Cryoablation in Extra-Abdominal Desmoid Tumors: A 10-Year Experience in Pediatric and Young Adult Patients.

PURPOSE: To determine the efficacy and safety of cryoablation in pediatric and young adult patients with desmoid tumors (DTs) retrospectively over a 10-year period. MATERIALS AND METHODS: Twenty-one patients (age 2-22 years; median 14 years), with 21 desmoid tumors, underwent a total of 34 percutaneous cryoablation procedures between August 2013 and August 2023. All patients, excluding two, had surgical resection, chemotherapy, or a combination of these therapies with failed or suboptimal response. Clinical and imaging outcomes were analyzed for technical success, change in tumor volume, and recurrence of tumor, symptom improvement or recurrence, and procedure-related complications. RESULTS: All procedures were technically successful. The median follow-up duration was 9 months (range, 3-32 months); total symptomatic improvement was achieved in 90% (19/21) patients, noticeable pain relief was seen in 100% (18/18) and 90% (9/10) patients had improved range of motion (ROM), discomfort resolved in 66.7% (2/3) patients. Of the treated tumors, 43% (9/21) showed greater than 75% tumor volume reduction of which 44% (4/9) had no evidence of viable residual tumor at follow-up, and 33% (7/21) had 50-75% volume reduction and 14% (3/21) had greater than 40-50% tumor volume reduction. According to modified response evaluation criteria in solid tumors (mRECIST), 71%( 15/21) had partial response (PR), 19% (4/21) had complete response (CR), and 10% (2/21) had stable disease. Four (12%) treatments were associated with minor complications, which self-resolved. CONCLUSION: In this, predominantly pediatric patient cohort, cryoablation was effective and safe for the local control of extra-abdominal desmoid tumors in short-term follow-up.

Circulating Tumor DNA in Patients with Desmoid Fibromatosis during Active Surveillance.

BACKGROUND: Sporadic desmoid fibromatosis (DF) is a rare locally aggressive tumor characterized by mutation in exon 3 of CTNNB1 (T41A, S45F, and S45P). Standard of care is active surveillance (AS), but 30% require treatment. DF clinical course is unpredictable and identification of prognostic markers is needed to tailor strategy. In this prospective study, we investigated the consistency between mutation detected in tumor biopsies with that detected in plasma by digital droplet PCR (ddPCR) and the association between circulating tumor DNA (ctDNA) abundancy with clinical outcome. PATIENTS AND METHODS: A total of 56 patients and 10 healthy donors were included. CTNNB1 mutation status of DF biopsies was determined by Sanger and in case of WT CTNNB1 with NGS. In matched plasma samples at enrollment and during AS at specific timepoints, we evaluated cfDNA quantity and ctDNA. RESULTS: ctDNA levels were measured in 46 patients with CTNNB1 mutation. Detection rate for T41A, S45F and S45P was 68%, 42% and 100%, respectively. S45P variant has been detected in all patients with S45P mutation. Longitudinal assessment of ctDNA during AS in nine patients (four with regression and five with progression as first event according to RECIST) showed a concordance between the event and ctDNA level change in six out of nine patients tested (4/5 with progression and 2/4 with regression). CONCLUSIONS: Results of ctDNA analysis support its potential clinical implementation as diagnostic tool in specific clinical scenarios where biopsy can be challenging. A prospective clinical trial needs to be performed to evaluate the potential role of ctDNA as predictive biomarker.

The variable histogenesis and biology of selected bland fibroblastic lesions of the breast - pitfalls in the differential diagnostics and optimal therapeutic approach (three case reports).

Presented are three casuistics of seemingly identical breast lesions which even by adopting advanced laboratory techniques may represent diagnostic challenge. Microscopic features of some bland spindle cell lesions of different histogenesis (epithelial or mesenchymal) are misleading and a potential source of unaware errors, which might affect optimal therapeutic strategy. In the setting of three diverse entities (low-grade spindle cell metaplastic carcinoma, desmoid fibromatosis and phyllodes tumor) is documented both demanding diagnostic algorithm and revealing molecular landscape on one side as well as evolving predictive/prognostic parameters on the other one. Close interdisciplinary cooperation is inevitable for accurate interpretation/understanding of revealed diagnostic facts which is required for adjustment of competent rational and individualized therapy.

Initial treatment for surgery-naïve desmoid tumors by high intensity focused ultrasound.

Introduction: Desmoid tumor (DT) is a rare proliferative disease occurring in connective tissues, characterized by high infiltration and recurrence rates. While surgery remains the primary treatment, its recurrence risk is high, and some extra-abdominal desmoid tumors are inoperable due to their locations. Despite attempts with radiotherapy and systemic therapy, the efficacy remains limited. Methods: We used low-power cumulative high-intensity focused ultrasound (HIFU) therapy as an initial treatment for desmoid tumor patients either ineligible or unwilling for surgery. Low-power cumulative HIFU employs slower heat accumulation and diffusion, minimizing damage to surrounding tissues while enhancing efficacy. Results: Fifty-seven non-FAP desmoid tumor patients, previously untreated surgically, underwent low-power cumulative HIFU therapy. Among them, 35 had abdominal wall DT, 20 had extra-abdominal DT, and 2 had intra- abdominal DT, with an 85% median ablation ratio. Abdominal wall DT patients showed significantly better response rates (91.4% vs. 86%) and disease control rates (100% vs. 32%) than that of non-abdominal wall DT patients. Median event- free survival time was not reached after a median follow-up duration of 34 months. Discussion: With its high response rate, durable efficacy, and mild adverse effects, our findings suggest that low-power cumulative HIFU presents a promising novel treatment for desmoid tumors, particularly abdominal wall DT patients.

Setting the international research agenda for sarcomas with patients and carers: results of phase II of the Sarcoma Patient Advocacy Global Network (SPAGN) priority setting partnership.

BACKGROUND: Typically, researchers and clinicians determine the agenda in sarcoma research. However, patient involvement can have a meaningful impact on research. Therefore, the Patient-Powered Research Network (PPRN) of the Sarcoma Patient Advocacy Global Network (SPAGN) set up a Priority Setting Partnership (PSP). The primary objective of this partnership is to identify priorities for research and patient advocacy topics. METHODS: In the first phase of this PSP, including 264 sarcoma patients and carers from all over the world, 23 research topics regarding sarcomas and 15 patient advocacy topics were identified using an online survey. In the second phase, participants were asked to fill in a top five and a top three of research and patient advocacy topics, respectively. Additionally, sociodemographic characteristics and sarcoma characteristics were collected. Social media channels, local national patient advocacy groups and the SPAGN website were used to distribute the survey. RESULTS: In total, 671 patients (75%) and carers (25%) participated in this survey. The five highest ranked research topics were related to causes of sarcoma (43%), prognosis and risk of recurrence (40%), specific subtypes of sarcoma (33%), the role of immunotherapy, targeted therapy and combined therapy (30%), and hereditary aspects (30%). The three highest ranked patient advocacy topics were improving the diagnostic process of sarcoma (39%), access to tumor DNA analysis (37%) and establishing an international sarcoma registry (37%). CONCLUSIONS: This sarcoma PSP has identified priorities for research and patient advocacy, offering guidance for researchers, assisting funding agencies with assessing project relevance and empowering patient advocates to represent the needs of patients and carers.

Desmoid Tumor after Sleeve Gastrectomy: Case Report and Literature Review.

Desmoid tumor is a rare mesenchymal neoplasm of unknown etiology. Despite rare, the diagnosis of desmoid tumors after bariatric surgery is increased over the last few years. We report a case of a 26-year-old male with complains of abdominal pain and postprandial fullness, diagnosed with a locally advanced large intra-abdominal mass (40 × 21 × 11.7 cm) centered in the mesentery, developed 3 years after sleeve gastrectomy. Percutaneous biopsy was suggestive of a mesenquimatous tumor and the patient underwent surgery. R0 surgical resection was achieved, despite intimal contact and common vascularization with a jejunal loop. Histopathology examination of the surgical specimen revealed fusiform to stellate cells with mild atypia, thin-walled vessels, and diffuse beta-catenin expression (negative for DOG-1, CD117, CD34, S100, desmin, and alpha-actin). The diagnosis of a desmoid tumor was made. The patient remained asymptomatic, and no recurrence occurred over a 4-year follow-up. With the increasing number of bariatric surgeries, owing to the alarming growing incidence of obesity and related conditions, it is expected that desmoid tumors reports will gradually increase over the next few years. Thus, both gastroenterologists and surgeons should be aware of the potential for desmoid tumor development shortly after surgery, to offer a prompt diagnosis and treatment.

O tumor desmóide é uma neoplasia mesenquimatosa rara de etiologia desconhecida. Apesar de raros, temos assistido a um aumento do número de diagnósticos, ao longo dos últimos anos, de tumores desmóides que se desenvolvem após cirurgia bariátrica. Descrevemos o caso de um homem de 26 anos com queixas de dor abdominal e enfartamento pós-prandial, diagnosticado com uma massa intra-abdominal centrada no mesentério (40 × 21 × 11.7 cm), localmente avançada, 3 anos após ter realizado gastrectomia vertical. Foi efetuada biópsia percutânea, cujo resultado foi sugestivo de tumor mesenquimatoso e o paciente foi referenciado para cirurgia. O doente foi submetido a cirurgia e o tumor foi passível de ressecção cirúrgica R0, apesar de contacto íntimo e vascularização comum com uma ansa jejunal. O exame anatomopatológico revelou células fusiformes a estreladas com atipia ligeira e vasos de parede fina, bem como expressão difusa de beta-catenina (na ausência de expressão de DOG-1, CD117, CD34, S100, desmina e alfa-actina), sendo compatível com o diagnóstico de um tumor desmóide. O doente permanece assintomático e sem evidência de recidiva ao longo de 4 anos de vigilância. Com o aumento do número de cirurgias bariátricas devido ao aumento alarmante da incidência de obesidade e condições relacionadas, espera-se que os diagnósticos de tumores desmóides aumentem nos próximos anos. Assim, tanto gastroenterologistas quanto cirurgiões devem estar alerta para o desenvolvimento desta entidade, de forma a oferecer um diagnóstico e tratamento adequado e atempado.

Extensive Lateral Cervical Desmoid Tumor Dependent on the Levator Scapulae Muscle Involving the Vertebral Artery Treated by Surgical Resection and Intraoperative Navigation: A Case Report and Review of the Literature.

Desmoid tumors are rare, benign, but locally aggressive fibromatoses that pose significant therapeutic challenges, particularly when located in the head and neck region. This report details the case of an extensive cervical desmoid tumor dependent on the levator scapulae muscle and involving the vertebral artery managed through surgical resection and intraoperative navigation. A 45-year-old male presented with a slowly growing cervical mass. Imaging revealed an 83x68x40 mm mass in the right lateral paravertebral space, dependent on the levator scapulae muscle and involving the vertebral artery. Biopsy confirmed a low-grade fusocellular myofibroblastic neoplasm consistent with a desmoid tumor. Given the poor prognosis associated with the symptomatic mass, surgical resection was performed using Brainlab intraoperative navigation (Brainlab, Munich, Germany). The procedure was successful, with preservation of vital structures and no evidence of recurrence postoperatively. Desmoid tumors in the head and neck region, though rare, require precise diagnostic and therapeutic approaches due to their aggressive nature and proximity to critical anatomical structures. The use of intraoperative navigation, in this case, facilitated accurate tumor resection, minimizing damage to surrounding tissues. Pathological analysis revealed a CTNNB1 gene mutation, specifically the S45P variant, which is associated with an increased risk of recurrence. This case highlights the importance of a multidisciplinary approach, incorporating advanced surgical techniques and genetic analysis, in the management of complex desmoid tumors. Intraoperative navigation proved invaluable in achieving successful surgical outcomes, underscoring its potential utility in similar cases. Continued follow-up is essential, given the potential for recurrence associated with desmoid tumors.

Evolution of Initial Treatment for Desmoid Tumors.

INTRODUCTION: Desmoid tumors (DTs) are rare, fibroblastic cell proliferations that can exhibit locally aggressive behavior but lack metastatic potential. Initial management has traditionally involved upfront resection; however, contemporary guidelines and expert panels have increasingly advocated for prioritizing active surveillance strategies. METHODS: A single-institution, retrospective chart review identified all patients diagnosed with a primary DT at any site from 2007 to 2020. The primary outcome was the initial management strategy over time. Secondary outcomes included treatment-free survival (TFS) and time to treatment (TTT) for those undergoing active surveillance, as well as recurrence-free survival (RFS) and time to recurrence for those undergoing resection. RESULTS: Overall, 103 patients were included, with 68% female and a median follow-up of 44 months [24-74]. The most common tumor locations included the abdominal wall (27%), intra-abdominal/mesenteric (25%), chest wall (19%), and extremity (10%). Initial management included resection (60%), systemic therapy (20%), active surveillance (18%), and cryoablation (2%). Rates of surgical resection significantly decreased (p < 0.001) over time, from 69.6% prior to 2018 to 29.2% after 2018. For those treated with upfront resection, 5-year RFS was 41.2%, and for patients undergoing initial active surveillance, TFS was 66.7% at 2 years, with a median TTT of 4 months [4-10]. CONCLUSIONS: This single-institution cohort at a tertiary medical center spanning over a decade demonstrates the transition to active surveillance for initial management of DTs, and highlights salient metrics in the era of surveillance. This trend mirrors recommended treatment strategies by expert panels and consensus guidelines.

First Description of the Clinical Activity of Avapritinib in Sporadic Mesenteric Desmoid Tumor.

Desmoid tumors (DTs) are rare and locally aggressive with a high rate of local recurrence even with optimal surgical resection. Systemic treatments are often utilized for desmoid cases with high risk of surgical morbidity or for local and symptomatic control of recurrent disease. However, the systemic treatment options for DTs are limited with limited responses. Avapritinib is a tyrosine kinase inhibitor (TKI) approved in 2020 for adults with unresectable or metastatic gastrointestinal (GI) stromal tumors (GISTs) harboring a platelet-derived growth factor receptor alpha (PDGFRA) Exon 18 mutation, including D842V mutations. In this case report, we describe a 55-year-old man with a history of D842V-mutant gastric GIST who presented several years after complete resection of the GIST with an enlarging soft tissue mass in the small intestine. After a nondiagnostic biopsy, the patient was started on avapritinib due to concerns for recurrent D842V-mutant GIST. The tumor had a partial response to treatment by RECIST 1.1 criteria, and the patient underwent surgical resection. The final pathology report revealed a sporadic DT. To our knowledge, this is the first known description of the activity of avapritinib in the treatment of a sporadic mesenteric DT, which is relevant given the limited treatment options for patients with this diagnosis. This clinical finding may be worth exploring in a dedicated clinical trial.

Management of a Large Abdominal Desmoid Tumor Complicated by Lymphedema of the Lower Limb: A Case Report.

Desmoid tumors, while generally benign histologically, can exhibit locally aggressive behavior, especially when located in the anterior abdominal wall. This case report explores the management of a rare giant desmoid tumor complicated by concurrent lymphedema, emphasizing the nuances of diagnosis, treatment decisions, and their impact on the patient's quality of life. The patient, a 55-year-old obese individual with a BMI of 47, presented with a 25 cm mass in the right paraumbilical region, alongside significant lymphedema in the right lower limb and associated inguinal lymphadenopathy. Abdominal CT revealed a well-defined soft tissue mass in the right paramedian hypogastric region, suggestive of a desmoid tumor. Surgical intervention involved a monobloc resection of the mass with a 5 cm lateral margin, including the right rectus abdominis muscle and associated aponeuroses, and subsequent reconstruction using a biface intraperitoneal synthetic mesh. Postoperative recovery was marked by the resolution of lymphedema and a return to full function of the affected limb. Histopathological examination confirmed the diagnosis of a desmoid tumor. This case underscores the importance of radical surgical resection with adequate margins and appropriate reconstruction to achieve favorable long-term outcomes. The report provides insights for future research and therapeutic advancements in the management of desmoid tumors.

Transarterial doxorubicin-eluting beads embolization for the treatment of desmoid fibromatosis in the pubic region.

Desmoid fibromatosis (DFs) is rare, low-grade neoplasm. Although it poses no risk of metastasis, DFs exhibits a range of clinical manifestations characterized by local infiltrative growth tendencies and a propensity for recurrence. Despite its nonmalignant nature, DFs can be highly debilitating and occasionally life-threatening, causing severe pain and functional limitations. Traditionally, surgery served as the conventional primary treatment approach; nevertheless, a recent shift in paradigm towards a more conservative management has emerged, accompanied by efforts to standardize the strategy among clinicians. Systemic doxorubicin has been demonstrated to be effective in treating DFs; however, it carries potential risks of adverse effects on the cardiovascular, digestive, and hematologic systems. The novel intravascular intervention employing drug-eluting beads loaded with doxorubicin represents an effective treatment for DFs, optimizing drug delivery to the target lesion and reducing systemic toxicity. In this article, we present a rare case of DFs in the right pubic region treated with transarterial doxorubicin-eluting beads embolization.

Aggressive fibromatosis of the sigmoid colon: A case report.

BACKGROUND: Aggressive fibromatosis (AF), also known as desmoid tumor or desmoid-type fibromatosis, is a rare soft tissue neoplasm that can occur in almost any part of the body. Although it is a benign disease, AF is aggressive and infiltrative and has a high recurrence rate after surgery. Common sites for intra-abdominal AF are the small bowel mesentery, retroperitoneum, and pelvis. AF in the colon is extremely rare. CASE SUMMARY: Here, we report the first case of sigmoid colon AF, which was accidentally discovered in a 27-year-old woman during laparoscopic myomectomy. Computed tomography confirmed a slightly enhanced mass in the sigmoid colon. Subsequent colonoscopy did not reveal a mass in the colonic lumen, but a suspected external compress was found in the sigmoid colon. Surgical disease involving a gastrointestinal stromal tumor was suspected. The patient underwent laparoscopic exploration, and sigmoidectomy with a negative margin was performed to excise the mass. Postoperative immunohistochemistry revealed that the mass was an AF. The patient recovered well and was recurrence-free at the 30-month follow-up without adjuvant therapy. CONCLUSION: AF should be considered in the differential diagnosis of subepithelial colon masses. Radical resection alone can achieve good outcomes.

Prognostic impact of tumor location and gene expression profile in sporadic desmoid tumor.

PURPOSE: Prognostic biomarkers remain necessary in sporadic desmoid tumor (DT) because the clinical course is unpredictable. DT location along with gene expression between thoracic and abdominal wall locations was analyzed. METHOD: Sporadic DT patients (GEIS Registry) diagnosed between 1982 and 2018 who underwent upfront surgery were enrolled retrospectively in this study. The primary endpoint was relapse-free survival (RFS). Additionally, the gene expression profile was analyzed in DT localized in the thoracic or abdominal wall, harboring the most frequent CTNNB1 T41A mutation. RESULTS: From a total of 454 DT patients, 197 patients with sporadic DT were selected. The median age was 38.2 years (1.8-89.1) with a male/female distribution of 33.5/66.5. Most of them harbored the CTNNB1 T41A mutation (71.6 %), followed by S45F (17.8 %) and S45P (4.1 %). A significant worse median RFS was associated with males (p = 0.019), tumor size ≥ 6 cm (p = 0.001), extra-abdominal DT location (p < 0.001) and the presence of CTNNB1 S45F mutation (p = 0.013). In the multivariate analysis, extra-abdominal DT location, CTNNB1 S45F mutation and tumor size were independent prognostic biomarkers for worse RFS. DTs harboring the CTNNB1 T41A mutation showed overexpression of DUSP1, SOCS1, EGR1, FOS, LIF, MYC, SGK1, SLC2A3, and IER3, and underexpression of BMP4, PMS2, HOXA9, and WISP1 in thoracic versus abdominal wall locations. CONCLUSION: Sporadic DT location exhibits a different prognosis in terms of RFS favoring the abdominal wall compared to extra-abdominal sites. A differential gene expression profile under the same CTNNB1 T41A mutation is observed in the abdominal wall versus the thoracic wall, mainly affecting the Wnt/ß-catenin, TGFß, IFN, and TNF pathways.

Development of Desmoid Tumors After Ileorectal Anastomosis Versus Ileal Pouch-Anal Anastomosis in Familial Adenomatous Polyposis.

BACKGROUND & AIMS: Desmoid tumors (DT) are an important cause of morbidity and mortality in patients with familial adenomatous polyposis (FAP). DT development might be related to the type and approach of colectomy. We aimed to compare DT development after colectomy with ileorectal anastomosis (IRA) and proctocolectomy with ileal pouch-anal anastomosis (IPAA). METHODS: We performed an international historical cohort study in patients with FAP who underwent IRA or IPAA between 1961 and 2020. The primary outcome was the incidence of abdominal DT (either mesenteric, retroperitoneal, or abdominal wall). Patients with a DT diagnosis before or at colectomy were excluded. Time to DT was considered censored at an eventual secondary proctectomy after IRA. We used multivariable Cox regression modelling to adjust for potential confounders. RESULTS: We analyzed data from 852 patients: 514 after IRA and 338 after IPAA (median follow-up, 21 and 16 years, respectively). DTs were diagnosed in 64 IRA patients (12%) and 66 IPAA patients (20%). The cumulative DT incidence at 5 and 10 years was 7.5% and 9.3% after open IRA and 4.7% and 10.9% after laparoscopic IRA. These estimates were 13.6% and 15.4% after open IPAA and 8.4% and 10.0% after laparoscopic IPAA. The postoperative risk was significantly higher after IPAA (P < .01) in multivariable analysis, whereas approach did not significantly influence the risk. CONCLUSIONS: The risk of developing an abdominal DT was found to be significantly higher after IPAA than after IRA. Postoperative DT risk should be taken into account when choosing between IRA and IPAA in FAP.

Contrast-enhanced ultrasonography combined with superb microvascular imaging for preoperative diagnosis of sporadic intra-abdominal desmoid-type fibromatosis: A case report.

We herein report a case of sporadic intra-abdominal desmoid-type fibromatosis in which contrast-enhanced ultrasonography (US) combined with superb microvascular imaging (SMI) was useful for preoperative diagnosis. 18-Fluorodeoxyglucose positron emission tomography performed for systematic screening for lung cancer revealed an abnormal accumulation in the abdominal cavity. Transabdominal US showed a tumor with a mixture of hypoechoic and hyperechoic areas. Contrast-enhanced US combined with SMI revealed dendritic blood flow signals and no abnormal vascular network within the tumor. Macroscopic examination of the resected specimen revealed a white tumor with relatively clear boundaries. Microscopic examination revealed spindle cells with poor atypia proliferating in bundles with collagenous stromal cells. Immunohistochemistry showed nuclear localization of beta-catenin within the tumor cells. From these findings, we finally diagnosed intra-abdominal desmoid-type fibromatosis. Contrast-enhanced US combined with SMI is useful for diagnosing intra-abdominal desmoid-type fibromatosis.

Desmoid Tumor of the Rectus Abdominis Muscle: A Case Report.

Desmoid tumors, also referred to as aggressive fibromatosis, represent an uncommon form of fibroblastic proliferation. These neoplasms may arise within any musculoaponeurotic structure throughout the body. They are classified as benign due to several distinctive features: histologically, they exhibit regular mitotic activity and are devoid of metastatic potential. Computed tomography (CT) remains the definitive modality for precise diagnosis, and surgical excision is strongly advised. This account details the manifestation of a desmoid tumor located in the anterior abdominal wall of a 31-year-old female patient who notably lacks any prior surgical interventions. The surgical intervention entailed the excision of the neoplasm and subsequent reconstruction of the abdominal wall utilizing a polypropylene mesh. Postoperatively, the patient was released from the medical facility after a period of three days, having experienced no post-surgical complications. This was followed by a six-month interval free of any adverse events.

Local Treatment of Desmoid Tumors: An Update.

Desmoid tumors (DTs) are rare fibroblastic proliferations, characterized by infiltrative growth and a propensity for local recurrence. Traditional strategies such as surgery, radiotherapy, and chemotherapy are the mainstays of treatment, each with its limitations and associated risks. The trend in DT management leans toward a "wait-and-see" strategy, emphasizing active surveillance supported by continuous MRI monitoring. This approach acknowledges the unpredictable nature of the disease, and a multidisciplinary management of DT requires a nuanced approach, integrating traditional therapies with emerging interventional techniques. This review highlights the emerging role of minimally invasive interventional radiological technologies and discusses interventional radiology techniques, including chemical, radiofrequency, microwave, cryoablation, and high-intensity focused ultrasound ablations as well as transarterial embolization.

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.

CLINICAL AND EPIDEMIOLOGIC EVALUATION OF DESMOID TUMORS IN A BRAZILIAN SARCOMA REFERENCE CENTER.

Introduction: Desmoid Tumors (DT) are rare neoplasms with higher incidence in younger women. Methods: Retrospective, single-center analysis of patients with DT. Variables were age, sex, biopsy, treatment and recurrence. The disease-free survival (DFS) was calculated with the Kaplan-Meier method. Results: 242 patients were evaluated, mean age was 34 years, 70.7% women, 44.4% originated in the trunk/abdomen and 54.5% had size > 5cm. Surgery was performed in 70.2%, 31% with negative margin and only 57% with previous biopsy. Recurrence rate was 38% and 1,2,5-year DFS was 75.3%, 64.2%, 57.8%, respectively. Size (p = 0.018) and tumor location in the dorsum (p = 0.001), extremities (p = 0.003) and pelvis (p = 0.003) were related to higher relapse rate. Conclusion: our data reinforces the need to gather data from real world practice and the importance of awareness of DT and medical education about DT behavior and best approach due to the high rates of surgery and elevated number of patients treated without biopsy. Level of Evidence III; Retrospective Comparative Study.

Introdução: Os tumores desmóides (TD) são neoplasias raras com maior incidência em mulheres jovens. Métodos: Trata-se de uma análise retrospectiva, em um único centro, de pacientes com TD. As variáveis foram idade, sexo, biópsia, tratamento e recorrência. A sobrevida livre de doença (SLD) foi calculada pelo método de Kaplan-Meier. Resultados: Foram avaliados 242 pacientes, com idade média de 34 anos, 70,7% mulheres, 44,4% com origem no tronco/abdômen e 54,5% com tamanho > 5 cm. A cirurgia foi realizada em 70,2%, 31% com margem negativa e apenas 57% com biópsia prévia. A taxa de recorrência foi de 38% e a SLD de 1, 2 e 5 anos foi de 75,3%, 64,2% e 57,8%, respectivamente. O tamanho (p = 0,018) e a localização do tumor no dorso (p = 0,001), nas extremidades (p = 0,003) e na pelve (p = 0,003) foram relacionados a uma maior taxa de recidiva. Conclusão: Nossos dados reforçam a necessidade de coletar dados da prática do cenário real e a importância da conscientização da TD e da educação médica sobre o comportamento da TD e a melhor abordagem, devido às altas taxas de cirurgia e ao elevado número de pacientes tratados sem biópsia. Nível de Evidência III; Estudo Comparativo Retrospectivo.