Time dependent dynamics of wound complications after preoperative radiotherapy in Extremity Soft Tissue Sarcomas

Unraveling the Myth of Radiation Resistance in Soft Tissue Sarcomas

There is a misconception that sarcomas are resistant to radiotherapy. This manuscript summarizes available (pre-) clinical data on the radiosensitivity of soft tissue sarcomas. Currently, clinical practice guidelines suggest irradiating sarcomas in 1.8-2 Gy once daily fractions. Careful observation of myxoid liposarcomas patients during preoperative radiotherapy led to the discovery of this subtype's remarkable radiosensitivity. It resulted subsequently in an international prospective clinical trial demonstrating the safety of a reduced total dose, yet still delivered with conventional 1.8-2 Gy fractions. In several areas of oncology, especially for tumors of epithelial origin where radiotherapy plays a curative role, the concurrent application of systemic compounds aiming for radiosensitization has been incorporated into routine clinical practice. This approach has also been investigated in sarcomas and is summarized in this manuscript. Observing relatively low α/β ratios after preclinical cellular investigations, investigators have explored hypofractionation with daily doses ranging from 2.85-8.0 Gy per day in prospective clinical studies, and the data are presented. Finally, we summarize work with mouse models and genomic investigations to predict observed responses to radiotherapy in sarcoma patients. Taken together, these data indicate that sarcomas are not resistant to radiation therapy.

Are We Ready for Life in the Fast Lane? A Critical Review of Preoperative Hypofractionated Radiotherapy for Localized Soft Tissue Sarcoma

This critical review aims to summarize the relevant published data regarding hypofractionation regimens for preoperative radiation therapy (RT) prior to surgery for soft tissue sarcoma (STS) of the extremity or superficial trunk. We identified peer-reviewed publications using a PubMed search on the MeSH headings of "soft tissue sarcoma" AND "hypofractionated radiation therapy." To obtain complication data on similar anatomical radiotherapeutic scenarios we also searched "hypofractionated radiation therapy" AND "melanoma" as well as "hypofractionated radiation therapy" AND "breast cancer." We then used reference lists from relevant articles to obtain additional pertinent publications. We also incorporated relevant abstracts presented at international sarcoma meetings and relevant clinical trials as listed on the ClinicalTrials.gov website. Detailed data are presented and contextualized for ultra-hypofractionated and moderately hypofractionated regimens with respect to local control, wound complications, and amputation rates. Comparative data are also presented for late toxicities including: fibrosis, joint limitation, edema, skin integrity, and bone fracture or necrosis. These data are compared to a standard regimen of 50 Gy in 25 daily fractions delivered over 5 weeks. This analysis supports the continued use of a standard regimen for preoperative RT for STS of 25 × 2 Gy over 5 weeks without concurrent chemotherapy. Use of concurrent chemotherapy with preoperative RT for STS should be reserved for well-designed clinical trials. A randomized trial of ultra-hypofractionated and moderately hypofractionated pre op RT for STS is warranted, but it is critical for the primary endpoint (or co-primary endpoint) to be late toxicity to: bone, soft tissue, joint, and skin.

A Systematic Review of the Orthoplastic Approach in Adult Lower Extremity Soft Tissue Sarcoma Flap Reconstruction

BACKGROUND

The orthoplastic approach to patient care has changed the way patients with a wide variety of lower extremity pathology are treated. Through a systematic review, we aim to analyze outcomes in adult patients with lower extremity soft tissue sarcomas who undergo an orthoplastic flap management approach to their care.

METHODS

A systematic review of adult lower extremity soft tissue sarcoma excision with plastic surgery flap reconstruction was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines searching the Pubmed, Embase, and Web of Science databases from inception to April 2023.

RESULTS

After removal of duplicates, title and abstract screening, and full-text review, 26 articles were accepted for inclusion. The total mean follow-up duration was 32.0 ± 24.3 months. Reconstruction used microvascular free flaps in 65.5% (487/743), while 34.5% (256/743) were local flaps. 85.8% (307/358) of patients ambulated postoperatively. Revision surgery was required in 21% of patients during their respective follow-up periods. The limb salvage rate was 93.4% (958/1,026). Among pooled surgical outcomes, 22.2% (225/1,012) of patients experienced a perioperative complication.

DISCUSSION

Our study demonstrates that although complication rates in lower extremity soft tissue sarcoma reconstruction may be further optimized, a multidisciplinary flap reconstructive approach provides high rates of limb salvage and functional postoperative ambulation.

Evaluation of the Prognostic Value of Pretherapeutic Magnetic Resonance Imaging in Predicting Soft Tissue Sarcoma Radiation Response: A Retrospective Study from a Large Institutional Sarcoma Imaging Database

Background: RT-induced hyalinization/fibrosis was recently evidenced as a significant independent predictor for complete response to neoadjuvant radiotherapy (RT) and survival in patients with soft tissue sarcoma (STS). Purpose: Non-invasive predictive markers of histologic response after neoadjuvant RT of STS are expected. Materials and Methods: From May 2010 to April 2017, patients with a diagnosis of STS who underwent neoadjuvant RT for limb STS were retrieved from a single center prospective clinical imaging database. Tumor Apparent Diffusion Coefficients (ADC) and areas under the time-intensity perfusion curve (AUC) were compared with the histologic necrosis ratio, fibrosis, and cellularity in post-surgical specimens. Results: We retrieved 29 patients. The median ADC value was 134.3 × 10-3 mm2/s. ADC values positively correlated with the post-treatment tumor necrosis ratio (p = 0.013). Median ADC values were lower in patients with less than 50% necrosis and higher in those with more than 50% (120.3 × 10-3 mm2/s and 202.0 × 10-3 mm2/s, respectively (p = 0.020). ADC values higher than 161 × 10-3 mm2/s presented a 95% sensitivity and a 55% specificity for the identification of tumors with more than 50% tumor necrosis ratio. Tumor-to-muscle AUC ratios were associated with histologic fibrosis (p = 0.036). Conclusions: ADC and perfusion AUC correlated, respectively, with radiation-induced tumor necrosis and fibrosis.

Incidence and risk of infection in malignant soft tissue tumor resection: Data from the nationwide soft tissue tumor registry

BACKGROUND

Postoperative infection is a devastating complication in limb salvage surgery for malignant soft tissue tumors. The low absolute case numbers of these rare cancers represent a bottleneck for data collection and analysis. The administration of nationwide registry data is a practical option for the accumulation of cases.

METHODS

Data on malignant soft tissue tumor resection were extracted from the Bone and Soft Tissue Tumor Registry in Japan. The incidence of postoperative infection and its risk factors were analyzed.

RESULTS

A total of 14,460 cases were included. The incidence of infection was 2.6%. Significant risks for infection were male sex, lower extremity or trunk location, tumor diameter of over 10 cm, trans-compartmental invasion, high grade, autologous bone graft, myocutaneous flap, vascular reconstruction, reconstruction by prosthesis, postoperative radiotherapy, and delayed wound healing.

CONCLUSIONS

The incidence was lower than those in the previous studies, perhaps because of less frequent radiotherapy application. Some of the significant risk factors represented local invasiveness of the tumor, suggesting the importance of the preservation of soft tissue for infection prevention. The administration of nationwide registry data was informative for the analysis of infection in malignant soft tissue tumor resection.

Postoperative drainage management and wound complications following resection of lower limb soft tissue tumors: a retrospective cohort study

PURPOSE

Postoperative wound complications are common in patients undergoing resection of lower extremity soft tissue tumors. Postoperative drainage therapy ensures adequate wound healing but may delay or complicate it. The aim of this study is to evaluate the incidence of postoperative wound complications and delayed or prolonged drainage treatment and to propose a standardized definition and severity grading of complex postoperative courses.

METHODS

A monocentric retrospective analysis of 80 patients who had undergone primary resection of lower extremity soft tissue tumors was performed. A new classification was developed, which takes into account postoperative drainage characteristics and wound complications. Based on this classification, risk factors and the prognostic value of daily drainage volumes were evaluated.

RESULTS

According to this new definition, regular postoperative course grade 0 (no wound complication and timely drainage removal) occurred in 26 patients (32.5%), grade A (minor wound complications or delayed drainage removal) in 12 (15.0%), grade B (major wound complication or prolonged drainage therapy) in 31 (38.8%), and grade C (reoperation) in 11 (13.7%) patients. Tumor-specific characteristics, such as tumor size (p = 0.0004), proximal tumor location (p = 0.0484), and tumor depth (p = 0.0138) were identified as risk factors for complex postoperative courses (grades B and C). Drainage volume on postoperative day 4 was a suitable predictor for complex courses (cutoff of 70 ml/d).

CONCLUSION

The proposed definition incorporates wound complications and drainage management while also being clinically relevant and easy to apply. It may serve as a standardized endpoint for assessing the postoperative course after resection of lower extremity soft tissue tumors.

Is the Addition of Anaerobic Coverage to Perioperative Antibiotic Prophylaxis During Soft Tissue Sarcoma Resection Associated With a Reduction in the Proportion of Wound Complications?

BACKGROUND

Wound complications are common after resection of soft tissue sarcomas, with published infection rates ranging from 10% to 35%. Multiple studies have reported on the atypical flora comprising these infections, which are often polymicrobial and contain anaerobic bacteria, and recent studies have noted the high prevalence of anaerobic bacterial infections after soft tissue sarcoma resection [ 26, 35 ]. Based on this, our institution changed clinical practice to include an antibiotic with anaerobic coverage in addition to the standard first-generation cephalosporin for prophylaxis during soft tissue sarcoma resections. The current study was undertaken to evaluate whether this change was associated with a change in major wound complications, and if the change should therefore be adopted for future patients.

QUESTIONS/PURPOSES

(1) After controlling for potentially confounding variables, was the broadening of the prophylactic antibiotic spectrum to cover anaerobic bacteria associated with a lower odds of major wound complications after soft tissue sarcoma resection? (2) Was the broadening of the prophylactic antibiotic spectrum to cover anaerobic bacteria associated with a lower odds of surgical site infections with polymicrobial or anaerobic infections after soft tissue sarcoma resection? (3) What are the factors associated with major wound complications after soft tissue sarcoma resection?

METHODS

We retrospectively identified 623 patients who underwent soft tissue sarcoma resection at a single center between January 2008 and January 2021 using procedural terminology codes. Of these, four (0.6%) pediatric patients were excluded, as were five (0.8%) patients with atypical lipomatous tumors and two (0.3%) patients with primary bone tumors; 5% (33 of 623) who were lost to follow-up, leaving 579 for final analysis. The prophylactic antibiotic regimen given at the resection and whether a wound complication occurred were recorded. Patients received the augmented regimen based on whether they underwent resection after the change in practice in July 2018. A total of 497 patients received a standard antibiotic regimen (usually a first-generation cephalosporin), and 82 patients received an augmented regimen with anaerobic coverage (most often metronidazole). Of the 579 patients, 53% (307) were male (53% [264 of 497] in the standard regimen and 52% [43 of 82] in the augmented regimen), and the mean age was 59 ± 17 years (59 ± 17 and 60 ±17 years in the standard and augmented groups, respectively). Wound complications were defined as any of the following within 120 days of the initial resection: formal wound debridement in the operating room, other interventions such as percutaneous drain placement, readmission for intravenous antibiotics, or deep wound packing for more than 120 days from the resection. Patients were considered to have a surgical site infection if positive cultures resulted from deep tissue cultures taken intraoperatively at the time of debridement. The proportion of patients with major wound complications was 26% (150 of 579); it was 27% (136 of 497) and 17% (14 of 82) in the standard and augmented antibiotic cohorts, respectively (p = 0.049). With the numbers we had, we could not document that the addition of antibiotics with anaerobic coverage was associated with lower odds of anaerobic (4% versus 6%; p = 0.51) or polymicrobial infections (9% versus 14%; p = 0.25). Patient, tumor, and treatment (surgical, radiotherapy, and chemotherapy) variables were collected to evaluate factors associated with overall infection and anaerobic or polymicrobial infection. Patient follow-up was 120 days to capture early wound complications. A multivariable analysis was performed for all variables found to be significant in the univariate analysis. A p value < 0.05 was used as the threshold for statistical significance for all analyses. No patients were found to have an adverse reaction to the augmented regimen, including allergic reactions or Clostridioides (formerly Clostridium) difficile infection.

RESULTS

After controlling for other potentially confounding factors such as neoadjuvant radiation, tumor size and anatomic location, as well as patient BMI, anaerobic coverage was associated with smaller odds of wound complications (OR 0.36 [95% confidence interval (CI) 0.18 to 0.68]; p = 0.003). Other factors associated with major wound complications were preoperative radiation (versus no preoperative radiation) (OR 2.66 [95% CI 1.72 to 4.15]; p < 0.001), increasing tumor size (OR 1.04 [95% CI 1.00 to 1.07]; p = 0.03), patient BMI (OR 1.07 [95% CI 1.04 to 1.11]; p < 0.001), and tumor in the distal upper extremity (versus proximal upper extremity, pelvis/groin/hip, and lower extremity) (OR 0.18 [95% CI 0.04 to 0.62]; p = 0.01).

CONCLUSION

The addition of anaerobic coverage to the standard prophylactic regimen during soft tissue sarcoma resection demonstrated an association with smaller odds of major wound complications and no documented adverse reactions. Treating physicians should consider these findings but note that they are preliminary, and that further work is needed to replicate them in a more controlled study design such as a prospective trial.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Clinical reliability of pedicled perforator flaps in the management of adult limb and trunk soft tissue sarcomas: Experience of two French expert centres

INTRODUCTION

Limb-sparing surgery combined with radiation has become the standard treatment for soft tissue sarcomas. Despite the many advantages of reconstruction procedures, such as muscle-sparing flap and local reconstruction, the use of pedicled perforator flaps remains non-consensual due to doubts about their reliability when associated with radiotherapy. This study evaluated their surgical reliability in reconstructive surgery for limb and trunk soft tissue sarcomas, in terms of healing time, wound disorders, and postoperative complications, regardless of radiation timing.

PATIENTS AND METHODS

We realized a retrospective, observational, bi-center study (Cancer University Institute of Toulouse Oncopole, France and Bergonié Institute Bordeaux, France) and describes pedicled perforator flaps performed between January 2015 and January 2021.

RESULTS

A total of 74 flaps were included. The median age of the population was 70-year-old. The group consisted of 68.8% (n = 51/74) propeller flaps. We found a partial necrosis rate of 28.4% (n = 21/74), scar disunion of 48.6% (n = 36/74), local infection of 10.8% (n = 8/74), and venous congestion of 13.5% (n = 10/74). Only 16.2% (n = 12/74) required secondary surgical repair to a local complication. The average length of stay was 7.3 days  [1.0-25.0]. The mean operating time of our flaps was 133.4 min [38.0-280.0].

CONCLUSIONS

Pedicled perforator flaps are a surgical technique that can be used in reconstructive surgery for limb and trunk soft tissue sarcomas in adults, regardless of radiation timing. However, these flaps carry a high rate of postoperative complications so they should be reserved for expert surgeons in referral centers.

Preoperative hypofractionated radiotherapy for soft tissue sarcomas: a systematic review

Background

Soft tissue sarcomas (STS) represent a diverse group of rare malignant tumors. Currently, five to six weeks of preoperative radiotherapy (RT) combined with surgery constitute the mainstay of therapy for localized high-grade sarcomas (G2–G3). Growing evidence suggests that shortening preoperative RT courses by hypofractionation neither increases toxicity rates nor impairs oncological outcomes. Instead, shortening RT courses may improve therapy adherence, raise cost-effectiveness, and provide more treatment opportunities for a wider range of patients. Presumed higher rates of adverse effects and worse outcomes are concerns about hypofractionated RT (HFRT) for STS. This systematic review summarizes the current evidence on preoperative HFRT for the treatment of STS and discusses toxicity and oncological outcomes compared to normofractionated RT.

Methods

We conducted a systematic review of clinical trials describing outcomes for preoperative HFRT in the management of STS using PubMed, the Cochrane library, the Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, Embase, and Ovid Medline. We followed the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Trials on retroperitoneal sarcomas, postoperative RT, and hyperthermia were excluded. Articles published until November 30th, 2021, were included.

Results

Initial search yielded 94 articles. After removal of duplicate and ineligible articles, 13 articles qualified for analysis. Eight phase II trials and five retrospective analyses were reviewed. Most trials applied 5 × 5 Gy preoperatively in patients with high-grade STS. HFRT courses did not show increased rates of adverse events compared to historical trials of normofractionated RT. Toxicity rates were mostly comparable or lower than in trials of normofractionated RT. Moreover, HFRT achieved comparable local control rates with shorter duration of therapy. Currently, more than 15 prospective studies on HFRT + / − chemotherapy are ongoing.

Conclusions

Retrospective data and phase II trials suggest preoperative HFRT to be a reasonable treatment modality for STS. Oncological outcomes and toxicity profiles were favorable. To date, our knowledge is mostly derived from phase II data. No randomized phase III trial comparing normofractionated and HFRT in STS has been published yet. Multiple ongoing phase II trials applying HFRT to investigate acute and late toxicity will hopefully bring forth valuable findings.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13014-022-02072-9.

Preoperative ultra-hypofractionation radiotherapy in extremity/trunk wall soft tissue sarcoma - A meta-analysis of prospective studies

PURPOSE

The neoadjuvant radiotherapy is now standard treatment in soft tissue sarcoma. Using ultra-hypofractionation radiotherapy shorten the treatment time. In the era of COVID pandemic, using less fraction to treat patient is an urgent need. Thus, we aim to use meta-analysis to investigate the clinical efficacy of preoperative stereotactic body radiotherapy.

MATERIAL AND METHODS

PRISMA guideline was used in this study. PubMed, Cochrane and Embase were used. We include only prospective study. The main endpoint was set as wound complication rate. Other endpoints include R0 resection rate, overall survival, local control, and distant metastasis free survival.

RESULTS

Seven studies were included. The pooled wound complication rate is 0.30 (95% CI=0.26-0.35). The pooled R0 resection rate is 0.87(95%CI: 0.74-0.94). The pooled 2-year overall survival is 0.86 (95%CI: 0.72-0.94). The pooled 2-year local control rate is 0.96(95%CI: 0.89-0.99). The pooled 2-year distant metastasis free survival is 0.60 (95%CI=0.50-0.70).

CONCLUSION

Neoadjuvant ultra-hypofractionation radiotherapy in soft tissue sarcoma is a feasible and well tolerable treatment.

Soft Tissue Sarcomas: Is Pre-operative Radiotherapy Associated With More Acute Wound Complications?

Introduction: Increased wound complication rates are attributed to the use of pre-operative radiotherapy. The purpose of this study is to evaluate the incidence of complications with or without pre-operative radiotherapy in our institution.

Methods: We retrospectively evaluated 48 adult patients with high-grade extremity soft tissue sarcoma. Twenty-two patients received pre-operative radiotherapy (group A) while 26 patients underwent initial surgery (group B). Complications were defined as major wound complications if they were severe enough to delay the delivery of adjuvant treatment (chemotherapy or radiotherapy) more than eight weeks after surgery or if their resolution required a new surgical intervention.

Results: Mean follow-up in group A and group B was 44.3 and 53.8 months, respectively. The incidence of complications of any grade in group A was 45.5% and 53.8% in group B (p: 0.566). Major wound complications in group A and group B occurred in 18% and 23% of the patients (p=0.630), respectively. All patients in group A completed local treatment - radiotherapy and surgery - in 66 days on average. In contrast, in group B post-operative radiotherapy was either delayed or suspended in four patients due to wound complications. This determined that 15.4% of the patients in group B did not receive the local treatment - surgery + radiotherapy - as planned.

Conclusions: An increased risk of severe acute wound complications with the administration of pre-operative radiotherapy was not observed in patients with soft tissue sarcomas of the extremities. In addition, local treatment completion was not jeopardized with preoperative radiotherapy, as opposed to post-operative radiotherapy.

Cellular Radiosensitivity of Soft Tissue Sarcoma

Currently, all soft tissue sarcomas (STS) are irradiated by the same regimen, disregarding possible subtype-specific radiosensitivities. To gain further insight, cellular radiosensitivity was investigated in a panel of sarcoma cell lines. Fourteen sarcoma cell lines, derived from synovial sarcoma, leiomyosarcoma, fibrosarcoma and liposarcoma origin, were submitted to clonogenic survival assays. Cells were irradiated with single doses from 1-8 Gy and surviving fraction (SF) was calculated from the resulting response data. Alpha/beta (α/β) ratios were inferred from radiation-response curves using the linear-quadratic (LQ)-model. Cellular radiosensitivities varied largely in this panel, indicating a considerable degree of heterogeneity. Surviving fraction after 2 Gy (SF2) ranged from 0.27 to 0.76 with evidence of a particular radiosensitive phenotype in only few cell lines. D37% on the mean data was 3.4 Gy and the median SF2 was 0.52. The median α/β was 4.9 Gy and in six cell lines the α/β was below 4 Gy. A fairly homogeneous radiation response was observed in myxoid liposarcoma cell lines with SF2 between 0.64 and 0.67. Further comparing sarcomas of different origin, synovial sarcomas, as a group, showed the lowest SF2 values (mean 0.35) and was significantly more radiosensitive than myxoid liposarcomas and leiomyosarcomas (P = 0.0084 and 0.024, respectively). This study demonstrates a broad spectrum of radiosensitivities across STS cell lines and reveals subtype-specific radiation responses. The particular cellular radiosensitivity of synovial sarcoma cells supports consideration of the different sarcoma entities in clinical studies that aim to optimize sarcoma radiotherapy.

The Interval Between Preoperative Radiation and Surgery Is Not Associated with Overall Survival for Soft-tissue Sarcomas: An Analysis of the National Cancer Database

BACKGROUND

Most cancer centers prefer preoperative radiation therapy (preRT) over postoperative therapy to treat soft-tissue sarcoma (STS) to limit long-term fibrosis, joint stiffness, and edema. Surgery is often delayed after preRT to allow for tissue recovery and to reduce wound complications. However, the association between the time interval between preRT and surgery and survival is unknown.

QUESTIONS/PURPOSES

(1) What factors are associated with the preRT-surgery interval in patients with STS? (2) Is the preRT-surgery interval associated with overall survival?

METHODS

The National Cancer Database, a nationwide registry that includes 70% of all new cancers in the United States with 90% follow-up, was reviewed to identify 6378 patients who underwent preRT and surgical resection for a localized extremity or pelvic STS from 2004 to 2014. Patients were excluded if they had lymphatic or metastatic disease at diagnosis (23%; n = 1438), underwent neoadjuvant chemotherapy (24%; 1531), were missing vital status (8%; 487), had chemosensitive histologies (9%; 603), underwent radiation other than external beam (1%; 92), were missing preRT-surgery interval (1%; 45), or had a preRT-surgery interval greater than 120 days (< 1%; 6). A total of 2176 patients were included for analysis, with a mean preRT-surgery interval of 35 ± 16 days. A multiple linear regression model was generated to assess demographic, clinicopathologic, and treatment characteristics associated with the preRT-surgery interval. A Kaplan-Meier survival analysis was then conducted, stratified by the preRT-surgery interval, to assess survival over 10 years. Finally, a multivariate Cox regression analysis model was constructed to further evaluate the association between the preRT-surgery interval and overall survival, adjusted for demographic, clinicopathologic, and treatment characteristics.

RESULTS

A longer preRT-surgery interval was associated with higher age (β = 0.002 per year [95% CI 0.0 to 0.004]; p = 0.026), tumor location in the pelvis (compared with the lower extremity; β = 0.15 [95% CI 0.082 to 0.22]; p < 0.001), and malignant peripheral nerve sheath tumor subtype (compared with undifferentiated pleomorphic sarcoma; β = 0.17 [95% CI 0.044 to 0.29]; p = 0.008). A shorter preRT-surgery interval was associated with higher facility volume (β = -0.002 per case [95% CI -0.003 to -0.002]; p = 0.026) and higher tumor stage (compared with Stage I; β = -0.066 [95% CI -0.13 to -0.006]; p = 0.03 for Stage II; β = -0.12 [95% CI -0.17 to -0.065]; p < 0.001 for Stage III). The 5-year overall survival rates were similar across all preRT-surgery interval groups: less than 3 weeks (66% [95% CI 60 to 72]), 3 to 4 weeks (65% [95% CI 60 to 71]), 4 to 5 weeks (65% [95% CI 60 to 71]), 5 to 6 weeks (66% [95% CI 60 to 72]), 6 to 7 weeks (63% [95% CI 54 to 72]), 7 to 9 weeks (66% [95% CI 58 to 74]), and more than 9 weeks (59% [95% CI 48 to 69]). Over 10 years, no difference in overall survival was observed when stratified by the preRT-surgery interval (p = 0.74). After controlling for potentially confounding variables, including age, sex, Charlson/Deyo comorbidity score, histology, tumor size, stage and surgery type, the preRT-surgery interval was not associated with survival (hazard ratio = 1 per day [95% CI 1 to 1]; p = 0.88).

CONCLUSION

With the numbers available, this study demonstrates that a delay in surgery up to 120 days after radiation is not associated with poorer survival. Therefore, clinicians may be able to delay surgery to minimize the risks of wound complications and modifiable comorbidities without affecting overall survival.Level of Evidence Level III, therapeutic study.

Local Control For High-Grade Nonrhabdomyosarcoma Soft Tissue Sarcoma Assigned to Radiation Therapy on ARST0332: A Report From the Childrens Oncology Group

PURPOSE

The ARST0332 trial for pediatric and young adults with nonrhabdomyosarcoma soft tissue sarcoma (NRSTS) used risk-based treatment including primary resection with lower-than-standard radiation doses to optimize local control (LC) while minimizing long-term toxicity in those requiring radiation therapy (RT). RT for high-grade NRSTS was based on extent of resection (R0: negative margins, R1: microscopic margins, R2/U: gross disease/unresectable); those with >5 cm tumors received chemotherapy (CT; ifosfamide/doxorubicin). This analysis evaluates LC for patients assigned to RT and prognostic factors associated with local recurrence (LR).

METHODS AND MATERIALS

Patients aged <30 years with high-grade NRSTS received RT (55.8 Gy) for R1 ≤5 cm tumor (arm B); RT (55.8 Gy)/CT for R0/R1 >5 cm tumor (arm C); or neoadjuvant RT (45 Gy)/CT plus delayed surgery, CT, and postoperative boost to 10.8 Gy R0 <5 mm margins/R1 or 19.8 Gy for R2/unresected tumors (arm D).

RESULTS

One hundred ninety-three eligible patients had 24 LRs (arm B 1/15 [6.7%], arm C 7/65 [10.8%], arm D 16/113 [14.2%]) at median time to LR of 1.1 years (range, 0.11-5.27). Of 95 eligible for delayed surgery after neoadjuvant therapy, 89 (93.7%) achieved R0/R1 margins. Overall LC after RT were as follows: R0, 106 of 109 (97%); R1, 51 of 60 (85%); and R2/unresectable, 2 of 6 (33%). LR predictors include extent of delayed resection (P <.001), imaging response before delayed surgery (P < .001), histologic subtype (P <.001), and no RT (P = .046). The 5-year event-free survival was significantly lower (P = .0003) for patients unable to undergo R0/R1 resection.

CONCLUSIONS

Risk-based treatment for young patients with high-grade NRSTS treated on ARST0332 produced very high LC, particularly after R0 resection (97%), despite lower-than-standard RT doses. Neoadjuvant CT/RT enabled delayed R0/R1 resection in most patients and is preferred over adjuvant therapy due to the lower RT dose delivered.

Dose Reduction of Preoperative Radiotherapy in Myxoid Liposarcoma: A Nonrandomized Controlled Trial

IMPORTANCE

Currently, preoperative radiotherapy for all soft-tissue sarcomas is identical at a 50-Gy dose level, which can be associated with morbidity, particularly wound complications. The observed clinical radiosensitivity of the myxoid liposarcoma subtype might offer the possibility to reduce morbidity.

OBJECTIVE

To assess whether a dose reduction of preoperative radiotherapy for myxoid liposarcoma would result in comparable oncological outcome with less morbidity.

DESIGN, SETTING, AND PARTICIPANTS

The Dose Reduction of Preoperative Radiotherapy in Myxoid Liposarcomas (DOREMY) trial is a prospective, single-group, phase 2 nonrandomized controlled trial being conducted in 9 tertiary sarcoma centers in Europe and the US. Participants include adults with nonmetastatic, biopsy-proven and translocation-confirmed myxoid liposarcoma of the extremity or trunk who were enrolled between November 24, 2010, and August 1, 2019. Data analyses, using both per-protocol and intention-to-treat approaches, were conducted from November 24, 2010, to January 31, 2020.

INTERVENTIONS

The experimental preoperative radiotherapy regimen consisted of 36 Gy in once-daily 2-Gy fractions, with subsequent definitive surgical resection after an interval of 4 or more weeks.

MAIN OUTCOMES AND MEASURES

As a short-term evaluable surrogate for local control, the primary end point was centrally reviewed pathologic treatment response. The experimental regimen was regarded as a success when 70% or more of the resection specimens showed extensive treatment response, defined as 50% or greater of the tumor volume containing treatment effects. Morbidity outcomes consisted of wound complications and late toxic effects.

RESULTS

Among the 79 eligible patients, 44 (56%) were men and the median (interquartile range) age was 45 (39-56) years. Two patients did not undergo surgical resection because of intercurrent metastatic disease. Extensive pathological treatment response was observed in 70 of 77 patients (91%; posterior mean, 90.4%; 95% highest probability density interval, 83.8%-96.4%). The local control rate was 100%. The rate of wound complication requiring intervention was 17%, and the rate of grade 2 or higher toxic effects was 14%.

CONCLUSIONS AND RELEVANCE

The findings of the DOREMY nonrandomized clinical trial suggest that deintensification of preoperative radiotherapy dose is effective and oncologically safe and is associated with less morbidity than historical controls, although differences in radiotherapy techniques and follow-up should be considered. A 36-Gy dose delivered in once-daily 2-Gy fractions is proposed as a dose-fractionation approach for myxoid liposarcoma, given that phase 3 trials are logistically impossible to execute in rare cancers.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02106312.

Factors associated with 30-day soft tissue complications following upper extremity sarcoma surgery

BACKGROUND AND OBJECTIVES

The incidence of soft tissue complications following sarcoma surgery in the upper extremity is reportedly high. Therefore, this study assessed the National Surgical Quality Improvement Program (NSQIP) database to identify independent risk factors, while also reporting the incidence of soft tissue complications in the first 30 days after surgery.

METHODS

A total of 620 patients that underwent surgical treatment for upper extremity sarcoma were included from the NSQIP database. Soft tissue complications were defined as surgical site infection, wound dehiscence, or soft-tissue related reoperations. Clinically relevant patient and treatment characteristics were selected and analyzed.

RESULTS

The 30-day soft tissue complication rate was 4.7%. In the multivariable analysis, higher body mass index (p = .047) and longer operative times (p = .002) were independently associated with soft tissue complications.

CONCLUSIONS

Higher body mass index and longer operative times are risk factors for soft tissue complications following upper extremity sarcoma surgery. The soft-tissue complication rate following resection of upper extremity tumors is low in this national cohort, possibly due to the relatively small tumor size and low prevalence of radiotherapy.

Preoperative accelerated radiotherapy combined with chemotherapy in a defined cohort of patients with high risk soft tissue sarcoma: a Scandinavian Sarcoma Group study

Background

We recently reported outcomes from a Scandinavian Sarcoma Group adjuvant study (SSG XX group A) conducted on localized and operable high risk soft tissue sarcoma (STS) of the extremities and trunk wall. SSG XX, group B, comprised of patients in a defined cohort with locally advanced STS considered at high risk for intralesional surgery. These patients received preoperative accelerated radiotherapy, together with neoadjuvant and adjuvant chemotherapy. Herein we report the results of this group B.

Methods

Twenty patients with high-grade, locally advanced and deep STS located in lower extremities (n = 12), upper extremities (5) or trunk wall (3) were included. The median age was 59 years and 14 patients were males. The treatment regimen consisted of 6 cycles of doxorubicin (60 mg/m²) and ifosfamide (6 g/m²), with three cycles given neoadjuvantly, and preoperative radiotherapy (1, 8 Gyx2/daily to 36 Gy) between cycles 2 and 3. After a repeated MRI surgery was then conducted, and the remaining 3 chemotherapy cycles were given postoperatively at 3 weeks intervals. Survival data, local control, toxicity of chemotherapy and postoperative complications are presented.

Results

Median follow-up time for metastasis-free survival (MFS) was 2.8 years (range 0.3–10.4). The 5-year MFS was 49.5% (95% confidence interval [CI] 31.7–77.4). The median follow-up time was 5.4 years (range 0.3–10.4) for overall survival (OS). The 5-year OS was 64.0% (95% CI 45.8–89.4). The median tumour size was 13 cm, with undifferentiated pleomorphic sarcoma (n = 10) and synovial sarcoma (n = 6) diagnosed most frequently. All patients completed surgery. Resection margins were R0 in 19 patients and R1 in 1 patient. No patients had evidence of disease progression preoperatively. Three patients experienced a local recurrence, in 2 after lung metastases had already been diagnosed. Eleven patients (55%) had postoperative wound problems (temporary in 8 and persistent in 3).

Conclusions

Preoperative chemotherapy and radiotherapy were associated with temporary wound-healing problems. Survival outcomes, local control and toxicities were deemed satisfactory when considering the locally advanced sarcoma disease status at primary diagnosis.

Trial registration This study was registered at ClinicalTrials.gov Identifier NCT00790244 and with European Union Drug Regulating Authorities Clinical Trials No. EUDRACT 2007-001152-39

Six-Week Interval Between Preoperative Radiation and Surgery Is Associated With Fewer Major Wound Complications in Soft Tissue Sarcoma

OBJECTIVES

A total of 30% to 40% of soft tissue sarcoma (STS) patients develop major wound complications (MWCs) after preoperative radiation (preRT). The optimal preRT-surgery interval and its association with MWCs is unknown. This study investigated whether a longer preRT-surgery interval is associated with fewer MWCs compared with historical controls.

METHODS

All patients treated by a single surgeon after preRT with limb-sparing wide resection for extremity and trunk STS were retrospectively reviewed from 2004 to 2014. The primary outcome was MWCs defined as a secondary operation, invasive procedure, wound packing, or readmission for wound care. Secondary outcomes of local recurrence and survival were followed and independent variables were analyzed for an association with MWCs.

RESULTS

Fifty-four patients were included with a median follow-up of 32 months and age of 61 years. The majority of tumors were deep (91%), large (median size of 11 cm), high grade (78%) and within the lower extremity (78%). The median preRT-surgery interval was 43 days and 80% of patients received surgery 35 to 49 days after radiation. MWCs were observed in 15% of patients and 88% occurred within 40 days. Predictors for MWCs on multivariate analysis were peripheral vascular disease (P=0.03), location in the medial compartment of the thigh (P=0.03), and neurovascular involvement (P=0.03).

CONCLUSIONS

This study presents a cohort of STS patients with an extended preRT-surgery interval of ~6 weeks. MWCs in this population occurred at a lower rate than historical controls. Overall these findings support the exploration of a longer interval to reduce MWCs and their associated morbidity.

A Phase II Trial of 5-Day Neoadjuvant Radiotherapy for Patients with High-Risk Primary Soft Tissue Sarcoma

PURPOSE

In a single-institution phase II study, we evaluated the safety of a 5-day dose-equivalent neoadjuvant radiotherapy (RT) regimen for high-risk primary soft tissue sarcoma.

PATIENTS AND METHODS

Patients received neoadjuvant RT alone (30 Gy in five fractions) to the primary tumor with standard margins. The primary endpoint was grade ≥2 late-radiation toxicity. Major wound complications, local recurrences, and distant metastases were also examined. In exploratory analysis, we evaluated germline biomarkers for wound toxicity and the effects of the study on treatment utilization.

RESULTS

Over 2 years, 52 patients were enrolled with median follow-up of 29 months. Seven of 44 evaluable patients (16%) developed grade ≥2 late toxicity. Major wound complications occurred in 16 of 50 patients (32%); a signature defined by 19 germline SNPs in miRNA-binding sites of immune and DNA damage response genes, in addition to lower extremity tumor location, demonstrated strong predictive performance for major wound complications. Compared with the preceding 2-year period, the number of patients treated with neoadjuvant RT alone at our institution increased 3-fold, with a concomitant increase in the catchment area.

CONCLUSIONS

A shorter 5-day neoadjuvant RT regimen results in favorable rates of wound complications and grade ≥2 toxicity after 2-year follow-up. Five-day RT significantly increased utilization of neoadjuvant RT at our high-volume sarcoma center. With further validation, a putative germline biomarker for wound complications may guide safer RT utilization.

[Principles of sarcoma surgery]

Soft-tissue sarcomas are rare malignant tumors. Surgery remains the most important treatment modality. Neoadjuvant and/or adjuvant chemo- and radiotherapy may be administered to improve the local and systemic outcome. Advances in oncological and reconstructive surgery, combined with the use of multimodal therapies, have made mutilating surgery rare events in extremity sarcomas. In retroperitoneal sarcomas, local recurrences are life-threatening events and multivisceral resection has become the standard surgical procedure. The subjects of this review are diagnostics, multimodal therapy, and resection strategy from a surgical point of view.

[Systematic planning of surgery for soft tissue sarcoma of the extremities]

Soft tissue sarcomas of the extremities are rarely malignant tumors. They are best treated by an experienced interdisciplinary sarcoma team. A preoperative biopsy and imaging are prerequisites for successful sarcoma treatment. Before surgery the multimodal treatment and the extent of resection and, if necessary, plastic reconstruction should be discussed in a multidisciplinary tumor board. The aim is always a complete R0 resection with optimal preservation of function. The preservation of critical structures (e. g. sciatic nerve) by a planned focal marginal resection along the critical structure can be performed by an experienced team in a multidisciplinary treatment setting.