A phase I study on the combination of neoadjuvant radiotherapy plus pazopanib in patients with locally advanced soft tissue sarcoma of the extremities

Dual effects of radiotherapy on tumor microenvironment and its contribution towards the development of resistance to immunotherapy in gastrointestinal and thoracic cancers

Successful clinical methods for tumor elimination include a combination of surgical resection, radiotherapy, and chemotherapy. Radiotherapy is one of the crucial components of the cancer treatment regimens which allow to extend patient life expectancy. Current cutting-edge radiotherapy research is focused on the identification of methods that should increase cancer cell sensitivity to radiation and activate anti-cancer immunity mechanisms. Radiation treatment activates various cells of the tumor microenvironment (TME) and impacts tumor growth, angiogenesis, and anti-cancer immunity. Radiotherapy was shown to regulate signaling and anti-cancer functions of various TME immune and vasculature cell components, including tumor-associated macrophages, dendritic cells, endothelial cells, cancer-associated fibroblasts (CAFs), natural killers, and other T cell subsets. Dual effects of radiation, including metastasis-promoting effects and activation of oxidative stress, have been detected, suggesting that radiotherapy triggers heterogeneous targets. In this review, we critically discuss the activation of TME and angiogenesis during radiotherapy which is used to strengthen the effects of novel immunotherapy. Intracellular, genetic, and epigenetic mechanisms of signaling and clinical manipulations of immune responses and oxidative stress by radiotherapy are accented. Current findings indicate that radiotherapy should be considered as a supporting instrument for immunotherapy to limit the cancer-promoting effects of TME. To increase cancer-free survival rates, it is recommended to combine personalized radiation therapy methods with TME-targeting drugs, including immune checkpoint inhibitors.

Local Therapies for Metastatic Sarcoma: Why, When, and How?

Management of patients with advanced sarcoma has been evolving in recent decades, from a one-fit-all perspective to a more refined, personalized, and multidisciplinary approach. In parallel, the evolution of local therapies (radiotherapy, surgical and interventional radiology techniques) has contributed to the improvement of survival of patients with advanced sarcoma. In this article, we review the evidence regarding local treatments in advanced sarcoma, as well as its integration with systemic therapies, to provide the reader a wider and deeper perspective on the management of patients with metastatic sarcoma.

Neoadjuvant pazopanib in nonrhabdomyosarcoma soft tissue sarcomas (ARST1321): A report of major wound complications from the Children's Oncology Group and NRG Oncology

BACKGROUND AND OBJECTIVES

The impact upon wound healing of targeted molecular therapies, when incorporated into neoadjuvant therapy of soft tissue sarcoma, is largely unknown. Here, we describe wound complications following addition of pazopanib, a tyrosine kinase inhibitor (TKI), to neoadjuvant radiotherapy (RT) +/- chemotherapy for soft tissue sarcoma.

METHODS

Wound complications were evaluated on dose-finding and randomized arms of ARST1321, a phase II/III study incorporating neoadjuvant RT, +/- pazopanib, +/- ifosfamide/doxorubicin (ID) for sarcoma therapy.

RESULTS

Of 85 evaluable patients, 35 (41%) experienced postoperative wound complications. Most (57%) were grade III. Randomization to pazopanib + RT + ID carried a 50% wound complication rate (17/34, with 47% grade III), compared to 22% (5/23) with ID + RT alone. In nonchemotherapy study arms, pazopanib + RT resulted in a 59% wound complication rate versus 25% for those receiving RT alone. Grade III wound complications occurred among 26% (15/58) of all patients receiving pazopanib. Wound complications occurred a median of 35 days postoperatively. Some occurred following diagnostic biopsies and at remote surgical sites.

CONCLUSION

The addition of pazopanib to neoadjuvant chemotherapy and RT resulted in a higher wound complication rate following therapy of soft tissue sarcoma. The rate of grade III complications remained comparable to that reported in contemporary literature.

Long-term outcomes after definitive radiotherapy with modern techniques for unresectable soft tissue sarcoma

INTRODUCTION

The use of definitive radiotherapy (dRT) in unresectable soft-tissue sarcomas (STS) is still controversial and recent data are scarce. We report clinical results of this therapeutic option.

METHODS

We retrospectively included STS patients treated between 2009 and 2020, with dRT for unresectable or with a measurable residual disease after R2 surgery. Response rate, local failure (LF), progression-free survival (PFS) and overall survival (OS) were evaluated.

RESULTS

116 patients with localized/locally advanced STS were treated from 2009 to 2020, with a median age of 71 years (range 18-92). Most tumors were deep-seated (96.6%), grade 2-3 (85.1%), located in the trunk or extremities (74.2%). Helical tomotherapy, volumetric modulated arc therapy, or stereotactic radiotherapy was performed in 39.7%, 19% and 8.6% of patients, respectively. The median equivalent dose in 2 Gy fractions (EQD2) was 60 Gy (IQR 52-65). At first follow-up, 66 (58.9%) and 25 (22%) patients had stable disease and partial response. After a median follow-up of 54.8 months (IQR 40.3-95.4), 3-year LF, PFS and OS were 43.2%, 16.6% and 34%, respectively. Median OS was 21.4 months (95%CI 14-26). The multivariate analysis identified grade 3 and AJCC T3-T4 stage to be associated with both shorter PFS and OS (all p<0.001). Macroscopically incomplete resection and EQD2 ≥64Gy were associated with better OS (p=0.016 and p=0.007). Acute and late severe adverse events occurred in 24 (19.7%) and 5 (4.3%) patients.

CONCLUSION

In unresectable STS patients, definitive modern radiotherapy is a safe and effective treatment yielding long term control in selected patients.

Kinase inhibitors increase individual radiation sensitivity in normal cells of cancer patients

Purpose

Kinase inhibitors (KI) are known to increase radiosensitivity, which can lead to increased risk of side effects. Data about interactions of commonly used KI with ionizing radiation on healthy tissue are rare.

Patients and methods

Freshly drawn blood samples were analyzed using three-color FISH (fluorescence in situ hybridization) to measure individual radiosensitivity via chromosomal aberrations after irradiation (2 Gy). Thresholds of 0.5 and 0.6 breaks/metaphase (B/M) indicate moderate or clearly increased radiosensitivity.

Results

The cohorts consisted of healthy individuals (NEG, n = 219), radiosensitive patients (POS, n = 24), cancer patients (n = 452) and cancer patients during KI therapy (n = 49). In healthy individuals radiosensitivity (≥ 0.6 B/M) was clearly increased in 5% of all cases, while in the radiosensitive cohort 79% were elevated. KI therapy increased the rate of sensitive patients (≥ 0.6 B/M) to 35% significantly compared to 19% in cancer patients without KI (p = 0.014). Increased radiosensitivity of peripheral blood mononuclear cells (PBMCs) among patients occurred in six of seven KI subgroups. The mean B/M values significantly increased during KI therapy (0.47 ± 0.20 B/M without compared to 0.50 ± 0.19 B/M with KI, p = 0.047).

Conclusions

Kinase inhibitors can intensify individual radiosensitivity of PBMCs distinctly in 85% of tested drugs.

Preoperative Radiation for Soft Tissue Sarcomas: How Much Is Needed?

OPINION STATEMENT

Preoperative radiation therapy is an important component of curative treatment for extremity and superficial trunk soft tissue sarcomas. It has traditionally been delivered to a dose of 50 Gy in 2 Gy fractions over 5 weeks. With significant advances in the multidisciplinary approach to soft tissue sarcomas, preoperative radiation therapy may be omitted for certain cases, delivered over a shortened period of time (1-3 weeks), deintensified for myxoid liposarcomas, or combined with systemic therapy to improve the therapeutic ratio. This article reviews the innovative preoperative radiation therapy strategies currently used to treat extremity and superficial trunk soft tissue sarcomas.

Risk factors for the development of local recurrence in extremity soft-tissue sarcoma

INTRODUCTION

Local recurrence (LR) is one of the main pitfalls in surgery for extremities soft tissue sarcoma (eSTS). Achieving clear histopathological margins is the most important factor to reduce the risk of LR, but the ability to do so depends on not only surgical technique but also the interplay between tumor biology, anatomical location and surgical approach. The balance between postoperative morbidity and oncological benefits in reducing the risk of LR needs to be considered.

AREAS COVERED

This review will cover which etiological factors for the development of eSTS lead to an increased risk of LR and discuss histological subtypes that have a high risk of LR and which surgical and neoadjuvant therapeutic strategies can minimize the risk of LR.

EXPERT OPINION

The traditional view that surgical radicality always results in low rates of LR, while marginality alone always leads to high rates of relapse, is outdated. In the modern era of surgical oncology, limb salvage and high-level function after resectional surgery are the key surgical goals. The best results are achieved by combining effective neoadjuvant treatments with planned bespoke oncological operations that consider the biological and anatomical factors of each individual sarcoma.

A phase II study on the neo-adjuvant combination of pazopanib and radiotherapy in patients with high-risk, localized soft tissue sarcoma

PURPOSE

A prior phase I study showed that the neo-adjuvant combination of pazopanib and radiotherapy was well tolerated, and induced promising pathological responses in soft-tissue sarcoma patients. Results of the subsequent prospective, multicenter phase II, PASART-2 trial are presented here, further investigating the efficacy and safety of this combination.

PATIENTS AND METHODS

Patients with high-risk, localized soft-tissue sarcoma received neo-adjuvant radiotherapy, 50 Gy in 25 fractions (PASART-2A) or with a subsequent dose de-escalation to 36 Gy in 18 fractions (PASART-2B). This was combined with 800 mg once daily pazopanib, which started one week before radiotherapy and finished simultaneously. After an interval of 4-8 weeks, surgical resection was performed. The primary endpoint was the rate of pathological complete responses (pCR), defined as ≤5% viable cells.

RESULTS

25 patients were registered in the study, 21 in PASART-2A and 4 in PASART-2B. After central pathology review, the combination treatment led to a pCR in 5 patients (20%). 17 patients (68%) experienced grade 3+ toxicities during neo-adjuvant treatment, of which the most common were alanine aminotransferase (ALT) elevation, aspartate aminotransferase (AST) elevation, and hypertension, all asymptomatic. Grade 3+ acute post-operative toxicities occurred in 5 patients (20%), of which the most common was wound infection. All patients completed the full radiotherapy regimen and underwent surgery. Pazopanib was discontinued before completion in 9 patients (36%), due to elevated ALT and/or AST, and shortly interrupted in 2 patients (8%), due to hypertension.

CONCLUSION

Apart from asymptomatic hepatotoxicity, the study regimen was well tolerated. Although the pre-specified efficacy endpoint (30% pCR) was not met, a more than doubling of historical pCR rates after neo-adjuvant radiotherapy alone was observed, which warrants further investigation.

Intra-Tumoral Pharmacokinetics of Pazopanib in Combination with Radiotherapy in Patients with Non-Metastatic Soft-Tissue Sarcoma

There is a lack of understanding whether plasma levels of anticancer drugs (such as pazopanib) correlate with intra-tumoral levels and whether the plasma compartment is the best surrogate for pharmacokinetic and pharmacodynamic evaluation. Therefore, we aimed to quantify pazopanib concentrations in tumor tissue, to assess the correlation between tumor concentrations and plasma concentrations and between tumor concentrations and efficacy. In this clinical trial, non-metastatic STS patients were treated with neo-adjuvant concurrent radiotherapy and pazopanib. Plasma samples and tumor biopsies were collected, and pazopanib concentrations were measured using liquid chromatography-tandem mass spectrometry. Twenty-four evaluable patients were included. The median pazopanib tumor concentration was 19.2 µg/g (range 0.149-200 µg/g). A modest correlation was found between tumor concentrations and plasma levels of pazopanib (ρ = 0.41, p = 0.049). No correlation was found between tumor concentrations and percentage of viable tumor cells (p > 0.05); however, a trend towards less viable tumor cells in patients with high pazopanib concentrations in tumor tissue was observed in a categorical analysis. Possible explanations for the lack of correlation might be heterogeneity of the tumors and timing of the biopsy procedure.

Patterns of Perioperative Treatment and Survival of Localized, Resected, Intermediate- or High-Grade Soft Tissue Sarcoma: A 2000-2017 Netherlands Cancer Registry Database Analysis

Background

Standard therapy for localized soft tissue sarcoma (STS) is wide, limb-sparing resection. For intermediate- or high-grade tumors, (neo)adjuvant therapies are frequently added to the treatment plan. In this study, data from a Dutch nationwide database are used to (1) assess whether perioperative management of STS follows ESMO guidelines, (2) characterize prognostic factors for overall survival (OS), and (3) assess the association between perioperative treatment and survival.

Methods

All intermediate- or high-grade, localized STS cases, who have undergone surgery and diagnosed between 2000 and 2017, were identified in the Netherlands Cancer Registry (NCR) database. Variables with demographic, treatment, and survival data were obtained. Survival curves were estimated by Kaplan–Meier's method, and the effect of prognostic factors on OS was assessed in a multivariable Cox regression analysis.

Results

A total of 4957 patients were identified. There were slightly more males (54.7%). Median age at diagnosis was 64 years, and 53.6% of the tumors were located in the extremities. Radiotherapy (RT) was administered to 2481 (50.1%) patients, and 252 (5.1%) patients were treated with perioperative systemic chemotherapy. The total use of perioperative RT did not significantly change in the last 20 years, but the timing followed clinical guidelines: preoperative RT increased significantly (2000–2008: 3.7%, 2009–2017: 22.3%; p < 0.001), whereas the use of postoperative RT diminished (2000–2008: 45.9%, 2009–2017: 26.1%; p < 0.001). The use of perioperative chemotherapy slightly decreased (2000–2008: 5.9%, 2009–2017: 4.4%; p = 0.015). 5-year OS was 59.6% (95% CI: 58.2–61.0). Sex, age, year of diagnosis, tumor location, tumor size, histological grade, depth, histological subtype, surgical margins, and the use of perioperative RT were identified as independent predictors for OS.

Conclusion

Preoperative RT is gradually replacing postoperative RT for localized STS in the Netherlands. The use of perioperative chemotherapy is rare and has slightly decreased in recent years. Identified baseline characteristics and treatment factors predicting OS may aid in future treatment decisions.

What is the standard indication of adjuvant or neoadjuvant chemotherapy in localized soft-tissue sarcoma?

PURPOSE OF REVIEW

The aim is to bring latest evidence of the role of perioperative chemotherapy in localized soft-tissue sarcomas (STS) of limbs and to review the risk classification systems of retroperitoneal and extremity STS.

RECENT FINDINGS

High-risk subset of localized STS of limbs and trunk-wall, defined with classic prognostic factors, consistently obtained 5-year overall survival ranging from 69 to 76% in randomized patients treated with full-dose of anthracycline and ifosfamide. Validated nomograms accurately predict, on individual basis, the risk of death and recurrence in localized STS of retroperitoneum and limbs, enabling a better selection of high-risk patients (usually those with death risk of ≥40%) that potentially could benefit with perioperative systemic treatment. Nomograms have virtually converted a negative large perioperative trial into a positive, favouring chemotherapy arm in the high-risk selection.

SUMMARY

Perioperative three cycles of full-dose of anthracycline and ifosfamide should be proposed on an individual basis, in reference sarcoma centres, to high-risk localized STS of limbs or trunk-wall in certain histologies.

The role of radiotherapy in adult soft tissues sarcoma of the extremities

Local management of adult soft tissue sarcoma of the extremities has evolved over the past decades. Until the 1970s, radical surgery (amputations) was the standard therapeutic procedure resulting in significant physical and psychological morbidity for the patients. In the present era, limb sparing surgery combined with radiotherapy represents the current standard of care for high grade and > 5 cm STSs. This approach guarantees high local control rate and function preservation. The aim of this paper is to summarize the current evidence for RT in STSs of the extremities. Outcomes, technical details (techniques, timing, dose, volumes of treatment) and the emerging role of RT in the management of oligometastatic disease will be analysed. Finally, results of the recent clinical trials testing new scenarios in RT of STSs will be described.

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.

Stereotactic radiosurgery as a primary treatment for metastatic skull base alveolar soft part sarcoma: a case report

Alveolar soft part sarcoma (ASPS) is a rare malignancy that typically arises in the trunk or extremities and preferentially metastasises to the brain. Radical resection is generally recommended for cranial metastatic ASPS, but stereotactic radiosurgery (SRS) is a recognised alternative for tumours in surgically challenging locations. Here, we present the case of a 22-year-old female, who underwent SRS and systemic therapy with pazopanib for a metastatic ASPS in the left temporal bone. The tumour was successfully controlled without further intervention over 23 months following SRS, which should be considered for metastatic ASPS when surgical resection is not appropriate.

Anti-Angiogenic Agents in Management of Sarcoma Patients: Overview of Published Trials

We reviewed all fully published clinical trials assessing anti-angiogenic agents in sarcoma patients (last issue, January 13, 2020). Anti-angiogenic macromolecules (e.g., bevacizumab or ombrabulin) provide disappointing results. Many multikinase inhibitors have been assessed with non-randomized phase II trials with limited samples and without stratification according to histological subtypes, therefore interpretation of such trials is very challenging. On the contrary, pazopanib, regorafenib, and sorafenib have been assessed using double-blind placebo-controlled randomized phase II or phase III trials. Compared to placebo, sorafenib demonstrates activity in desmoid-type fibromatosis patients. Based on results of phase 3 trial, pazopanib had obtained approval for treatment of pretreated non-adipocytic soft tissue sarcoma. Regorafenib is currently assessed in several clinical settings and provides significant improvement of progression-free survival in pre-treated non-adipocytic soft tissue sarcoma and in advanced pretreated osteosarcoma. Multikinase inhibitors are a breakthrough in sarcoma management. Many trials are ongoing. Nevertheless, predictive factors are still missing.

The Landmark Series: Multimodality Treatment of Extremity Sarcoma

Multimodality treatment of primary soft tissue sarcoma has evolved over the last 50 years, including seminal studies in amputation versus limb-sparing surgery, incorporation of radiation therapy (XRT), and the continuing controversy over the utilization and efficacy of systemic chemotherapy. We review the landmark studies in the multimodality management of primary extremity and trunk soft tissue sarcoma.

Neoadjuvant Treatment Options in Soft Tissue Sarcomas

Due to the heterogeneity of soft tissue sarcomas (STS), the choice of the proper perioperative treatment regimen is challenging. Neoadjuvant therapy has attracted increasing attention due to several advantages, particularly in patients with locally advanced disease. The number of available neoadjuvant modalities is growing continuously. We may consider radiotherapy, chemotherapy, targeted therapy, radiosensitizers, hyperthermia, and their combinations. This review discusses possible neoadjuvant treatment options in STS with an emphasis on available evidence, indications for each treatment type, and related risks. Finally, we summarize current recommendations of the STS neoadjuvant therapy response assessment.

Response to Pazopanib in Patients With Relapsed Osteosarcoma

Axial skeleton primary tumor, metastatic disease at presentation, incomplete surgical resection, and <90% tumor necrosis have all been known to influence prognosis adversely in osteosarcoma. Relapse of osteosarcoma, typically occurring within the first 18 months of therapy, with an incidence rate of 50% is treated with surgery, chemotherapy, and targeted therapy. Here, we discuss 2 patients treated with pazopanib, a multi-tyrosine kinase inhibitor presently approved to treat renal cell carcinoma and soft tissue sarcomas. Case 1 achieved positive response and remains on pazopanib. Case 2 sustained gastrointestinal toxicity requiring suspension of drug, despite achieving stable disease.

Evolution in the management of soft tissue sarcoma: classification, surgery and use of radiotherapy

Background: Given the rapid evolution in the management of soft tissue sarcoma (STS), it is essential to revisit the evidence regularly. This review examines topics of interest for early management of STS: the impact of molecular genetics on sarcoma classification; the importance of a correct diagnosis and strategy in the surgical management of STS; current status on use of radiotherapy in STS.Areas covered: Accurate diagnosis of STS combines histomorphology, immunochemistry, and molecular genetics, although morphology is the mainstay of therapeutic planning. As diagnosis of STS is challenging, it is best conducted within a multidisciplinary environment. Expert surgery in STS takes into account multiple parameters including biopsy, imaging, pathological knowledge, technical issues, and a multidisciplinary approach. The sum of these factors informs decisions about whether or not to perform surgery and the choice of surgical technique. Advances in radiotherapy are challenging the paradigm of applying the same dose and treatment schedule to all STS patients irrespective of subtype. Preoperative radiotherapy of specific histotypes appears to be the future although more research is required to address uncertainties such as fraction size, total dose, combined modality regimens, and individual sensitivity to radiotherapy.Expert opinion: STS should be managed in a reference center.

Collective cancer invasion forms an integrin-dependent radioresistant niche

Cancer fatalities result from metastatic dissemination and therapy resistance, both processes that depend on signals from the tumor microenvironment. To identify how invasion and resistance programs cooperate, we used intravital microscopy of orthotopic sarcoma and melanoma xenografts. We demonstrate that these tumors invade collectively and that, specifically, cells within the invasion zone acquire increased resistance to radiotherapy, rapidly normalize DNA damage, and preferentially survive. Using a candidate-based approach to identify effectors of invasion-associated resistance, we targeted β1 and αVβ3/β5 integrins, essential extracellular matrix receptors in mesenchymal tumors, which mediate cancer progression and resistance. Combining radiotherapy with β1 or αV integrin monotargeting in invading tumors led to relapse and metastasis in 40-60% of the cohort, in line with recently failed clinical trials individually targeting integrins. However, when combined, anti-β1/αV integrin dual targeting achieved relapse-free radiosensitization and prevented metastatic escape. Collectively, invading cancer cells thus withstand radiotherapy and DNA damage by β1/αVβ3/β5 integrin cross-talk, but efficient radiosensitization can be achieved by multiple integrin targeting.

Trabectedin and RAdiotherapy in Soft Tissue Sarcoma (TRASTS): Results of a Phase I Study in Myxoid Liposarcoma from Spanish (GEIS), Italian (ISG), French (FSG) Sarcoma Groups

BACKGROUND

Myxoid liposarcoma (ML) exhibits a special sensitivity to trabectedin (T) and radiation therapy (RT). Preclinical data suggest a synergistic effect. We aimed to study safety, feasibility and activity of the administration of pre-operative concurrent T and RT in patients affected by localized resectable ML.

METHODS

Patients received 3 cycles (C) of T in combination with RT (45 Gy) in 25 fractions (1.8 Gy/fraction). Dose Levels for T were: - 1 (1.1 mg/m2), 0 (1.3 mg/m2) and 1 (1.5 mg/m2). Primary endpoint was safety; antitumor activity was assessed by RECIST and Choi criteria. This study is registered at ClinicalTrials.gov, number NCT02275286. The phase 1 part of the study is complete and phase 2 is ongoing.

FINDINGS

From February 2015 to May 2016, 14 patients (M/F 7/7), median age 36 years (range 24-70) and median tumor size 12.5 cm (range 7-17 cm), were enrolled. One dose limiting toxicity (G3 transaminitis) occurred at Level 0 and one (sepsis due to catheter infection) at Level 1. All patients completed RT. Five patients achieved PR (36%), 8 SD (57%), 1 distant PD (7%) by RECIST, while 12 achieved PR (86%), 1 SD (7%) and 1 distant PD (7%) by Choi criteria. Twelve patients underwent surgery. Median viable residual tumor was 5% (0-60).

INTERPRETATION

T in combination with RT showed a favorable safety profile and antitumor activity in localized ML. T dose of 1.5 mg/m2 is the recommended dose for the phase 2 study, which is ongoing.

FUNDING

This study was partially supported by Pharmamar.

Tumor necrosis and clinical outcomes following neoadjuvant therapy in soft tissue sarcoma: A systematic review and meta-analysis

BACKGROUND

The prognostic role of tumor necrosis following neoadjuvant therapy is established in bone sarcomas but remains unclear in soft tissue sarcomas (STS).

METHODS

We searched MEDLINE, MEDLINE in progress, EMBASE and Cochrane to identify studies that investigated neoadjuvant therapy in STS. Studies were required to report survival data based on extent of necrosis, or provided individual patient data allowing estimation thereof. Hazard ratios (HR) for relapse-free (RFS) and overall survival (OS) and odds ratios (OR) for recurrence at 3 years and for death at 5 years were pooled in a random effect meta-analysis. Associations between patient characteristics and attainment of ≥90% necrosis were explored.

RESULTS

21 studies comprising 1663 patients were included. Extremity tumors were most common (n = 1554; 93%). Induction regimens included chemotherapy with radiotherapy (n = 924; 56%), chemotherapy alone (n = 412; 25%), radiotherapy alone (n = 78; 5%), isolated limb perfusion (ILP) (n = 231; 14%), and targeted therapy/radiotherapy (n = 18; 1%). Patients with <90% necrosis had higher hazard of recurrence (hazard ratio [HR] 1.47; 95% CI: 1.06-2.04; p = 0.02) and death (HR 1.86; 95% CI: 1.41-2.46; p < 0.001). Risk of recurrence at 3 years (OR = 3.35; 95% CI: 2.27-4.92; p < 0.001) and of death at 5 years (OR 2.60; 95% CI: 1.59-4.26; p < 0.001) were similarly increased. Compared to other modalities, ILP was associated with higher odds of achieving ≥90% necrosis (OR 12.1; 95% CI: 3.69-39.88; p < 0.001).

CONCLUSION

Tumour necrosis <90% following neoadjuvant therapy is associated with increased recurrence risk and inferior OS in patients with STS.

The key role of pathology, surgery and radiotherapy in the initial management of soft tissue sarcoma

Soft tissue sarcomas are a heterogeneous group of rare malignancies. The diagnostic gold standard is conventional histomorphology with integrated immunohistochemistry. Molecular genetic profiling has identified new subgroups of undifferentiated sarcomas involving genetic rearrangements with creation of fusion genes. Accurate classification of sarcomas is critical for appropriate clinical decision-making which should involve a multidisciplinary team. A preoperative biopsy is necessary to confirm a diagnosis. Strategy is discussed in the multidisciplinary board. Reconstructive surgery must be planned in advance taking into account possible surgical morbidity. In high-risk situations, neo-adjuvant treatment could facilitate surgery in some cases, increase survival and provide indications of tumor biology. The decision is based on tumor subtype, grade and location, patient age and presence of comorbidities.

Radiotherapy and Vascular Endothelial Growth Factor Receptor-Tyrosine Kinase Inhibitors in Renal Cancer

Treatment of metastatic renal cell carcinoma (mRCC) has seen substantial progress over the last decade. A number of targeted therapies have been shown to improve clinical outcome. Vascular endothelial growth factor receptor (VEGFR)-tyrosine kinase inhibitors (TKIs) are an effective option in treating mRCC. RCC is traditionally perceived to be a radioresistant malignancy with a limited role of radiotherapy (RT) in the management of localized disease. While RCC appears to be radioresistant using conventionally fractionated RT, preclinical data suggest increased radiosensitivity when an ablative, hypofractionated schedule is used. RT is a common treatment for metastases; therefore, it is important to understand how best to use the combination of RT with targeted therapies. Preclinical studies have suggested that the combination of anti-angiogenic drugs with RT enhances the therapeutic effect compared with ionizing radiation alone. However, clinical data gave rise to warnings due to an increased incidence of severe gastrointestinal side effects. This article reviews the literature behind the preclinical and clinical data of the combination of RT with VEGFR-TKIs currently approved for RCC (sunitinib, sorafenib, pazopanib, and axitinib), with a focus on dose schedules as well as efficacy and toxicity.

Advances in sarcoma diagnostics and treatment

The heterogeneity of sarcomas with regard to molecular genesis, histology, clinical characteristics, and response to treatment makes management of these rare yet diverse neoplasms particularly challenging. This review encompasses recent developments in sarcoma diagnostics and treatment, including cytotoxic, targeted, epigenetic, and immune therapy agents. In the past year, groups internationally explored the impact of adding mandatory molecular testing to histological diagnosis, reporting some changes in diagnosis and/or management; however, the impact on outcomes could not be adequately assessed. Transcriptome sequencing techniques have brought forward new diagnostic tools for identifying fusions and/or characterizing unclassified entities. Next-generation sequencing and advanced molecular techniques were also applied to identify potential targets for directed and epigenetic therapy, where preclinical studies reported results for agents active within the receptor tyrosine kinase, mTOR, Notch, Wnt, Hedgehog, Hsp90, and MDM2 signaling networks. At the level of clinical practice, modest developments were seen for some sarcoma subtypes in conventional chemotherapy and in therapies targeting the pathways activated by various receptor tyrosine kinases. In the burgeoning field of immune therapy, sarcoma work is in its infancy; however, elaborate protocols for immune stimulation are being explored, and checkpoint blockade agents advance from preclinical models to clinical studies.

Perioperative Management of Extremity Soft Tissue Sarcomas

Surgery is potentially curative for primary nonmetastatic extremity soft tissue sarcomas. After surgery alone, patients may remain at risk for local recurrences and/or metastatic disease. To reduce the likelihood of a local relapse, the addition of radiotherapy (RT) to limb-sparing surgery may result in higher local control rates of at least 85%. Generally, it can be stated that local control after both preoperative and postoperative RT is comparable, but that preoperative RT comes with a more favorable toxicity profile after prolonged follow-up, albeit at the cost of a higher wound complication rate. Furthermore, recent data suggest that preoperative RT is more cost effective. To reduce the risk of subsequent metastatic disease, systemic chemotherapy can be introduced early during the primary management of these patients. These systemic chemotherapy regimens can also be applied both preoperatively and postoperatively. Finally, with the aim of increasing the antitumor response of perioperative RT, these agents may even be combined with RT, concurrently and sequentially. While designing new preoperative combination regimens, responses should be carefully monitored by both sophisticated radiologic and pathologic evaluations. This article reviews all these aspects, in addition to limb-sparing surgery.

A retrospective cohort study to assess adjuvant concurrent chemoradiation (CCRT) compared to adjuvant radiation therapy (RT) in the treatment of grade 2 and 3 extremity soft tissue sarcomas

PURPOSE

To evaluate the efficacy and tolerance of adjuvant concurrent chemoradiation (CCRT) as treatment of grade 2 and 3 (G2-3) localized extremity soft tissue sarcomas (STS) by comparing CCRT with standard adjuvant radiation therapy (RT).

PATIENTS AND METHODS

This monocentric retrospective study included non-pediatric patients (>16years) treated by adjuvant RT with or without chemotherapy (CT) after conservative resection of non-recurrent G2-3 extremity STS.

RESULTS

A total of 80 patients were treated between 1990 and 2012: 51 by RT and 29 by CCRT. Of the 29 CCRT patients, 25 received doxorubicin monotherapy (75mg/m²/3weeks). The CCRT group contained a greater proportion of grade 3 extremity STS (p<0.001). Median follow up was 68months (9-284). Multivariate analysis revealed greater local control in the CCRT group (1 local recurrence vs 8 in the RT group; HR=0.082, 95% CI 0.011-0.321) and incomplete resection as the major risk factor of local recurrence (HR=25.2, 95% CI 4.767-133.226). The two groups exhibited no differences in distant failure-free survival (HR=1.469, 95% CI 0.668-3.228), disease-free survival (HR=1.096, 95% CI 0.519-2.315) or overall survival (HR=1.378, 95% CI 0.498-3.814). Grade 3 was an adverse prognostic factor for overall survival (HR=3.11, 95% CI 1.04-9.32). Our analyses also revealed that CCRT tended to increase the risk of both grade ≥3 acute dermatitis (14 events vs 6 in the RT group; OR=6.99, 95% CI 2.28-21.47) and grade ≥2 late toxicity (6 events vs 3 in the RT group; p=0.0572).

CONCLUSION

CCRT could improve local control as part of a limb-preservation strategy. However, with a limited number of patients, CCRT showed no improvement in either distant control or survival and increased toxicity.

Combined high dose radiation and pazopanib in metastatic renal cell carcinoma: a phase I dose escalation trial

Background

The primary objective was to determine maximum tolerated radiation dose in patients with metastatic renal cell carcinoma on pazopanib treatment.

Methods

Treatment-naïve patients received pazopanib according to standard of care. Stereotactic body radiotherapy (SBRT) was delivered concurrently to the largest metastatic lesion at day 8, 10 and 12. SBRT doses were escalated in 3 dose levels (24 Gy/3, 30 Gy/3 and 36 Gy/3). Dose level was assigned using Time-to-Event Continual Reassessment Method with the target dose-limiting toxicity rate set to 0.25.

Results

Thirteen patients were included. One patient experienced dose limiting toxicity (DLT) at dose level 3 (grade 4 hypoglycemia). Maximum tolerated dose was not reached with a recommended dose of 36 Gy/3 having a probability of DLT of 11%. One-year local control was 83% (95% confidence interval 61–100) and 1-year progression-free survival was 28% (95% confidence interval 1–55).

Conclusions

SBRT in combination with pazopanib is well tolerated with good local control and response rates outside the radiation field.

Trial registration

This trial was retrospectively registered on clinicaltrials.gov(NCT02334709) on January 6th, 2015.

Electronic supplementary material

The online version of this article (10.1186/s13014-017-0893-x) contains supplementary material, which is available to authorized users.

The clinical application of angiostatic therapy in combination with radiotherapy: past, present, future

Although monotherapy with angiostatic drugs is still far from effective, there is abundant evidence that angiostatic therapy can improve the efficacy of conventional treatments like radiotherapy. This has instigated numerous efforts to optimize and clinically implement the combination of angiostatic drugs with radiation treatment. The results from past and present clinical trials that explored this combination therapy indeed show encouraging results. However, current findings also show that the combination has variable efficacy and is associated with increased toxicity. This indicates that combining radiotherapy with angiostatic drugs not only holds opportunities but also provides several challenges. In the current review, we provide an update of the most recent insights from clinical trials that evaluated the combination of angiostatic drugs with radiation treatment. In addition, we discuss the outstanding questions for future studies in order to improve the clinical benefit of combining angiostatic therapy with radiation therapy.

Looking for answers: the current status of neoadjuvant treatment in localized soft tissue sarcomas

PURPOSE

Sarcomas are a rare and heterogeneous variant of cancer. The standard of care treatment involves surgical resection with radiation in high-risk patients. Despite appropriate treatment approximately 50 % of patients will suffer and die from recurrent disease. The purpose of this article is to review the current evidence concerning the use of neoadjuvant chemotherapy with or without radiation in soft tissue sarcomas.

METHODS

An in-depth literature search was conducted using Ovid Medline and PubMed.

RESULTS

The most active chemotherapeutic agents in sarcoma are anthracyclines and ifosfamide. Adjuvant chemotherapy trials show only minimal benefit. Neoadjuvant chemotherapy offers the potential advantage of reducing the extent of surgery, increasing the limb salvage rate, early exposure of micrometastatic disease to chemotherapy, and assessment of tumor response to chemotherapy. Some retrospective and phase II trials suggest a benefit to neoadjuvant chemotherapy. Unfortunately, no clearly positive phase III prospectively randomized trials exist for neoadjuvant therapy in soft tissue sarcomas.

CONCLUSIONS

The current neoadjuvant chemotherapy trials that do exist are heterogeneous resulting in conflicting results. However, neoadjuvant chemotherapy with or without radiation can be considered in patients with high-risk disease in an attempt to improve long-term outcomes.

First-in-Human Study Testing a New Radioenhancer Using Nanoparticles (NBTXR3) Activated by Radiation Therapy in Patients with Locally Advanced Soft Tissue Sarcomas

Purpose: This phase I study aimed to determine the recommended dose (RD), safety profile, and feasibility of a procedure combining intratumoral injection of hafnium oxide nanoparticles (NBTXR3; a radioenhancer) and external beam radiotherapy (EBRT) for preoperative treatment of adults with locally advanced soft tissue sarcoma (STS).Experimental Design: Patients had a preoperative indication of EBRT for STS of the extremity or trunk. Baseline tumor volume (TV) was calculated by MRI. NBTXR3 was injected percutaneously into tumors at 53.3 g/L. Dose escalation was based on four levels equivalent to 2.5%, 5%, 10%, and 20% of baseline TV. NBTXR3 was visualized in the tumor 24 hours postinjection, and EBRT was initiated (50 Gy over 5 weeks). Surgery was performed 6 to 8 weeks after EBRT completion.Results: Twenty-two patients completed NBTXR3 injection, EBRT, and surgery and were followed for a median 22 months (range, 6-40). At NBTXR3 20% of TV, two dose-limiting toxicities occurred: injection-site pain and postoperative scar necrosis. The RD was defined as 10%. No leakage of NBTXR3 into surrounding tissues occurred; intratumor NBTXR3 levels were maintained during radiotherapy. At the RD, median tumor shrinkage was 40% (range 71% shrinkage, 22% increase); median percentage of residual viable tumor cells was 26% (range, 10%-90%). Patients receiving 20% of TV demonstrated pathologic complete responses. Seven grade 3 adverse events occurred, which were reversible.Conclusions: A single intratumoral injection of NBTXR3 at 10% of TV with preoperative EBRT was technically feasible with manageable toxicity; clinical activity was observed. Clin Cancer Res; 23(4); 908-17. ©2016 AACR.

Histology-Specific Uses of Tyrosine Kinase Inhibitors in Non-gastrointestinal Stromal Tumor Sarcomas

OPINION STATEMENT

Adult sarcomas, especially those with metastatic or unresectable disease, have limited treatment options. Traditional chemotherapeutic options have been limited by poor response rates in patients with advanced sarcomas. The important clinical question is whether the success of targeted therapy in GIST can be extended to other sarcomas and also if preclinical data describing targets across this heterogeneous group of cancers can be translated to clinical efficacy of known and upcoming target specific agents. Multi-targeted tyrosine kinase inhibitors (TKI) such as pazopanib, sorafenib, sunutinib, cediranib have shown benefits across various histologies of soft tissue sarcoma as well as bone sarcomas. The efficacy of imatinib in Dermatofibrosarcoma Protruberans; sunitinib and cediranib in alveolar soft part sarcoma; and sorafenib and imatinib in chordomas have provided a treatment option of these rare tumors where no effective options existed. TKIs are being tested in combination with chemotherapy as well as radiation to improve response. Although traditional RECIST criteria may not adequately reflect response to these targeted agents, the studies have shown promise for the efficacy of TKIs across the spectrum of sarcomas. The integration of biomarker studies with clinical trials may help further identify responders beyond that defined by histology. With the current data, TKIs are being used both as first-line treatment and beyond in non-GIST sarcomas.

[Radiotherapy for soft tissue sarcomas: Technical evolution and impact on clinical benefit]

The standard treatment for extremity soft tissue sarcomas is based on the association of surgery and radiotherapy. This strategy allows local control improvement with the risk of increased toxicity. There is therefore a growing interest to identify those patients who will benefit from radiotherapy and those who will have the same local control with surgery alone. Furthermore, the development of toxicity has been correlated with the extension of the irradiated volume and the volume receiving high doses. Technological development as intensity modulated radiotherapy and image-guided radiotherapy allows limited irradiated volume improving the protection of the organs at risk leading to clinical benefit improvement. Moreover, efforts are being done to improve local control for the patients at high risk of local relapse. In this paper, we discuss all these mentioned aspects.

Combined sunitinib and radiation therapy for preoperative treatment of soft tissue sarcoma: results of a phase I trial of the German interdisciplinary sarcoma group (GISG-03)

Background

Experimental data demonstrated that concurrent anti-angiogenic treatment with sunitinib may improve the efficacy of radiation therapy (RT). Here we report the results of a phase I trial performed within the German Interdisciplinary Sarcoma Group (GISG-03) of combined sunitinib and RT for neoadjuvant treatment of locally advanced soft tissue sarcoma (STS).

Methods

The primary endpoint of the study was to explore the recommended dose of sunitinib combined with RT for subsequent trials. Treatment response, postoperative complications after tumor resection and toxicity according to CTCAE 4.0 were secondary endpoints. The study used a 3 + 3 design. Patients received either 25 mg (dose level 1) or 37.5 mg (dose level 2) sunitinib two weeks prior to and throughout RT (28 × 1.8 Gy). Surgery was scheduled 5–8 weeks after completion of neoadjuvant treatment. Study registration: NCT01498835.

Results

Six patients were enrolled in dose level 1 and three patients in dose level 2. Median tumor size was 11 cm. Tumors were located in the retroperitoneum (4/9), lower leg (3/9) or trunk (2/9). At dose level 1, 1/6 patients developed dose limiting lymphopenia. At dose level 2, no patient developed dose limiting toxicity. Most frequent toxicities were hematological (8/9) and oral (5/9). Dose adjustments of sunitinib were necessary in 5/9 patients. All patients received full dose RT and underwent tumor resection (8/9 R0 and 1/9 R1). Local toxicity of RT did not exceed Grade 2. 2/9 patients had postoperative complications requiring re-intervention. Treatment response according to RECIST was as follows: partial response 1/9, stable disease 7/9, and progressive disease 1/9. Pathological examination revealed ≥ 95 % tumor necrosis in 3/9 resected specimens.

Conclusions

Combined sunitinib and RT was tolerable as neoadjuvant treatment for locally advanced STS patients regardless of tumor localization. The recommended sunitinib dose for subsequent trials is 37.5 mg.

Balancing efficacy of and host immune responses to cancer therapy: the yin and yang effects

Local and systemic treatments for cancer include surgery, radiation, chemotherapy, hormonal therapy, molecularly targeted therapies, antiangiogenic therapy, and immunotherapy. Many of these therapies can be curative in patients with early stage disease, but much less frequently is this the case when they are used to treat advanced-stage metastatic disease. In the latter setting, innate and/or acquired resistance are among the reasons for reduced responsiveness or nonresponsiveness to therapy, or for tumour relapse after an initial response. Most studies of resistance or reduced responsiveness focus on 'driver' genetic (or epigenetic) changes in the tumour-cell population. Several studies have highlighted the contribution of therapy-induced physiological changes in host tissues and cells that can reduce or even nullify the desired antitumour effects of therapy. These unwanted host effects can promote tumour-cell proliferation (repopulation) and even malignant aggressiveness. These effects occur as a result of systemic release of numerous cytokines, and mobilization of various host accessory cells, which can invade the treated tumour microenvironment. In short, the desired tumour-targeting effects of therapy (the 'yin') can be offset by a reactive host response (the 'yang'); proactively preventing or actively suppressing the latter represents a possible new approach to improving the efficacy of both local and systemic cancer therapies.

Integrative meta-analysis identifies microRNA-regulated networks in infantile hemangioma

BACKGROUND

Hemangioma is a common benign tumor in the childhood; however our knowledge about the molecular mechanisms of hemangioma development and progression are still limited. Currently, microRNAs (miRNAs) have been shown as gene expression regulators with an important role in disease pathogenesis. Our goals were to identify miRNA-mRNA expression networks associated with infantile hemangioma.

METHODS

We performed a meta-analysis of previously published gene expression datasets including 98 hemangioma samples. Deregulated genes were further used to identify microRNAs as potential regulators of gene expression in infantile hemangioma. Data were integrated using bioinformatics methods, and genes were mapped in proteins, which were then used to construct protein-protein interaction networks.

RESULTS

Deregulated genes play roles in cell growth and differentiation, cell signaling, angiogenesis and vasculogenesis. Regulatory networks identified included microRNAs miR-9, miR-939 and let-7 family; these microRNAs showed the most number of interactions with deregulated genes in infantile hemangioma, suggesting that they may have an important role in the molecular mechanisms of disease. Additionally, results were used to identify drug-gene interactions and druggable gene categories using Drug-Gene Interaction Database. We show that microRNAs and microRNA-target genes may be useful biomarkers for the development of novel therapeutic strategies for patients with infantile hemangioma.

CONCLUSIONS

microRNA-regulated pathways may play a role in infantile hemangioma development and progression and may be potentially useful for future development of novel therapeutic strategies for patients with infantile hemangioma.

Preoperative therapy with pazopanib in high-risk soft tissue sarcoma: a phase II window-of-opportunity study by the German Interdisciplinary Sarcoma Group (GISG-04/NOPASS)

INTRODUCTION

For resectable soft tissue sarcoma (STS), radical surgery, usually combined with radiotherapy, is the mainstay of treatment and the only potentially curative modality. Since surgery is often complicated by large tumour size and extensive tumour vasculature, preoperative treatment strategies with the aim of devitalising the tumour are being explored. One option is treatment with antiangiogenic drugs. The multikinase inhibitor pazopanib, which possesses pronounced antiangiogenic effects, has shown activity in metastatic and unresectable STS, but has so far not been tested in the preoperative setting.

METHODS AND ANALYSIS

This open-label, multicentre phase II window-of-opportunity trial assesses pazopanib as preoperative treatment of resectable STS. Participants receive a 21-day course of pazopanib 800 mg daily during wait time for surgery. Major eligibility criteria are resectable, high-risk adult STS of any location, or metachronous solitary STS metastasis for which resection is planned, and adequate organ function and performance status. The trial uses an exact single-stage design. The primary end point is metabolic response rate (MRR), that is, the proportion of patients with >50% reduction of the mean standardised uptake value (SUVmean) in post-treatment compared to pre-treatment fluorodeoxyglucose positron emission tomography CT. The MRR below which the treatment is considered ineffective is 0.2. The MRR above which the treatment warrants further exploration is 0.4. With a type I error of 5% and a power of 80%, the sample size is 35 evaluable patients, with 12 or more responders as threshold. Main secondary end points are histopathological and MRI response, resectability, toxicity, recurrence-free and overall survival. In a translational substudy, endothelial progenitor cells and vascular epithelial growth factor receptor are analysed as potential prognostic and predictive markers.

ETHICS AND DISSEMINATION

Approval by the ethics committee II, University of Heidelberg, Germany (2012-019F-MA), German Federal Institute for Drugs and Medical Devices (61-3910-4038155) and German Federal Institute for Radiation Protection (Z5-22463/2-2012-007).

TRIAL REGISTRATION NUMBER

NCT01543802, EudraCT: 2011-003745-18; Pre-results.

Preoperative radiotherapy for extremity soft tissue sarcoma; past, present and future perspectives on dose fractionation regimens and combined modality strategies

INTRODUCTION

This critical review aims to summarize published data on limb sparing surgery for extremity soft tissue sarcoma in combination with pre-operative radiotherapy (RT).

METHODS

This review is based on peer-reviewed publications using a PubMed search on the MeSH headings "soft tissue sarcoma" AND "preoperative radiotherapy". Titles and abstracts screened for data including "fraction size AND/OR total dose AND/OR overall treatment time", "chemotherapy", "targeted agents AND/OR tyrosine kinase inhibitors", are collated. Reference lists from some articles have been studied to obtain other pertinent articles. Additional abstracts presented at international sarcoma meetings have been included as well as information on relevant clinical trials available at the ClinicalTrials.gov website.

RESULTS

Data are presented for the conventional regimen of 50-50.4Gy in 25-28 fractions in 5-6 of weeks preoperative external beam RT with respect to the regimen's local control probability compared to surgery alone, as well as acute and late toxicities. The rationale and outcome data for hypofractionated and/or reduced dose regimens are discussed. Finally, combination schedules with conventional chemotherapy and/or targeted agents are summarized.

CONCLUSION

Outside the setting of well-designed prospective clinical trials, the conventional 50Gy in 5-6week schedule should be considered as standard. However, current and future studies addressing alternative fraction size, total dose, overall treatment time and/or combination with chemotherapy or targeted agents may reveal regimens of equal or increased efficacy with reduced late morbidities.

Combined radiation therapy and sunitinib for preoperative treatment of soft tissue sarcoma

BACKGROUND

Antiangiogenic substances and radiation therapy (RT) may have synergistic effects and improve irradiation efficacy. We present a cohort study evaluating the toxicity of combined sunitinib and RT as neoadjuvant treatment of extremity and retroperitoneal soft tissue sarcoma (STS).

METHODS

Sixteen patients with locally advanced extremity (6/16) or retroperitoneal (10/16) STS were treated with continuous-dosing sunitinib (15/16: 37.5 mg daily; 1/16: 25 mg daily) and standard RT (45-50.4 Gy) preoperatively. Surgery was scheduled 5-9 weeks following neoadjuvant treatment. The primary goal of the study was to determine combined treatment toxicity according to the Common Terminology Criteria for Adverse Events. Secondary goals were the evaluation of postoperative morbidity and treatment response.

RESULTS

Eight of 16 patients developed grade 3, and one patient developed grade 4, hematological toxicity. One patient experienced grade 3 hand-foot syndrome. The most frequent treatment toxicities of any grade were hematological (15/16) or dermatological (9/16). Three patients had partial response, 11 had stable disease, and 2 had progressive disease according to Response Evaluation Criteria in Solid Tumors (RECIST). Fourteen of 16 patients underwent surgery; tumors were not removed in two patients because of patient refusal or intercurrent metastatic disease. The proportion of tumor necrosis exceeded 90 % in 5 of 14 patients, and 4 patients had postoperative complications requiring reintervention.

CONCLUSIONS

Preoperative treatment with concurrent sunitinib and RT was tolerable, and postoperative morbidity did not increase. Combined treatment with RT and sunitinib was also feasible in patients with retroperitoneal STS, and warrants further investigation.