Localized Soft Tissue Sarcoma Research Articles

Neoadjuvant pazopanib with radiation therapy in patients with localized sarcoma: Experience from a sarcoma center.

e23555 Background: Tissue oxygenation is critical to the success of radiation therapy (RT) in any tumor type. However, tumor vasculature is abnormally structured and dysfunctional. Anti-angiogenic molecules have been shown to stabilize the intratumoral vascular structures and improve tissue oxygenation, which may aid in the success of RT. Pazopanib (PAZO) is a multi-kinase inhibitor targeting the Vascular Endothelial Growth Factor Receptor. Here, we report the pathologic outcome and clinical correlates of concurrent use of neoadjuvant PAZO and RT in our cohort of patients with localized soft-tissue sarcoma (STS). Methods: This is a retrospective, single institution study of patients diagnosed with localized STS between January 2019 and October 2023. Patients who received concurrent PAZO and pre-operative external beam RT (50 Gy in 25 fractions) were included. Patients with metastatic disease, unplanned resections, and those requiring excisional biopsy/curettage for diagnosis were excluded. The primary endpoint was the rate of major pathologic response (mPR) defined by > 90% necrosis on surgical pathology specimen. The secondary endpoint was local relapse-free survival (RFS), distant metastasis-free survival (DMFS), and local and distant relapse rate (RR) at 6 months. All-grade toxicities from PAZO were recorded. Results: Ten patients with a median age of 51 years (Interquartile range (IQR): 34-76) were included. Undifferentiated pleomorphic sarcoma was the most common histologic subtype (50% patients). Median follow up was 24.2 months (IQR: 11-36). Six patients tolerated the maximum dose of PAZO until RT completion (800mg PO daily). The dose of PAZO was reduced in 4 patients due to grade 3 GI toxicity and HTN. Nine patients stayed on PAZO until RT completion. The median time to surgery after RT was 42 days (IQR: 37-77). The median largest tumor dimension prior to RT was 11.65 cm (IQR: 3.8 to 18), and 10.6 cm (IQR: 5.4 to 19.7) after RT completion. Nine of 10 patients had R0 resection, and 7 (70%) had mPR. Three of 7 (43%) patients had complete necrosis. All patients with R0 resection have no local recurrence after a median follow-up of 23 months (IQR: 11-36). Median local RFS was 20 months (IQR: 5-32), and DMFS was 6 months (IQR: 1-32). The local RR at 6 months was 10%, and the distant RR at 6 months was 30%. No correlation was observed between mPR and DMFS. Conclusions: Historically, neoadjuvant RT alone induces a mPR in ~30% of patients with localized STS. In our cohort, neoadjuvant PAZO with RT achieved an mPR in 70% of patients. Although dose reduction and grade 3 toxicity were noted in the majority of patients, these were reversible after stopping PAZO. There was no correlation between mPR and DMFS. However, a short course of PAZO with RT may help achieve R0 margins, which is the strongest predictor of better local RFS. A randomized trial is warranted to help understand the true impact of neoadjuvant PAZO with RT.

Randomized phase III trial of neo-adjuvant and adjuvant chemotherapy vs adjuvant chemotherapy alone for localized soft tissue sarcoma (NACLESS, JCOG2102).

TPS11589 Background: Soft-tissue sarcomas (STS) are a rare malignant tumor. Adjuvant perioperative chemotherapy has been investigated for high-risk patients due to the poor overall survival (OS) for surgery. A meta-analysis revealed that adjuvant chemotherapy (AC) with doxorubicin plus ifosfamide (AI) significantly prolonged OS with an absolute risk reduction of 11%. However, the optimal timing for surgery and number of courses of chemotherapy are still controversial. In Europe, Italian sarcoma group and the Spanish sarcoma group reported on the non-inferiority of three courses of neoadjuvant chemotherapy (NAC) + surgery without AC, compared to three courses of NAC + surgery + two courses of AC. On the other hand, even in the same Europe, the latest report on perioperative chemotherapy with AI from Germany was a trial of surgery + AC. Furthermore, adjuvant chemotherapy itself remains skeptical in other countries such as the US, UK, and Canada. No investigation has been made into whether chemotherapy/surgery are better to initiate treatment with. In Japan, the standard treatment is three courses of NAC with AI, surgery, and two of AC with AI. However, in JCOG1306, NAC was discontinued in 12 of 70 (17.1%) patients due to high toxicity. Only one patient (1.4%) became partial response after NAC, whereas six patients (8.6%) had disease progression during NAC. Of the 65 patients eligible for limb-sparing surgery at enrollment, three (4.6%) underwent limb amputation. Upfront surgery followed by three courses of AC was considered the most promising treatment, it avoided extended surgery and reduced toxicity while maintaining an OS equivalent to the standard treatment. The aim of this trial is to optimize the balance between the survival benefit of perioperative chemotherapy, reduce toxicities, and risks of extended surgery. Methods: This is a multicenter two-arm open-label randomized phase III trial. Patients are randomly assigned to standard (three courses of NAC, surgery, and two of AC) or experimental (surgery and three courses of AC) arms with AI comprising doxorubicin (30 mg/m2, days 1, 2) and ifosfamide (2 g/m2, days 1–5). Major inclusion criteria were (1) spindle cell STS; (2) T2-4N0M0 (UICC/AJCC 8th edition) and deeply located; (3) resectable tumors in the extremities or trunk; (4) age, 16–70 years; (5) ECOG performance status of 0–1; (6) no history of chemotherapy/radiotherapy; and (7) sufficient bone marrow function. To evaluates the non-inferiority in OS (margin: hazard ratio of 1.61) with power of 70% and one-sided alpha of 10%, 224 patients will be enrolled from 39 institutions in Japan. We began this study on November 16, 2022, and 27 of 224 patients have been enrolled as of January 7, 2024. Clinical trial information: jRCTs031220446 .

Pathologic complete response in patients with localized soft tissue sarcoma treated with neoadjuvant therapy and its correlation with clinical outcomes: A systematic review.

e23529 Background: Soft tissue sarcomas (STS), comprising approximately 1% of adult solid malignancies, are primarily treated with surgery, with the choice of perioperative treatment being a challenging and highly individualized decision. Clinical trials assessing neoadjuvant modalities in STS predominantly use clinical outcomes or radiologic response as endpoints, with pathologic complete response (pCR) typically not being employed as a designated study endpoint. There is a growing inclination towards neoadjuvant treatment for STS. While pCR serves as a crucial marker guiding treatment decisions in other neoplasms like breast cancer and urothelial cancer, it is not yet used in a similar setting for STS. Our systematic review aimed to assess the rates of pCR in clinical trials of different neoadjuvant modalities for STS and its correlation with patient clinical outcomes. Methods: A systematic literature search was conducted, with eligibility criteria being prospective or retrospective, phase I, II or III trials testing neoadjuvant treatments for STS. Neoadjuvant treatments were chemotherapy, radiotherapy, TKIs or combinations of the above. 23 studies were included, from which data regarding rates of pCR with each treatment, as well as the correlation of pCR with clinical outcomes, were retrieved. Results: Of the 23 trials included, seven did not assess pCR. In the remaining 16 trials, pCR was defined by either ≥90% or ≥95% pathologic necrosis in the tumor specimen. The percentage of patients who achieved pCR ranged from 8 to 58%. Most of these trials did not assess an association between pCR and clinical outcomes. However, among those investigating this correlation, a positive association was identified between pCR and both 5-year disease-specific survival (DSS) and 5-year overall survival (OS). Table 1 summarizes the eight trials that sought to correlate rates of pCR with clinical outcomes. Conclusions: Our findings indicate pCR variability across different neoadjuvant treatments for STS and a possible positive correlation with patient outcomes. Consequently, we propose considering pCR as a surrogate endpoint in future prospective trials for STS that might guide further treatment decisions. [Table: see text]

Amputation in patients with extremity soft tissue sarcoma: the experience of an East Asian referral center

BackgroundThis study aimed to investigate the characteristics and clinical outcomes in a series of patients with extremity soft tissue sarcoma (STS) who underwent amputation at a large East Asian referral center.Patients and methodsOf the 652 patients who underwent surgery for extremity STS, data of 37 consecutive patients who underwent amputation were reviewed retrospectively. The median follow-up period was 96.0 months (range, 15–216). The patients were classified in to three cohorts. The primary localized (PL) group included patients who underwent amputation as a primary surgical procedure with curative intent. The recurrent localized (RL) group included patients who underwent amputation as a revision procedure after failure of previous limb sparing surgeries. The metastatic group included patients who underwent amputation as a palliative procedure.ResultsThere were 22 cases of amputation in 596 STS patients and the amputation rate was 3.6% (22/596). Further, 1.8% (9/490) of patients with primary localized STS underwent amputation. Patients with localized STS who underwent amputation had a 5-year disease-specific survival (DSS) rate of 89.9% (95% Confidence Interval (CI), 87.1–92.7%), a local-recurrence-free survival (LRFS) of 84.1% (95% CI, 80.5–87.6%), and a metastasis-free survival (MFS) of 84.6%. (95% CI, 81.1–88.0%) Compared with previous studies, our results showed higher DSS and MFS rates with similar LRFS.ConclusionsThe amputation rate of extremity STS in our institute in East Asia was similar but slightly lower than that reported in Western studies. The oncologic outcome of amputation reported in this study was higher than that indicated in Western studies and oncologic outcome of amputation was not statistically different from those of limb salvage surgery. However, considering the small cohort in single institute study, there is a possibility of selection bias and future multi-center study is necessary. From our results, amputation is still a feasible option for appropriately selected patients unsuitable for limb-conserving surgery.

Cardiac Morbidity and Mortality in Patients with Sarcoma: A Population-Based Study.

Soft tissue sarcoma (STS) is a rare malignancy that affects soft tissues. It encompasses various subtypes and requires different treatment strategies. Doxorubicin is a commonly used anthracycline in the management of localized and metastatic STS. However, high doses of doxorubicin are associated with cardiotoxicity, which can significantly impact patients' long-term outcomes. This study aimed to evaluate doxorubicin's effect on cardiac function in patients with sarcoma and to correlate the frequency of cardiotoxicity with potential risk factors. A retrospective analysis was conducted on patients with sarcoma who were treated with doxorubicin between 2016 and 2022 at King Abdulaziz Medical City in Saudi Arabia. Patient demographic information, comorbidities, cardiac measurements, laboratory values, systemic therapy, and treatment outcomes were collected from electronic medical records. A statistical analysis was performed to assess the association between cardiotoxicity and various factors. A total of 133 patients were included in the study, with a median age of 30 years. Cardiotoxicity was observed in 9% of the patients. Female patients had a significantly higher risk of developing cardiotoxicity. Patients with a higher Eastern Cooperative Oncology Group (ECOG) performance status and lower troponin I levels also had an increased risk of cardiotoxicity. However, there was no significant association between cardiotoxicity and the number of chemotherapy cycles, total cumulative dose of doxorubicin, or history of radiation. Furthermore, patients with cardiotoxicity had a higher risk of mortality. The overall survival of the patients was 18 months. Doxorubicin-associated cardiotoxicity is a concern for patients with sarcoma. Female patients and patients with a higher ECOG performance status are at an increased risk of developing cardiotoxicity. Careful monitoring and risk assessment are crucial for mitigating the adverse effects of doxorubicin treatment in patients with sarcoma. Future studies are warranted to validate these findings and explore preventive strategies for doxorubicin-induced cardiotoxicity in patients with sarcoma.

Neoadjuvant Radiotherapy Is Associated with Fewer Acute Adverse Skin Reactions Without Increased Risk of Postoperative Wound Complications in High-Grade Extremity Soft Tissue Sarcoma - A Retrospective Comparative Study with A Mean Follow-Up of 7 Years

Aim: In this study, we aim to compare the adverse effects and oncological outcomes of patients with high-grade extremity soft tissue sarcoma receiving neoadjuvant or adjuvant RT. Methods: From 2008 to 2022, Sixty-four patients underwent limb-preserving surgery in our institute for localized high-grade extremity soft tissue sarcoma were included. Thirty-nine patients received adjuvant radiotherapy while twenty-five patients received neoadjuvant RT before surgery if the soft tissue sarcomas were close to the neurovascular bundles, bones or histological types of myxoid liposarcoma or rhabdomyosarcoma. Primary outcomes were acute RT-related skin adverse reactions and significant side effects comprising postoperative wound complications, pathological fractures and RT-induced sarcoma. Secondary outcomes included surgical margin quality, Local-Recurrence (LR)-free survival, metastasis-free survival and overall survivorship. Results and Discussion: Patients in the neoadjuvant RT group had significantly fewer acute RT-induced adverse skin reactions than the adjuvant RT group (p=0.044, Table 2). None in the neoadjuvant RT group suffered severe acute skin reaction (RTOG grade 3-4). Wound infection (n=2) and pathological fracture (n=1) were rare in both adjuvant and neoadjuvant RT groups (P=0.640 & 1.000 respectively). Survival curves for local-recurrence-free survival, metastasis-free survival and overall survivorship of both neoadjuvant and adjuvant groups were analyzed via Kaplan-Meier Curve. All results are statistically insignificant, with p=0.835, 0.948 and 0.540, respectively. Presence of metastasis was the only statistically significant predictor of the overall survival-adjusted hazard ratio of 8.7 (95%CI 2.7-28), p<0.001. Conclusion: Patients with neoadjuvant RT had lower cumulative radiation doses and fewer acute adverse skin reactions. There was no increased risk of postoperative wound complication compared to adjuvant RT. The LR-free survival, metastasis-free survival and overall survival were comparable in both groups. Our results suggested that postponing surgery to eight weeks after neoadjuvant RT and primary wound closure were associated with fewer wound complications, but further studies were warranted.

Non-invasive monitoring of neoadjuvant radiation therapy response in soft tissue sarcomas by multiparametric MRI and quantification of circulating tumor DNA-A study protocol.

Wide resection remains the cornerstone of localized soft-tissue sarcomas (STS) treatment. Neoadjuvant radiation therapy (NRT) may decrease the risk of local recurrences; however, its effectiveness for different histological STS subtypes has not been systematically investigated. The proposed prospective study evaluates the NRT response in STS using liquid biopsies and the correlation of multiparametric magnetic resonance imaging (mpMRI) with histopathology and immunohistochemistry. Patients with localized high-grade STS, who qualify for NRT, are included in this study. Quantification of circulating tumor DNA (ctDNA) in patient blood samples is performed by targeted next-generation sequencing. Soft-tissue sarcoma subtype-specific panel sequencing in combination with patient-specific exome sequencing allows the detection of individual structural variants and point mutations. Circulating free DNA is isolated from peritherapeutically collected patient plasma samples and ctDNA quantified therein. Identification of breakpoints is carried out using FACTERA. Bioinformatic analysis is performed using samtools, picard, fgbio, and the MIRACUM Pipeline. Combination of conventional MRI sequences with diffusion-weighted imaging, intravoxel-incoherent motion, and dynamic contrast enhancement. Multiparametric MRI is performed before, during, and after NRT. We aim to correlate mpMRI data with the resected specimen's macroscopical, histological, and immunohistochemical findings. Preliminary data support the notion that quantification of ctDNA in combination with tumor mass characterization through co-registration of mpMRI and histopathology can predict NRT response of STS. The methods presented in this prospective study are necessary to assess therapy response in heterogeneous tumors and lay the foundation of future patient- and tumor-specific therapy concepts. These methods can be applied to various tumor entities. Thus, the participation and support of a wider group of oncologic surgeons are needed to validate these findings on a larger patient cohort.

Radiomics Model for Predicting Pulmonary Metastasis in Sarcoma Patients

The lung is the most common site of metastasis in localized extremity soft tissue sarcomas (STS). Indeterminant lung nodules leads to challenges for both patients and providers. As such, accuracy in the diagnosis of pulmonary metastasis (PM) is important for clinical decision making. The purpose of this is study is to develop and evaluate a CT-based radiomic model to predict PM in sarcoma patients with indeterminate pulmonary nodules. Fifty-seven stage I-III sarcoma patients with indeterminate lung nodules on unenhanced CT that were approved for this study by our institution's internal review board (IRB). Twenty-two developed and categorized as PM and 35 without PM. A total number of 322 indeterminate nodules were investigated, where 165 & 157 nodules were from patients with and without PM, respectively. A total of 96 radiomic features (RF) (including first order statistics, 2d shape features, gray level co-occurrence, gray level size zone, gray level run length, neighboring gray tone difference & gray level dependence matrices) were taken from unenhanced CT images of each patient. We included 2D shape features since the size and shape of indeterminate lung nodules may have some correlation with PM. Spearman correlation were used to rule out redundant features (r2>0.9). T-test statistics was used to determine feature with significant differences that can differentiate responders with and without PM. Support Vector Machine (SVM) model was fitted to combinations of groups of 2-3 radiomic features. The AUC of the ROC curve was used to evaluate the model performance. Pointwise confidence intervals (CI) for AUC were calculated using 100 bootstrap replicates. Four features were found significant after Spearman correlation and T-test statistical testing: 1. Maximum (MAX); 2. Minor Axis Length (MAL); 3. Gray Level Non-uniformity (GLNU); and 4. Interquartile Range (IR). The best performing 2-feature radiomic SVM model had an AUC of 0.69 (95% CI 0.61,0.74) for the MAX and GLNU features. The best performing 3-feature radiomic SVM model had an AUC of 0.74 (95% CI 0.70,0.80) for the MAX, MAL and IR features. CT-based radiomics model has the potential to be used to predict PM in sarcoma patients presenting with indeterminate lung nodules. Additional research will focus on investigating derived parameters for existing RF, such as the ratio of the max RF to mean RF, to see if they improve the predictive performance of the model, as well as testing the models on external patient cohort. These radiomic models could be useful tools in guiding PM screening and providing a patient specific monitoring of sarcoma patients.

Oncology

The August 2023 Oncology Roundup360 looks at: Giant cell tumour of bone with secondary aneurysmal bone cyst does not have a higher risk of local recurrence; Is bone marrow aspiration and biopsy helpful in initial staging of extraskeletal Ewing’s sarcoma?; Treatment outcomes of extraskeletal Ewing’s sarcoma; Pathological complete response and clinical outcomes in patients with localized soft-tissue sarcoma treated with neoadjuvant chemoradiotherapy or radiotherapy; Long-term follow-up of patients with low-grade chondrosarcoma in the appendicular skeleton treated by extended curettage and liquid nitrogen; Cancer-specific survival after limb salvage versus amputation in osteosarcoma; Outcome after surgical treatment of dermatofibrosarcoma protuberans: does it require extensive follow-up, and what is an adequate resection margin?; Management of giant cell tumours of the distal radius: a systematic review and meta-analysis.

Photon and Proton irradiation in Patient-derived, Three-Dimensional Soft Tissue Sarcoma Models

BackgroundDespite their heterogeneity, the current standard preoperative radiotherapy regimen for localized high-grade soft tissue sarcoma (STS) follows a one fits all approach for all STS subtypes. Sarcoma patient-derived three-dimensional cell culture models represent an innovative tool to overcome challenges in clinical research enabling reproducible subtype-specific research on STS. In this pilot study, we present our methodology and preliminary results using STS patient-derived 3D cell cultures that were exposed to different doses of photon and proton radiation. Our aim was: (i) to establish a reproducible method for irradiation of STS patient-derived 3D cell cultures and (ii) to explore the differences in tumor cell viability of two different STS subtypes exposed to increasing doses of photon and proton radiation at different time points.MethodsTwo patient-derived cell cultures of untreated localized high-grade STS (an undifferentiated pleomorphic sarcoma (UPS) and a pleomorphic liposarcoma (PLS)) were exposed to a single fraction of photon or proton irradiation using doses of 0 Gy (sham irradiation), 2 Gy, 4 Gy, 8 Gy and 16 Gy. Cell viability was measured and compared to sham irradiation at two different time points (four and eight days after irradiation).ResultsThe proportion of viable tumor cells four days after photon irradiation for UPS vs. PLS were significantly different with 85% vs. 65% (4 Gy), 80% vs. 50% (8 Gy) and 70% vs. 35% (16 Gy). Proton irradiation led to similar diverging viability curves between UPS vs. PLS four days after irradiation with 90% vs. 75% (4 Gy), 85% vs. 45% (8 Gy) and 80% vs. 35% (16 Gy). Photon and proton radiation displayed only minor differences in cell-killing properties within each cell culture (UPS and PLS). The cell-killing effect of radiation sustained at eight days after irradiation in both cell cultures.ConclusionsPronounced differences in radiosensitivity are evident among UPS and PLS 3D patient-derived sarcoma cell cultures which may reflect the clinical heterogeneity. Photon and proton radiation showed similar dose-dependent cell-killing effectiveness in both 3D cell cultures. Patient-derived 3D STS cell cultures may represent a valuable tool to enable translational studies towards individualized subtype-specific radiotherapy in patients with STS.

Molecular residual disease (MRD) detection using bespoke circulating tumor DNA (ctDNA) assays in localized soft tissue sarcoma (STS).

11509 Background: Surgery and (neo)adjuvant radiotherapy (RT) are the mainstay curative treatments for localized STS. Despite treatment, up to 50% of STS patients experience metastatic relapse, and routine use of adjuvant systemic therapy (AST) remains controversial. The presence of ctDNA following curative-intent treatment of STS is a potential biomarker for MRD and may identify patients who are likely to benefit from AST. Given the genomic heterogeneity of STS, a histology-agnostic approach to ctDNA detection in this population is desirable. Methods: Patients (pts) with localized, high risk (size ≥ 5cm, grade ≥ 2) STS were enrolled prior to (neo)adjuvant RT and surgery. Pts who received (neo)adjuvant systemic treatment were excluded. Blood samples for ctDNA analysis were collected at diagnosis, post-RT, post-surgery and every 3 months for up to 2 years. Whole exome sequencing (WES) of archival tumor and matched normal were carried out to identify patient-specific, somatic, single nucleotide variants. Personalized and tumor-informed, multiplex PCR next generation sequencing-based ctDNA (Signatera) assays were then developed to track ctDNA in serially collected plasma samples. ctDNA levels were expressed as mean tumor molecules per milliliter (MTM/ml) of plasma. Radiologic surveillance was performed every 3 months following surgery. The primary endpoint was a ctDNA detection rate of >70% at diagnosis. Secondary endpoints included MRD detection after local therapy and correlation of ctDNA levels with disease relapse. Results: A total of 140 plasma samples from 22 pts [18 male and 4 female; median age: 65 years, range: 30 – 84] were obtained. RT was preoperative in 19/22 pts. Of the 22 tumor samples, 20 had adequate tissue quality for WES to enable ctDNA assay design. Tumor histologic subtypes included undifferentiated pleomorphic sarcoma (n = 6), myxofibrosarcoma (n = 5), and liposarcoma (n = 9). A median of 7 plasma samples per patient (range: 2 – 10) were analyzed. ctDNA was detected in 80% of pts (16/20) at diagnosis, with median ctDNA level of 3.4 MTM/mL (range: 0.2 – 1393.9). Of these 16 pts, 15 (94%) became ctDNA negative at the immediate post-surgical timepoint. In addition, ctDNA was detected in 4 pts (80%) prior to or around radiologic relapse with a median lead time of 92 days. Conclusions: Personalized, tumor-informed ctDNA assays can detect MRD after definitive local therapy and/or prior to radiologic recurrence in patients with localized high-risk STS. As such, serial ctDNA monitoring provides prognostic value and may further identify patients that will benefit from AST treatment. Additional studies evaluating ctDNA as a predictive biomarker for AST benefit are ongoing.

Multidisciplinary approach for a high-risk, localized soft tissue sarcoma of the trunk after unplanned nononcological resection.

Multidisciplinary approach for a high-risk, localized soft tissue sarcoma of the trunk after unplanned nononcological resection.

Pathologic Complete Response and Clinical Outcomes in Patients With Localized Soft Tissue Sarcoma Treated With Neoadjuvant Chemoradiotherapy or Radiotherapy

Pathologic complete response (pCR) may be associated with prognosis in patients with soft tissue sarcoma (STS). We sought to determine the prognostic significance of pCR on survival outcomes in STS for patients receiving neoadjuvant chemoradiotherapy (CT-RT) (Radiation Therapy Oncology Group [RTOG] 9514) or preoperative image-guided radiotherapy alone (RT, RTOG 0630) and provide a long-term update of RTOG 0630. RTOG has completed 2 multi-institutional, nonrandomized phase 2 clinical trials for patients with localized STS. One hundred forty-three eligible patients from RTOG 0630 (n = 79) and RTOG 9514 (n = 64) were included in this ancillary analysis of pCR and 79 patients from RTOG 0630 were evaluated for long-term outcomes. Patients in trial 9514 received CT interdigitated with RT, whereas those in trial 0630 received preoperative RT alone. Overall and disease-free survival (OS and DFS) rates were estimated by the Kaplan-Meier method. Hazard ratios (HRs) and P values were estimated by multivariable Cox model stratified by study, where possible; otherwise, P values were calculated by stratified log-rank test. Analysis took place between December 14, 2016, to April 13, 2017. Overall there were 42 (53.2%) men; 68 (86.1%) were white; with a mean (SD) age of 59.6 (14.5) years. For RTOG 0630, at median follow-up of 6.0 years, there was 1 new in-field recurrence and 1 new distant failure since the initial report. From both studies, 123 patients were evaluable for pCR: 14 of 51 (27.5%) in trial 9514 and 14 of 72 (19.4%) in trial 0630 had pCR. Five-year OS was 100% for patients with pCR vs 76.5% (95% CI, 62.3%-90.8%) and 56.4% (95% CI, 43.3%-69.5%) for patients with less than pCR in trials 9514 and 0630, respectively. Overall, pCR was associated with improved OS (P = .01) and DFS (HR, 4.91; 95% CI, 1.51-15.93; P = .008) relative to less than pCR. Five-year local failure rate was 0% in patients with pCR vs 11.7% (95% CI, 3.6%-25.1%) and 9.1% (95% CI, 3.3%-18.5%) for patients with less than pCR in 9514 and 0630, respectively. Histologic types other than leiomyosarcoma, liposarcoma, and myxofibrosarcoma were associated with worse OS (HR, 2.24; 95% CI, 1.12-4.45). This ancillary analysis of 2 nonrandomized clinical trials found that pCR was associated with improved survival in patients with STS and should be considered as a prognostic factor of clinical outcomes for future studies. ClinicalTrials.gov Identifiers: RTOG 0630 (NCT00589121); RTOG 9514 (NCT00002791).

Patterns of Failure in High-Grade Soft Tissue Sarcomas of the Extremities and Trunk Wall After Pre- or Postoperative Radiation Therapy

Radiotherapy (RT) is a mainstay of treatment for high-grade soft tissue sarcomas (STS). We sought to examine the pattern of local recurrence (LR) with regard to target volume, clinical course, and tumor characteristics in extremity and trunk wall STS patients receiving pre- or postoperative RT. In this retrospective study, LR rates and patterns in 91 adult patients with a primary diagnosis of localized high-grade STS of the extremities and trunk wall treated with pre- or postoperative RT at our institution between 2004 and 2021 were analyzed. Radiation treatment plans and imaging data sets at diagnosis and LR were compared. Seventeen out of 91 (18.7 %) patients developed a LR after a median time of 12.7 months. In 10 out of 13 LRs (76.9%) with available treatment plans and radiographic imaging data at the time of recurrence, the LR occurred within the planned target volume (PTV), 2 LRs were marginal (15.4%, at the edge of the PTV volume), and one relapsed out-of-field (7.7%, outside the PTV volume). Positive surgical margins (microscopic or macroscopic) were found in 5 out of 91 patients (5.5%), 1 of which was found in the 17 patients with LRs (5.9%). Eleven of 13 LR patients (84.6%) with available treatment plans and radiographic imaging data received postoperative RT; the median total RT dose was 60 Gy. Volumetric-modulated arc therapy was used in 10 (76.9%), intensity-modulated RT in 2 (15.4%), and 3-dimensional conformal radiation therapy in 1 (7.7%) of 13 LRs. The majority of LRs occurred within the PTV suggesting that LR is most likely not a consequence of inadequate target volume definition, but rather of radioresistant tumor biology. To further improve local tumor control, future research on the potential of dose escalation with normal tissue sparing, STS subtype-specific tumor biology, radiosensitivity, and surgical technique is indicated.

Amputation surgery associated with shortened survival in patients with localized soft tissue sarcoma

BackgroundThe objectives of this study were to clarify whether localized extremity soft tissue sarcoma (STS) patients who underwent amputation surgery experienced worsened survival and to identify those patients for whom amputation surgery worsened survival. MethodsUsing the Surveillance, Epidemiology, and End Results database, we identified 8897 patients with localized extremity STS between 1983 and 2016. Of these 6431 patients, 733 patients underwent amputation surgery (Amputation group), and 5698 underwent limb-sparing surgery (Limb-sparing group). ResultsAfter adjusting for patient background by propensity score matching, a total of 1346 patients were included. Patients in the Amputation group showed worsened survival (cancer-specific survival (CSS): hazard ratio (HR) = 1.42, 95% confidence interval (CI) 1.15–1.75, overall survival (OS): HR = 1.41, 95%CI 1.20–1.65). In subclass analysis, patients with high-grade STS, spindle cell sarcoma and liposarcoma in the Amputation group showed shortened survival (high-grade–CSS: HR = 1.44, 95%CI 1.16–1.77, OS: HR = 1.38, 95%CI 1.18–1.62; spindle cell sarcoma–CSS: HR = 4.75, 95%CI 1.56–14.4, OS: HR = 2.32, 95%CI 1.45–3.70; liposarcoma–CSS: HR = 2.91, 95%CI 1.54–5.50, OS: HR = 2.32, 95%CI 1.45–3.70). ConclusionsSurvival was shortened in localized extremity STS patients who received amputation surgery.

Non-invasive Monitoring of Soft-tissue Sarcoma Response to Neoadjuvant Radiotherapy by Quantification of Circulating Tumor DNA (ctDNA) and Multiparametric MRI (mpMRI)

Introduction: Soft-tissue sarcomas (STS) are a heterogenous group of rare, yet malignant tumors. Wide resection remains the cornerstone of treatment for localized STS. Current S3 guidelines recommend neoadjuvant radiotherapy for primary, high-grade tumors; however, therapy response for different histological subtypes and gradings has not been systematically investigated. This ongoing prospective study evaluates the response of various STS during the course of neoadjuvant radiotherapy using innovative, non-invasive methods. Through quantification of ctDNA, tumor activity and thus therapy response will be evaluated in correlation with imaging data. Materials and Methods: Liquid biopsies: Detection of circulating tumor DNA (ctDNA) in patient blood samples through targeted next-generation sequencing (NGS). Patient-specific exome sequencing allows the detection of individual structural variants (SVs) and point mutations. Circulating free DNA (cfDNA) is isolated from peritherapeutically collected patient plasma samples and ctDNA quantified therein. Bioinformatic analysis is performed using the MIRACUM Pipeline. Multiparametric MRI (mpMRI): Combination of conventional MRI sequences with diffusion-weighted imaging (DWI) and dynamic contrast enhancement (DCE). Multiparametric MRI is performed before, during, and after neoadjuvant radiotherapy. Accurate co-registration and correlation of mpMRI with the macroscopic, histologic, and immunohistochemical resected specimen allow an analysis of morphological changes during therapy. Results: Quantification of ctDNA mirrors the clinical course and tumor activity. Furthermore, we present imaging markers that allow the characterization of tumor masses for heterogenous STS and the evaluation of therapy response. Conclusion: Liquid biopsies can be used to detect the primary tumor and metastases, and to monitor the course of therapy. Quantification of ctDNA in combination with tumor mass characterization through co-registration of mpMRI and histopathology enables the evaluation of STS response to neoadjuvant radiotherapy. The participation and support of a wider group of oncologic surgeons are needed to validate these findings on a larger patient cohort to create future tumor- and patient-specific therapy concepts.

Correlation of radiological and histopathological response after neoadjuvant radiotherapy in soft tissue sarcoma

Background The aim of this study was to assess the association between radiological and histopathological response after neoadjuvant radiotherapy (nRT) in soft tissue sarcoma (STS), as well as the prognostic value of the different response evaluation methods on the oncological outcome. Methods A retrospective cohort of patients with localized STS of the extremity and trunk wall, treated with nRT followed by resection were included. The radiological response was assessed by RECIST 1.1 (RECIST) and MR-adapted Choi (Choi), histopathologic response was evaluated according to the EORTC-STBSG recommendations. Oncological outcome parameters of interest were local recurrence-free survival (LRFS), disease metastases-free survival (DMFS), and overall survival (OS). Results For 107 patients, complete pre- and postoperative pathology and imaging datasets were available. Most tumors were high-grade (77%) and the most common histological subtypes were undifferentiated pleomorphic sarcoma/not otherwise specified (UPS/NOS, 40%), myxoid liposarcoma (MLS, 21%) and myxofibrosarcoma (MFS, 16%). When comparing RECIST to Choi, the response was differently categorized in 58%, with a higher response rate (CR + PR) with Choi. Radiological responders showed a significant lower median percentage of viable cells (RECIST p = .050, Choi p = .015) and necrosis (RECIST p < .001), and a higher median percentage of fibrosis (RECIST p = .005, Choi p = .008), compared to radiological non-responders (SD + PD). RECIST, Choi, fibrosis, and viable cells were not significantly associated with altered oncological outcome, more necrosis was associated with poorer OS (p = .038). Conclusion RECIST, Choi and the EORTC-STBSG response score show incongruent results in response evaluation. The radiological response was significantly correlated with a lower percentage of viable cells and necrosis, but a higher percentage of fibrosis. Apart from necrosis, radiological nor other histopathological parameters were associated with oncologic outcomes.

Postoperative complications and oncologic outcomes after multimodal therapy of localized high risk soft tissue sarcoma

BackgroundStandard therapy for localized high-risk soft tissue sarcoma includes surgical resection and neoadjuvant or adjuvant radiation therapy (± chemotherapy and locoregional hyperthermia). No difference in oncologic outcomes for patients treated with neoadjuvant and adjuvant radiation therapy was reported, whereas side effect profiles differ. The aim of this analysis was to analyse oncologic outcomes and postoperative complications in patients treated with multimodal treatment.MethodsOncologic outcomes and major wound complications (MWC, subclassified as wound healing disorder, infection, abscess, fistula, seroma and hematoma) were evaluated in 74 patients with localized high-risk soft tissue sarcoma of extremities and trunk undergoing multimodal treatment, and also separately for the subgroup of lower extremity tumors. Clinical factors and treatment modalities (especially neoadjuvant vs. adjuvant radiotherapy) were evaluated regarding their prognostic value and impact on postoperative wound complications.ResultsOncologic outcomes were dependent on number of high risk features (tumor size, depth to superficial fascia and grading), but not on therapy sequencing (however with higher risk patients in the neoadjuvant group). Different risk factors influenced different subclasses of wound healing complications. Slightly higher MWC-rates were observed in patients treated with neoadjuvant therapy, compared to adjuvant radiotherapy, although only with a trend to statistical significance (31.8% vs. 13.3%, p = 0.059). However, except for wound infections, no significant difference for other subclasses of postoperative complications was observed between neoadjuvant and adjuvant therapy. Diabetes was confirmed as a major risk factor for immune-related wound complications.ConclusionRates of major wound complications in this cohort are comparable to published data, higher rates of wound infections were observed after neoadjuvant radiotherapy. Tumor localization, patient age and diabetes seem to be major risk factors. The number of risk factors for high risk soft tissue sarcoma seem to influence DMFS. Neoadjuvant treatment increases the risk only for wound infection treated with oral or intravenous antibiotic therapy and appears to be a safe option at an experienced tertiary center in absence of other risk factors.

Targeted therapies for soft tissue sarcomas and desmoid tumors

Soft tissue sarcomas are a group of rare malignant tumors with a high recurrence and mortality rate. Little progress has been made in the treatment of this pathology over the past decades. Surgery with or without adjuvant/neoadjuvant radiotherapy is still the first-line therapy for localized soft tissue sarcomas, and chemotherapy is an additional option for high-risk patients. However, not all patients with advanced or metastatic soft tissue sarcomas benefit from conventional chemotherapy. Soft tissue sarcomas are characterized by high heterogeneity of biological behavior and a variety of genetic mutations, which indicates the perspective of personalized therapy based on tumor histotype, genetic and molecular characteristics, and new small molecule inhibitors of signaling pathways. This article provides an overview of studies on the effectiveness of targeted therapy for the most common soft tissue sarcomas and desmoid tumors.

Surgical Margins in Soft Tissue Sarcoma Management and Corresponding Local and Systemic Recurrence Rates: A Retrospective Study Covering 11 Years and 169 Patients in a Single Institution.

Soft tissue sarcomas (STSs) are a diverse group of rare malignant soft tissue tumors with a high disease burden. Treatment protocols are complex and, to this day, a precise recommendation for the surgical margin width is lacking. The present study aims to analyze the width of the surgical margins in STS resection specimens and analyze them for local and systemic disease-free survival as well as for most frequent histologic STS subtypes. A total of 169 consecutive patients diagnosed and treated in curative intent in our institution following a primary and localized STS of the extremities or trunk from January 2010 to December 2020 were included in this study regardless of age. Our data reveal that low-grade STSs are best controlled locally by a surgical margin ≥2 mm and in this way also preventing distant metastases effectively. Local recurrence-free survival and metastasis-free survival in high-grade STS were improved by intact muscle fascia or periosteum at the margin when compared only to soft tissue. However, the outcome was independent of the surgical margin width, suggesting a close but negative margin may be safe in high-grade STS subtypes with less invasive growth patterns when combined with adjunct radiochemotherapy.