recurrent, inoperable and progressive DT, enough course of chemotherapy with vinorelbine combined with low-dose methotrexate was an optional choice for local control.

Primary and recurrent sporadic desmoids: Prognostic factors influencing recurrence-free survival after complete gross resection

INTRODUCTION

There is continuing controversy over the significance of prognostic factors in sporadic desmoid-type fibromatosis (DF). Further, only limited data is available in the literature concerning second recurrence in patients with recurrent DF. The purpose of this study was to identify prognostic factors influencing recurrence-free survival (RFS) and to determine rates of local recurrence (LR) in patients with primary and recurrent DF.

METHODS

Fifty-three consecutive patients with DF who underwent surgery at a single institution were identified. As a result of strict exclusion criteria, a homogeneous cohort of thirty-two patients who received macroscopically complete resection was included in this study and split into a primary (PG) and recurrent disease (RG) group. Clinicopathological parameters and immunohistochemical markers were retrospectively and independently analyzed in both groups.

RESULTS

The local recurrence rate was 35% for the PG and 33% for the RG. The PG's calculated median time to relapse was 17 months, and the RG's was 29 months. The estimated 1-, 5-, and 8-year RFS rates for the PG were 75%, 64%, and 55% while the corresponding RFS rates for the RG were 69%, 69%, and 52%, respectively. In primary disease, extraabdominal tumor location was the only significant adverse prognostic factor associated with worse RFS (p = 0.008). Whereas in recurrent disease, age ≥40 yrs (p = 0.022) and R0 margin status (p = 0.049) correlated with a significantly better outcome.

CONCLUSION

Recurrence in primary and recurrent DF is characterized by different predictive factors and benefits from distinct therapeutic strategies. Immunohistochemical markers are valuable tools in the diagnosis of DF, although have limited potential in predicting the outcome.

Clinical significance of midkine expression in sporadic desmoid tumors

The aim of the present study was to identify the prognostic factors for the propensity for recurrence in sporadic desmoid tumors. The catenin (cadherin-associated protein) β1 (CTNNB1) genotypes and expression of Wnt pathway proteins and midkine (also termed neurite growth-promoting factor 2) were investigated in 159 patients with sporadic desmoid tumors. Formalin-fixed paraffin-embedded tissues of the surgically resected desmoid tumors were examined by direct sequencing of CTNNB1 exon 3, and immunostained for the expression of β-catenin, T-cell factor 4 (TCF-4), phosphorylated protein kinase B (pAkt), midkine and menin using a tissue microarray method. Among the samples, 70% (111/159) exhibited point mutations of the CTNNB1 gene, including T41A (56%), S45F (8%), S45P (2%), S45N (2%) and T42A (1%). In addition, 100, 57, 24, 15 and 92% of the tumors expressed β-catenin, TCF-4, midkine, pAkt and menin, respectively. Positive midkine expression was significantly associated with the recurrence of tumors (P=0.001). The multivariate analysis of recurrence demonstrated that an extra-abdominal tumor site [hazard ratio (HR), 2.625; P=0.001] and midkine expression (HR, 2.077; P<0.009) were independent prognostic factors of tumor recurrence. In conclusion, the present results suggest that the tumor site and midkine expression may be predictive markers for the recurrence of sporadic desmoid tumors.

High-intensity focused ultrasound treatment for intra-abdominal desmoid tumors: a report of four cases

Desmoid tumors are rare clonal fibroblastic proliferations that can arise at abdominal or extra-abdominal sites. Complete surgical resection is the primary treatment for resectable desmoid tumors, but a high rate of local recurrence has been reported even after complete resection. For patients with a recurrent tumor, the goals of treatment are to control the recurrence, maintain quality of life, and prolong survival. Radiofrequency ablation, radiotherapy, chemotherapy, and other medical therapies can be used as alternative methods, but there are considerable controversies over the roles of these methods in the management of desmoid tumors. High-intensity focused ultrasound (HIFU) is a minimally invasive and effective method for treatment of solid tumors. We used HIFU to treat four patients with intra-abdominal desmoid tumors from June 2011 to September 2013. Post-procedural pain was seen in all patients. One patient had an intra-abdominal abscess and another suffered a slight injury to the femoral nerve. The patients were followed up for 19-46 months (mean 34 months) until April 2015. The tumor in one patient disappeared, and no tumor progression was observed in the other patients.

Idiopathic desmoid-type fibromatosis of the pancreatic head: case report and literature review

Desmoid-type fibromatosis (DTF) is an uncommon nonmetastatic fibrous neoplasm. Sporadic intraperitoneal DTF is rarely described in current literature. We herein report a case of DTF of unknown cause involving the pancreatic head. A 41-year-old man presented with recurrent epigastric pain and weight loss. An abdominal computed tomography scan showed a well-delineated solid cystic mass inside the pancreatic head. Pylorus-preserving pancreaticoduodenectomy was performed due to the patient's debilitating symptoms and suspected malignancy. The pathological examination revealed massive fibroblastic proliferation arising from the musculoaponeurotic tissues, consistent with a diagnosis of DTF. Immunohistochemical phenotyping determined positive immunoreactivity to vimentin and β-catenin, but negative immunoreactivity to smooth muscle actin, CD117, CD34, or S-100, confirming the diagnosis of DTF. No local recurrence or distant metastasis was found during a 24-month follow-up. Radical resection is recommended as first-line treatment for pancreatic DTF. Long-term follow-up studies are required to establish the prognosis of pancreatic DTF.

Complex reconstruction of desmoid tumor resections does not increase desmoid tumor recurrence

BACKGROUND

The propensity of desmoid tumors to develop in scars has led some surgeons to limit the complexity of desmoid defect reconstruction as a strategy for avoiding desmoid recurrence. We hypothesized that desmoid recurrence rates are similar despite the magnitude of reconstruction.

STUDY DESIGN

We retrospectively compared recurrence rates between patients who underwent reconstruction and patients who underwent primary closure without reconstruction after desmoid tumor resection in consecutive patients for 15 years. Univariate and multivariate regression analyzed associations between patient, tumor, and treatment characteristics and outcomes.

RESULTS

We included 164 consecutive patients (80 [49%] reconstructions vs 84 [51%] primary closures). Mean follow-up duration was 7.1 ± 4.5 years. Patients who underwent reconstruction had more desmoids in an area of earlier trauma or surgery (p < 0.001), greater defect volume (p < 0.01), longer operative time (p < 0.001) and hospital stay (p < 0.001), and more postoperative complications (p = 0.015) compared with the primary closure group. Despite these differences, desmoid recurrence rates were similar for the reconstruction and primary closure groups (30% and 29%, respectively; p = 0.7), as was mean time to tumor recurrence, and no tumors recurred within flap donor sites. Multivariate regression analysis demonstrated the 45F mutation to be the only independent predictor of recurrence (hazard ratio = 1.87; p = 0.04).

CONCLUSIONS

Rates of desmoid recurrence in resection defects are similar for primary closures and complex reconstructions. Therefore, surgeons should not limit the magnitude of reconstructions in an attempt to avoid tumor recurrence. However, given the propensity of desmoids to recur, reconstructions should allow for the possibility of future resections and reconstructions, particularly in tumors with 45F gene mutations.

Signal transduction pathway analysis in desmoid-type fibromatosis: transforming growth factor-β, COX2 and sex steroid receptors

Despite reports of sex steroid receptor and COX2 expression in desmoid-type fibromatosis, responses to single agent therapy with anti-estrogens and non-steroidal anti-inflammatory drugs are unpredictable. Perhaps combination pharmacotherapy might be more effective in desmoid tumors that co-express these targets. Clearly, further understanding of the signaling pathways deregulated in desmoid tumors is essential for the development of targeted molecular therapy. Transforming growth factor-β (TGFβ) and bone morphogenetic proteins (BMP) are important regulators of fibroblast proliferation and matrix deposition, but little is known about the TGFβ superfamily in fibromatosis. A tissue microarray representing 27 desmoid tumors was constructed; 14 samples of healing scar and six samples of normal fibrous tissue were included for comparison. Expression of selected receptors and activated downstream transcription factors of TGFβ family signaling pathways, β-catenin, sex steroid hormone receptors and COX2 were assessed using immunohistochemistry; patterns of co-expression were explored via correlational statistical analyses. In addition to β-catenin, immunoreactivity for phosphorylated SMAD2/3 (indicative of active TGFβ signaling) and COX2 was significantly increased in desmoid tumors compared with healing scar and quiescent fibrous tissue. Low levels of phosphorylated SMAD1/5/8 were detected in only a minority of cases. Transforming growth factor-β receptor type 1 and androgen receptor were expressed in both desmoid tumors and scar, but not in fibrous tissue. Estrogen receptor-β was present in all cases studied. Transforming growth factor-β signaling appears to be activated in desmoid-type fibromatosis and phosphorylated SMAD2/3 and COX2 immunoreactivity might be of diagnostic utility in these tumors. Given the frequency of androgen receptor, estrogen receptor-β and COX2 co-expression in desmoid tumors, further assessment of the efficacy of combination pharmacotherapy using hormonal agonists/antagonists together with COX2 inhibitors should be considered.

CTNNB1 genotyping and APC screening in pediatric desmoid tumors: a proposed algorithm

Desmoid fibromatosis is a rare, locally aggressive fibroblastic/myofibroblastic tumor that occasionally involves children. We examined a series of pediatric desmoids for CTNNB1 mutations, seen in sporadic tumors, and APC germline mutations, associated with familial adenomatous polyposis (FAP). Forty-four desmoids in pediatric patients were identified in the pathology files of 2 large referral centers (1995-2009). Clinical charts were reviewed for history of FAP. Germline APC gene mutations were determined on blood samples from patients presenting with FAP. Immunohistochemistry for beta-catenin was performed. CTNNB1 genotyping was done by Sanger sequencing on formalin-fixed paraffin-embedded tissue. CTNNB1 mutations were observed in 29 of 44 (66%) desmoids, with 3 mutations identified: T41A (64%), S45F (29%), and S45P (7%). Germline APC mutations were present in 7 (16%) desmoid patients. Eight (18%) patients had desmoids that were wild type for CTNNB1 and had no known clinical signs or family history suspicious for FAP at the time of testing or with extended follow up (n  =  6). Beta-catenin nuclear labeling was observed in 38 of 41 (92%) tested cases, 34 (89%) of which showed mutations in either CTNNB1 (n  =  29) or APC (n  =  5). Nuclear localization of beta-catenin was seen in the majority of pediatric desmoids and was most often associated with somatic mutations in CTNNB1. However, a significant proportion of pediatric patients harbored germline mutations in APC. Given the implications, genetic counseling is recommended for children diagnosed with desmoid tumors lacking CTNNB1 mutations because this population is enriched for FAP patients.

Fibroblastic and myofibroblastic tumors in children and adolescents

Fibroblastic and myofibroblastic tumors in children and adolescents are a relatively common group of soft tissue proliferations that range from reactive to hamartomatous to neoplastic, with a full spectrum of benign, intermediate, and malignant neoplasms. These lesions are diagnostically challenging because of morphologic and immunohistochemical overlap, despite significant clinical, genetic, and prognostic differences. The fibromatoses are a major subgroup, and all types of fibromatoses can occur in the 1st 2 decades of life. Intermediate and malignant fibroblastic-myofibroblastic tumors are an important group that includes variants of fibrosarcoma and other tumors with recurrent cytogenetic or molecular genetic abnormalities and low metastatic potential. Pathologic examination is enhanced by adjunct techniques, such as immunohistochemistry, cytogenetics, and molecular genetics, although morphology provides the ultimate criteria for a specific diagnosis. This article reviews the clinicopathologic features of fibroblastic and myofibroblastic tumors with an emphasis on the unique aspects of these neoplasms in children and adolescents, the use of diagnostic adjuncts, and differential diagnoses.

Update on desmoid tumors

Desmoid tumors (DTs) are histologically benign proliferations of stromal cells but may grow locally aggressive. Overall, DTs are rare (0.03% of all neoplasms). A minority of DTs is associated with Gardner syndrome and mutations of the familial adenomatous polyposis (FAP) gene. Most spontaneous DTs are associated with mutations of the beta-catenin gene. This mutation results in the activation of Wnt/catenin signaling. Due to their variable clinical presentation and behavior, no standard approach for DTs can be recommended. In most cases of DTs of the extremities surgical extirpation is indicated, whereas in many other cases, a multimodal and multidisciplinary concept should be followed. In this review article, we discuss the diagnosis, pathogenesis, and treatment options for DTs, including targeted therapy with tyrosine kinase inhibitors.

External-beam radiotherapy for pediatric and young adult desmoid tumors

BACKGROUND

To report long-term outcomes following radiotherapy for desmoid tumors in children and young adults and identify variables impacting local-regional control and treatment complications.

PROCEDURE

From 1978 to 2008, 30 patients <30 years old were treated with radiotherapy for a pathologically confirmed desmoid tumor. The median age at radiotherapy was 23.7 years old (range, 10.3-29.9). Fifteen patients underwent definitive radiotherapy, 14 received radiotherapy after gross total resection, and 1 received preoperative radiotherapy. Sixteen patients received 1.8 Gy once daily and 14 received 1.2 Gy twice daily. Variables analyzed for prognostic value included gender, age at diagnosis, primary or recurrent presentation, age at radiotherapy, tumor site, tumor size, extent of resection, fractionation schedule, and radiotherapy dose.

RESULTS

The actuarial 15-year overall survival and local-regional control rates were 96% and 55%, respectively. Local-regional control in patients <18 years old at the time of radiotherapy was 20% versus 63% in those 18-30 years old (P = 0.08). Local-regional control rates for tumors receiving ≥ 55 Gy and < 55 Gy were 79% and 30%, respectively (P = 0.02). No other factors had a statistically significant association with local-regional control by univariate analysis. Twelve of 30 patients experienced grade 3-4 complications, including pathologic fractures, impaired range of motion, pain, and in-field skin cancers.

CONCLUSIONS

The role of radiotherapy in managing young patients with desmoid tumors remains unclear. Younger patient age is associated with inferior local-regional control following RT. In children and young adults, doses ≥55 Gy were associated with improved tumor control, but also lead to increased risk of complications.

Recapitulation of fibromatosis nodule by multipotential stem cells in immunodeficient mice

Musculoskeletal fibromatosis remains a disease of unknown etiology. Surgical excision is the standard of care, but the recurrence rate remains high. Superficial fibromatosis typically presents as subcutaneous nodules caused by rapid myofibroblast proliferation followed by slow involution to dense acellular fibrosis. In this study, we demonstrate that fibromatosis stem cells (FSCs) can be isolated from palmar nodules but not from cord or normal palm tissues. We found that FSCs express surface markers such as CD29, CD44, CD73, CD90, CD105, and CD166 but do not express CD34, CD45, or CD133. We also found that FSCs are capable of expanding up to 20 passages, that these cells include myofibroblasts, osteoblasts, adipocytes, chondrocytes, hepatocytes, and neural cells, and that these cells possess multipotentiality to develop into the three germ layer cells. When implanted beneath the dorsal skin of nude mice, FSCs recapitulated human fibromatosis nodules. Two weeks after implantation, the cells expressed immunodiagnostic markers for myofibroblasts such as α-smooth muscle actin and type III collagen. Two months after implantation, there were fewer myofibroblasts and type I collagen became evident. Treatment with the antifibrogenic compound Trichostatin A (TSA) inhibited the proliferation and differentiation of FSCs in vitro. Treatment with TSA before or after implantation blocked formation of fibromatosis nodules. These results suggest that FSCs are the cellular origin of fibromatosis and that these cells may provide a promising model for developing new therapeutic interventions.

Increased midkine expression correlates with desmoid tumour recurrence: a potential biomarker and therapeutic target

Desmoid tumours (DTs) are soft tissue monoclonal neoplasms exhibiting a unique phenotype, consisting of aggressive local invasiveness without metastatic capacity. While DTs can infrequently occur as part of familial adenomatosis polyposis, most cases arise sporadically. Sporadic DTs harbour a high prevalence of CTNNB1 mutations and hence increased β-catenin signalling. However, β-catenin downstream transcriptional targets and other molecular deregulations operative in DT inception and progression are currently not well defined, contributing to the lack of sensitive molecular prognosticators and efficacious targeted therapeutic strategies. We compared the gene expression profiles of 14 sporadic DTs to those of five corresponding normal tissues and six solitary fibrous tumour specimens. A DT expression signature consisting of 636 up- and 119 down-regulated genes highly enriched for extracellular matrix, cell adhesion and wound healing-related proteins was generated. Furthermore, 98 (15%) of the over-expressed genes were demonstrated to contain a TCF/LEF consensus binding site in their promoters, possibly heralding direct β-catenin downstream targets relevant to DT. The protein products of three of the up-regulated DT genes: ADAM12, MMP2 and midkine, were found to be commonly expressed in a large cohort of human DT samples assembled on a tissue microarray. Interestingly, enhanced midkine expression significantly correlated with a higher propensity and decreased time for primary DT recurrence (log-rank p = 0.0025). Finally, midkine was found to enhance the migration and invasion of primary DT cell cultures. Taken together, these studies provide insights into potential DT molecular aberrations and novel β-catenin transcriptional targets. Further studies to confirm the utility of midkine as a clinical DT molecular prognosticator and a potential therapeutic target are therefore warranted. Raw gene array data can be found at: http://smd.stanford.edu/

Desmoid tumors: clinical features and treatment options for advanced disease

Desmoid tumors describe a rare monoclonal, fibroblastic proliferation characterized by a variable and often unpredictable clinical course. Although histologically benign, desmoids are locally invasive and associated with a high local recurrence rate, but lack metastatic potential. On the molecular level, desmoids are characterized by mutations in the β-catenin gene, CTNNB1, or the adenomatous polyposis coli gene, APC. Proof of a CTNNB1 mutation may be useful when the pathological differential diagnosis is difficult and location might be predictive for disease recurrence. Many issues regarding the optimal treatment of patients with desmoids remain controversial; however, surgery is the therapeutic mainstay, except if mutilating and associated with considerable function loss. Postoperative radiotherapy reduces the local recurrence rate, in cases of involved surgical margins. Because of the heterogeneity of the biological behavior of desmoids, including long periods of stable disease or even spontaneous regression, treatment needs to be individualized to optimize local tumor control and preserve patients' quality of life. Therefore, the application of a multidisciplinary assessment with multimodality treatment forms the basis of care for these patients. Watchful waiting may be the most appropriate management in selected asymptomatic patients. Patients with desmoids located at the mesentery or in the head and neck region could present with life-threatening complications and often need more aggressive treatment. This review describes treatment options and management strategies for patients with desmoid tumors with a focus on advanced disease.

The association between Crohn's disease and desmoid tumors: a novel case and review of the literature

Desmoids are rare tumors resulting from the proliferation of fibroblasts. They occur in association with familial adenomatous polyposis (FAP), but they may also occur in the post-traumatic peri-partum or post-abdominal surgery setting, and a few present spontaneously. Presenting features of desmoids are protean and largely relate to the anatomical area of involvement. We describe a 50 year old male not known to have Crohn's disease and without FAP who presented with multiple desmoids. Investigation of post-operative diarrhea confirmed a diagnosis of Crohn's disease. This is the first report of a male patient, who had never undergone prior abdominal surgery, presenting with Crohn's disease and abdominal desmoid tumors. The reasons why Crohn's disease and desmoids may be associated are explored, focusing particularly on alternations in the fibrogenic cytokine TGF-β now known to be involved in the pathogenesis of both diseases.