Modern Approach to Melanoma Adjuvant Treatment with Anti-PD1 Immune Check Point Inhibitors or BRAF/MEK Targeted Therapy: Multicenter Real-World Report.

BACKGROUND: The landscape of melanoma management changed as randomized trials have launched adjuvant treatment. MATERIALS AND METHODS: An analysis of data on 248 consecutive melanoma stage III and IV patients given adjuvant therapy in eight centers (February 2019 to January 2021) was conducted. RESULTS: The analyzed cohort comprised 147 melanoma patients given anti-PD1 (33% nivolumab, 26% pembrolizumab), and 101 (41%) were given dabrafenib plus trametinib (DT). The 2-year overall survival (OS), relapse-free survival (RFS), and distant-metastases-free survival (DMFS) rates were 86.7%, 61.4%, and 70.2%, respectively. The disease stage affected only the RFS rate; for stage IV, it was 52.2% (95% CI: 33.4-81.5%) vs. 62.5% (95% CI: 52.3-74.8%) for IIIA-D, p = 0.0033. The type of lymph node surgery before adjuvant therapy did not influence the outcomes. Completion of lymph node dissection cessation after positive SLNB did not affect the results in terms of RFS or OS. Treatment-related adverse events (TRAE) were associated with longer 24-month RFS, with a rate of 68.7% (55.5-84.9%) for TRAE vs. 56.6% (45.8-70%) without TRAE, p = 0.0031. For TRAE of grade ≥ 3, a significant decline in OS to 60.6% (26.9-100%; p = 0.004) was observed. CONCLUSIONS: Melanoma adjuvant therapy with anti-PD1 or DT outside clinical trials appears to be effective and comparable with the results of registration studies. Our data support a de-escalating surgery approach in melanoma treatment.

Prognostic value of coronary atherosclerosis and CAC score for the risk of chemotherapy-related cardiac dysfunction (CTRCD): The protocol of ANTEC study.

BACKGROUND: Cardiological complications of oncological treatment, including the most serious one, heart failure, constitute a significant and still unsolved clinical problem. A history of dyslipidemia and complications of atherosclerosis, including coronary artery disease, are established risk factors for cardiotoxicity in cancer patients. In recent years, a protective effect of statin treatment on the development of heart failure in cancer patients has been observed. This protocol describes a study aiming to assess the prognostic value of coronary atherosclerosis burden and the CAC score on the onset of cardiac dysfunction associated with cancer therapy. METHODS: ANTEC (Atherosclerosis iN chemoTherapy-rElated Cardiotoxicity) is a single-site, prospective, observational study to evaluate the influence of the coronary atherosclerosis and CAC score assessed by computed tomography on the development of left ventricular systolic dysfunction in cancer patients with at least moderate cardiotoxicity risk. A group of 80 patients diagnosed with cancer prior to high-dose anthracycline chemotherapy (doxorubicin ≥ 240 mg / m2 body weight or epirubicin ≥ 600 mg / m2 body weight), without a history of heart failure and coronary artery disease, will be included in the study. Patient follow-up is planned for 12 months. In all patients, coronary computed tomographic angiography (CCTA) will be performed once at the beginning of the study. The primary endpoint is the onset of cancer therapy-related cardiovascular toxicity, defined as mild, moderate, severe and very severe according to ESC 2022 Cardio-oncology guidelines. During follow up, echocardiography with GLS assessment will be performed every three months. Additionally, new biomarkers of atherosclerosis (IL-6, MPO, TNF-alpha) will be measured every 6 months. The study registration identifier on clinicaltrials.gov is NCT05118178. CLINICAL TRIALS REGISTRY: This study is listed on cinicaltrials.gov with identifier NCT05118178.

Predictive Biomarkers of Pathological Response to Neoadjuvant Chemoradiotherapy for Locally Advanced Soft Tissue Sarcomas.

BACKGROUND: Marginally resectable and unresectable soft tissue sarcomas (STS) remain a therapy challenge due to the lack of highly active treatment. The aim of the study was to identify a biomarker to predict the pathological response (PR) to preplanned treatment of these STSs. METHODS: In the phase II clinical trial (NCT03651375), locally advanced STS patients received preoperative treatment with a combination of doxorubicin-ifosfamide chemotherapy and 5 × 5 Gy radiotherapy. PR to the treatment was classified using the European Organization for Research and Treatment of Cancer-Soft Tissue and Bone Sarcoma Group recommendations. We have chosen HIF-1α, CD163, CD68, CD34, CD105, and γH2AFX proteins, rendering different biological phenomena, for biomarker study. RESULTS: Nineteen patients were enrolled and in four cases a good PR was reported. The high expression of HIF-1α before surgery showed a negative correlation with PR, which means a poor response to therapy. Furthermore, the samples after surgery had decreased expression of HIF-1α, which confirmed the correlation with PR. However, high expression of γH2AFX positively correlated with PR, which provides better PR. The high number of positive-staining TAMs and the high IMVD did not correlate with PR. CONCLUSIONS: HIF1α and γH2AFX could be potential biomarkers for PR prediction after neoadjuvant treatment in STS.

Nivolumab + relatlimab for the treatment of unresectable or metastatic melanoma.

INTRODUCTION: Though melanoma is one of the less common skin malignancies, it accounts for the majority of deaths due to cutaneous cancers. The recent progress and drug approvals in targeted treatment and immunotherapy revolutionized the outcome of patients with metastatic disease, and now is also changing the landscape of adjuvant treatment in melanoma. AREA COVERED: A combination of anti-PD-1 and anti-CTLA-4 (nivolumab with ipilimumab) has demonstrated superior outcomes in terms of progression-free survival (PFS) and overall survival with recent data confirming median survival exceeding six years. However, the use of this immunotherapy combination is limited in routine practice to approximately half of the patients due to high toxicity with the majority of patients at risk of severe adverse events. The current efforts are to determine how best to integrate combination immunotherapy in different clinical scenarios and limit these drugs' toxicity. That is why novel strategies in immunotherapy are needed and one of the examples of such novelty are anti-LAG-3 antibodies (lymphocyte-activation gene 3). LAG-3 inhibitor (relatlimab) in combination with nivolumab significantly improved PFS as compared to anti-PD-1 monotherapy in patients with previously untreated metastatic or unresectable melanoma. We describe the current status of combination of nivolumab+ relatlimab in the treatment of advanced melanoma patients based on the available data coming from pivotal clinical trials. EXPERT OPINION: The most important question to be answered is what would be the place of this novel combination in the treatment planning strategy.

Management of Myxofibrosarcoma and Undifferentiated Pleomorphic Sarcoma.

Undifferentiated pleomorphic sarcoma (UPS) and myxofibrosarcoma (MFS) are genomically complex tumors commonly diagnosed in the extremities or trunk of elderly patients. They likely represent a spectrum of disease differentiated by myxoid stroma and curvilinear vessels observed in MFS but not in UPS. Limb-sparing surgery is the standard of care although the infiltrative nature of MFS mandates wider resection margins than are necessary for UPS. UPS are conversely associated with high risks of distal recurrence, often prompting recommendations for adjuvant chemotherapy. In both histologies, anthracycline-based therapies or gemcitabine and docetaxel are used to manage advanced disease; immunotherapy may be of benefit in a subset of patients.

Immune-Related Thyroid Adverse Events Predict Response to PD-1 Blockade in Patients with Melanoma.

Antibodies against programmed cell death protein-1 or its ligand (PD-(L)1) are a standard of care in melanoma; however, this treatment may cause immune-related adverse events. The aim of this study was to evaluate the immune-related thyroid adverse events (irTAEs) during anti-PD-1 therapy and analyze their influence on the overall survival rates in melanoma. We included 249 patients with metastatic melanoma treated in our institution between 2014 and 2021; the median age was 62 years (range: 17-90); 58% were males, and 37% of patients had the BRAF mutation. We included patients with a normal TSH at baseline and followed up with measurement of TSH levels during immunotherapy. In our group, 95 patients had a TSH outside the normal range: 63 not clinically significant and 32 with clinical symptoms of hypothyroidism. The 3-year overall survival rate was related to the irTAEs of clinical hypothyroidism, abnormal clinically not significant TSH, and euthyreosis at 56%, 43%, and 32%, respectively (p = 0.002). After adjusting the Cox model for potential confounding variables, clinically significant hypothyroidism was an independent prognostic factor with HR 0.51 (95% CI 0.29-0.87). In conclusion, the patients who developed clinically significant hypothyroidism requiring replacement therapy with L-thyroxin were the group who benefitted most from anti-PD-1 treatment.

The Use of ctDNA for BRAF Mutation Testing in Routine Clinical Practice in Patients with Advanced Melanoma.

Assessment of BRAF mutation status is mandatory in advanced, treatment-naïve melanoma patients. Liquid biopsy can be an alternative in cases with inadequate or unavailable tumor tissue. The aim of our study was to evaluate the clinical utility of plasma circulating tumor DNA analysis for BRAF mutation testing and to assess outcomes of therapy with BRAF/MEK inhibitors initiated based on the liquid biopsy results. This was a retrospective single-center analysis of 46 patients (21 female, 25 male) with advanced melanoma who underwent circulating tumor DNA (ctDNA) BRAF mutation testing. A BRAF mutation was found in 45.7% (21/46) of liquid biopsies and 44.8% (13/29) of tissue samples. In patients with both ctDNA and tissue samples (n = 29), the concordance between the results of both tests was 82.8%. A BRAF mutation was detected in 7/17 (41.2%) patients with only ctDNA analysis. In 18 patients, therapy with BRAF/MEK inhibitors was initiated on the basis of the result of liquid biopsy. The objective response rate was 77.8 %, and the median PFS was 6.0 months. Our study confirms the clinical utility of BRAF mutation detection in plasma ctDNA. This study provides initial real-world data showing that treatment with BRAF/MEK inhibitors could be commenced based on liquid biopsy results.

Treatment of Locally Advanced Merkel Cell Carcinoma-A Multi-Center Study.

Merkel cell carcinoma (MCC) is a rare, aggressive skin cancer with a high risk of recurrence and poor prognosis. The treatment of locally advanced disease involves surgery and radiotherapy. To analyze real-life treatment patterns and clinical outcomes, we conducted a retrospective analysis of data from 161 MCC patients treated with curative intent in four oncological centers in Poland. The median age at diagnosis was 72 years (30-94); 49.7% were male. Lymph node (LN) involvement at diagnosis was found in 26.9% of patients. Sentinel lymph node biopsy (SLNB) was performed in 36.5% of patients (positive in 10.5%), and 51.9% of patients received perioperative treatment. The relapse rate was 38.3%. With the median follow-up of 2.3 years, the median disease-free survival (DFS) was not reached, and the 1-year rate was 65%. The negative independent risk factors for DFS were male gender, metastases in LN at diagnosis, no SLNB in patients without clinical nodal metastases, and no perioperative radiotherapy. The estimated median overall survival (OS) was 6.9 years (95% CI 4.64-9.15). The negative independent risk factors for OS were male gender, age above 70, metastases in LN at diagnosis, and no SLNB in patients without clinical nodal metastases. Our results confirm that the MCC treatment should be conducted in an experienced multidisciplinary team; however, the outcomes are still unsatisfactory.

Age as a Prognostic Factor in Patients with Ewing Sarcoma-The Polish Sarcoma Group Experience.

Ewing sarcoma (ES) is a rare and aggressive disease that requires multidisciplinary treatment with the use of chemotherapy, radiotherapy, and surgery. Our retrospective study aimed to analyze the prognostic factors and treatment results in different age groups of patients. Between 1998 and 2018, 569 patients with ES were treated in two referral centers. The patients were divided into four age groups (≤10 years; 11-18 years; 19-25, and >25). The treatment results and prognostic factors were assessed for each group. For statistical analyses, we used the Chi2 test, the Kaplan-Meier estimator with a log-rank test, and the multivariate Cox model. Five-year overall survival (OS) rate was 56%. In the age subgroups: ≤10 years, 11-18 years, 19-25 years, and >25 years, the 5-year OS rates were 75%, 58%, 41%, and 52%, respectively. Favorable prognostic factors: female gender (p = 0.024), non-axial localization (p = 0.005), VIDE regimen (p < 0.001), and surgery as a local treatment (p < 0.001) dominated in the group ≤10 years. In multivariate analysis, male (HR = 1.53), axial localization (HR = 1.46), M1 status at presentation (HR = 2.64), and age > 10 years (HR = 2.29) were associated with shorter OS. The treatment results in ES are significantly better in children aged ≤10 years; the challenge is to provide therapy for adolescents and young adults. The diagnostics and treatment of ES patients must be provided in referral centers.

Efficacy and Safety of Hypofractionated Preoperative Radiotherapy for Primary Locally Advanced Soft Tissue Sarcomas of Limbs or Trunk Wall.

BACKGROUND: The use of adjuvant radiotherapy (RT) shows a significantly decreased incidence of local recurrence (LR) in soft tissue sarcomas (STS). This study aimed to assess the treatment scheme's effect in patients with primary STS treated at one institution. METHODS: In this phase 2 trial, 311 patients aged ≥18 years with primary, locally advanced STS of the extremity or trunk wall were assigned to multimodal therapy conducted at one institution. The preoperative RT scheme consisted of 5 Gy per fraction for a total dose of 25 Gy. Surgery was performed within 2-4 days from the last day of RT. The primary endpoint was LR-free survival (LRFS). Adverse events of the treatment were assessed. RESULTS: We included 311 patients with primary locally advanced STS. The median tumor size was 11 cm. In total, 258 patients (83%) had high-grade tumors. In 260 patients (83.6%), clear surgical margins (R0) were obtained. Ninety-six patients (30.8%) had at least one type of treatment adverse event. LR was observed in 13.8% patients. The 5-year overall survival was 63%. CONCLUSION: In this group, with a significant percentage of patients with extensive, high-grade STS, hypofractionated preoperative RT was associated with good local control and tolerance.

What is the best front-line approach in patients with desmoid fibromatosis? - A retrospective analysis from a reference center.

INTRODUCTION: Desmoid fibromatosis (DF) is a locally aggressive, not metastasizing tumor associated with high local recurrence rates. Surgery was a standard-of-care for DF treatment; however, recently, conservative treatment and active surveillance are preferred. This study aimed to evaluate the real-life outcomes of DF treatment. MATERIALS AND METHODS: All consecutive patients diagnosed with DF and treated between 01.1999 and 12.2018 at one sarcoma reference institution were included in this retrospective analysis. Kaplan-Meier estimator, long-rank test, Cox regression model, and Chi2 tests were used for statistical analyses. RESULTS: The analyses included 363 patients (254 female, 109 male). 195 patients (53.7%) underwent surgical resection, and 139 (38.3%) experienced a watch-and-wait approach with or without concomitant therapy with nonsteroid anti-inflammatory drugs (NSAIDs) in the first line. Disease recurrence/progression occurred in 43.2% of patients treated with surgery and 42.6% in the watch-and-wait group, resulting in 5-year event-free survival (EFS) rates of 60% and 55%, respectively. There was no difference in EFS between both groups (HR1.28, 95%CI 0.91-1.79). Surgery without prior biopsy and extra-abdominal wall location was associated with inferior outcomes. CONCLUSIONS: Results of DF treatment in our center showed that watch-and-wait approach ± NSAIDs has similar efficacy to upfront surgery and allows to avoid unnecessary surgery in approximately half of the patients, primarily when tumors are located in unfavorable sites, like extremities.

Combined Preoperative Hypofractionated Radiotherapy With Doxorubicin-Ifosfamide Chemotherapy in Marginally Resectable Soft Tissue Sarcomas: Results of a Phase 2 Clinical Trial.

PURPOSE: There is no standard treatment for marginally resectable soft tissue sarcomas (STSs) of the extremities and trunk wall, and current approaches produce unsatisfactory results. We hypothesized that the combination of doxorubicin-ifosfamide (AI) chemotherapy and 5 × 5 Gy hypofractionated radiotherapy can generate a higher ratio of limb-sparing or conservative surgeries with negative microscopic margins (R0) and acceptable treatment toxicity. METHODS AND MATERIALS: We conducted a single-arm prospective clinical trial. Treatment combined 1 cycle of AI with subsequent 5 × 5 Gy radiotherapy within 1 week, followed by 2 cycles of AI and surgery. The primary endpoint was to assess the number of patients in whom en bloc R0 resection was achieved. RESULTS: Forty-six patients met the eligibility criteria. Three patients had resectable lung metastases at baseline. Forty-two received the planned protocol treatment. In 2 patients, the treatment was prematurely stopped because of the toxicity of chemotherapy. One patient died of septic shock because of severe bone marrow suppression after the second AI cycle; a second death was not related to treatment for STS. Three patients underwent amputation. In 72% of patients in the intention-to-treat analysis, we achieved en bloc R0 resections. Grade 3+ Common Terminology Criteria for Adverse Events 4.03 chemotherapy toxicity requiring dose reduction or treatment interruption occurred in 15 patients. Wound complications occurred in 18 patients, but they were severe in only 6 patients. CONCLUSIONS: Preoperative AI combined with 5 × 5 Gy radiotherapy is a promising method for the management of marginally resectable STS. This protocol enables a high ratio of R0 limb-sparing or conservative surgeries. Further evaluation of this strategy is warranted.

Efficacy of Neoadjuvant Targeted Therapy for Borderline Resectable III B-D or IV Stage BRAF V600 Mutation-Positive Melanoma.

Neoadjuvant therapy for locally advanced disease or potentially resectable metastatic melanoma is expected to improve operability and clinical outcomes over upfront surgery and adjuvant treatment as it is for sarcoma, breast, rectal, esophageal, or gastric cancers. Patients with locoregional recurrence after initial surgery and those with advanced regional lymphatic metastases are at a high risk of relapse and melanoma-related death. There is an unmet clinical need to improve the outcomes for such patients. Patients with resectable bulky stage III or resectable stage IV histologically confirmed melanoma were enrolled and received standard-dose BRAFi/MEKi for at least 12 weeks before feasible resection of the pre-therapy target and then received at least for the next 40 weeks further BRAFi/MEKi. Of these patients, 37 were treated with dabrafenib and trametinib, three were treated with vemurafenib and cobimetinib, five with vemurafenib, and one with dabrafenib alone. All patients underwent surgery with 78% microscopically margin-negative resection (R0) resection. Ten patients achieved a complete pathological response. In patients with a major pathological response with no, or less than 10%, viable cells in the tumor, median disease free survival and progression free survival were significantly longer than in patients with a minor pathological response. No patient discontinued neoadjuvant BRAFi/MEKi due to toxicity. BRAFi/MEKi pre-treatment did not result in any new specific complications of surgery. Fourteen patients experienced disease recurrence or progression during post-operative treatment. We confirmed that BRAFi/MEKi combination is an effective and safe regimen in the perioperative treatment of melanoma. Pathological response to neoadjuvant treatment may be considered as a surrogate biomarker of disease recurrence.

The analysis of 3-year adjuvant therapy with imatinib in patients with high-risk molecular profiled gastrointestinal stromal tumors (GIST) treated in routine practice.

INTRODUCTION: The real-world data on adjuvant imatinib therapy in high-risk primary GIST are scarce. METHODS: We have analysed the data of 107 consecutive patients with gastrointestinal stromal tumour (GIST) after resection treated with adjuvant imatinib (for planned 3 years with initial dose 400 mg daily, started not later than 4 months after operation) in 6 oncological centres in 2013-2018. All patients were required to have high risk of recurrence (at least 50% according to NCCN/AFIP criteria), known mutational status to exclude PDGFRA D842V mutants and KIT/PDGFRA-wild type cases from therapy without any further selection. Median follow-up time was 27 months. RESULTS: The most common primary localization of GIST was small bowel (63 patients; 59%), followed by the stomach (40 patients; 37%). The majority of GIST cases harboured exon 11 KIT mutations (88 cases, 82%), 11 cases had exon 9 KIT mutations (10%), 8 had other KIT/PDGFRA mutations potentially sensitive to imatinib. Forty patients (37%) finished 3-year adjuvant imatinib therapy as planned, 48 (45%) still continue therapy, 5 (4.5%) patients had finished adjuvant therapy prematurely due to toxicity, 6 (6%) due to disease progression on treatment and 8 (7.5%) due to other reasons. The disease relapse was detected in 19 patients, of them in 5 cases in exon 9 KIT mutants (45%), and 14 cases in patients with exon 11 KIT mutations (11%) [p < 0.01]. Estimated 4-year relapse-free survival (RFS) rate is 78%. CONCLUSIONS: The early results of adjuvant therapy with imatinib in routine practice outside clinical trials in high-risk mutation-driven GIST patients only confirm high efficacy of this therapy with better tolerability than in clinical trials. We found overrepresentation of exon 9 KIT mutants and ruptured tumors in a group of patients with disease relapse.

The Long-Term Outcomes of Intensive Combined Therapy of Adult Patients with Localised Synovial Sarcoma.

INTRODUCTION: Synovial sarcoma (SaSy) is a high-grade, malignant soft tissue sarcoma (STS) accounting for 5-9% of STS. The aim of this study was to analyse outcomes of patients with localised SaSy treated in a single institution with a uniform neo- and adjuvant-combined therapy protocol. METHODS: 171 patients with stage II/III SaSy were treated between 1997 and 2014. Chemotherapy consisted of 4 cycles of ifosfamide 12 g/m2 and two cycles of a doxorubicin-based regimen 75 mg/m2. With the exception of patients who underwent amputation, all patients received neoadjuvant radiotherapy. RESULTS: Median age was 33 years (range 17-69). Tumours larger than 5 cm in size were found in 70% of patients. The 5-year overall survival (OS), local relapse-free survival (LRFS) and metastasis-free survival (MFS) rates were 75%, 80% and 60%, respectively. In multivariate Cox's regression, age > 35 years, male sex, larger tumour size and histology other than monophasic were associated with worse OS. CONCLUSIONS: In adult patients with localised SaSy, long-term survival can be achieved in a significant proportion of cases with intensive combined therapy. The multivariate analysis identified age, sex, disease stage and histology subtype as independent prognostic factors of OS.

Systemic Treatment for Advanced and Metastatic Malignant Peripheral Nerve Sheath Tumors-A Sarcoma Reference Center Experience.

Malignant peripheral nerve sheath tumor (MPNST) is a rare type of soft tissue sarcomas. The localized disease is usually treated with surgery along with perioperative chemo- or radiotherapy. However, up to 70% of patients can develop distant metastases. The study aimed to evaluate the modes and outcomes of systemic treatment of patients with diagnosed MPNST treated in a reference center. In total, 115 patients (56 female and 59 male) diagnosed with MPNST and treated due to unresectable or metastatic disease during 2000-2019 were included in the retrospective analysis. Schemes of systemic therapy and the outcomes-progression-free survival (PFS) and overall survival (OS)-were evaluated. The median PFS in the first line was 3.9 months (95% CI 2.5-5.4). Doxorubicin-based regimens were the most commonly used in the first line (50.4% of patients). There were no significant differences in PFS between chemotherapy regimens most commonly used in the first line (p = 0.111). The median OS was 15.0 months (95% CI 11.0-19.0) and the one-year OS rate was 63%. MPNST are resistant to the majority of systemic therapies, resulting in poor survival in advanced settings. Chemotherapy with doxorubicin and ifosfamide is associated with the best response and longest PFS. Future studies and the development of novel treatment options are necessary for the improvement of treatment outcomes.

Malignant peripheral nerve sheath tumors - Outcomes and prognostic factors based on the reference center experience.

INTRODUCTION: Malignant peripheral nerve sheath tumor (MPNST) accounts for about 5% of soft tissue sarcomas. It can occur as sporadic diseases or can be associated with type 1 neurofibromatosis. MPNST is usually associated with poor prognosis, mostly due to their aggressive behavior, high metastatic potential, and resistance to chemotherapy. Our study aimed to determine treatment outcomes and associated prognostic factors in a large cohort of patients with MPNSTs treated at the reference sarcoma center. METHODS: 239 consecutive patients (114 women and 125 men) diagnosed with MPNST between March 1998 and March 2018 who were treated with surgery with curative intent in the reference sarcoma center were included in the retrospective analysis. RESULTS: The mean age at diagnosis was 51 years (range 15-86). 28 (11.7%) patients had neurofibromatosis type 1 associated tumors (NF1 positive). Median OS was 126.5 months and 5-year survival rate was 61.9% in the group treated with curative intent. Median DFS, LRFS and DMFS were 91.6, 126.5 and 126.5 months, respectively. We identified tumor size, high tumor grade and positive surgical margins as independent negative predictors of DFS, LRFS, DMFS and OS. CONCLUSIONS: High-quality surgery remains a gold standard of MPNST treatment. High grade, size and quality of surgery are significant independent prognostic factors for overall survival. There is an unmet need for improvement, especially regarding the perioperative treatment and treatment of metastatic disease. Future studies on the biology of MPNST would lead to the development of novel treatment options and improvement of treatment outcomes.

Hypofractionated Radiotherapy in Locally Advanced Myxoid Liposarcomas of Extremities or Trunk Wall: Results of a Single-Arm Prospective Clinical Trial.

INTRODUCTION: Myxoid liposarcoma (MLPS) has been reported to be more radiosensitive compared with other soft tissue sarcomas. The main objective of the study was to assess the efficacy of hypofractionated radiotherapy (RT) in the preoperative setting in patients with locally advanced primary MLPS. METHODS: Single-arm prospective exploratory clinical trial enrolled MLPS patients for preoperative 5 × 5 Gy RT with delayed surgery. The endpoints of the study were the rate of early wound healing complications and 5-year local control rate. RESULTS: 29 patients (pts) were included, all had tumors located on the lower limb. The median maximum size of the tumor was 13 cm (IQR 10-15 cm). Early RT tolerance was good. Postoperative wound complications occurred in 11 pts (37.9%), late complications concerned 13.8% of patients. A total of 27 patients were included for the efficacy analyses. The pathological features of response to RT were detected in all analyzed surgical specimens. In 25 patients R0 margins were achieved, two patients had an R1 resection. None of the patients had local recurrence. CONCLUSION: Preoperative hypofractionated RT with a prolonged gap between RT and surgery is a feasible method of the management of MLPS, providing a good local control and low rates of treatment toxicity.