Prognostic factors of extremity soft tissue sarcoma in adults. A single institutional analysis

Brachytherapy in the Treatment of Soft-Tissue Sarcomas of the Extremities-A Current Concept and Systematic Review of the Literature

INTRODUCTION

Evidence on the use of brachytherapy in soft-tissue sarcoma (STS) is sparse. Therapy regimens are determined more by local interdisciplinary tumor conferences than by standardized protocols. Patient-specific factors complicate the standardized application of therapy protocols. The individuality of the treatment makes it difficult to compare results.

MATERIALS AND METHODS

A comprehensive literature search was conducted, whereby the literature from a period of almost 44 years (1977-2021) was graded and included in this systematic review. For this purpose, PubMed was used as the primary database. Search string included "soft-tissue sarcoma", "brachytherapy", and "extremity." Four independent researchers reviewed the literature. Only full-text articles written in English or German were included.

RESULTS

Of the 175 identified studies, 70 were eligible for analysis based on the inclusion and exclusion criteria. The key points to compare were local complications, recurrence rate and correlation with margins of resection, and the use of brachytherapy regarding tumor grading.

CONCLUSION

Brachytherapy represents an important subset of radiotherapy techniques used in STSs, whose indications and applications are constantly evolving, and for which a local control rate of 50% to 96% has been reported as monotherapy, depending on risk factors. However, the best benefit is seen in the combination of further resection and brachytherapy, and most authors at many other centers agree with this treatment strategy.

Neoadjuvant Radiotherapy is Associated with R0 Resection and Improved Survival for Patients with Extremity Soft Tissue Sarcoma Undergoing Surgery: A National Cancer Database Analysis

BACKGROUND

Neoadjuvant radiotherapy (RT) is increasingly advocated for the management of soft tissue sarcoma (STS). Therefore, this study sought to characterize the impact of neoadjuvant RT on rates of R0 resection and overall survival (OS) in extremity STS patients undergoing surgery.

METHODS

From January 2003 to December 2012, the study identified patients with a diagnosis of extremity STS from the National Cancer Database. After exclusion of patients younger than 18 years, not treated by surgery, who had metastases at diagnosis, intraoperative RT, and missing or unknown data, 27,969 patients were identified. Logistic regression and Cox-proportional hazard analysis were used to compare rates of R0 resection among preoperative, postoperative, and no-RT cohorts and to determine predictors of R0 resection and OS.

RESULTS

The mean age of the patients was 59.5 ± 17.1 years, and 45.9% were female. The median tumor size was 10.5 cm. The data showed that 51% of the patients did not receive RT, 11.8% received preoperative RT, and 37.2% received postoperative RT. The rates of R0 resection were 90.1% for the preoperative RT cohort, 74.9% for the postoperative RT cohort, and 79.9% for the no-RT cohort (P < 0.001). The independent predictors for achievement of R0 resection included academic facility type (odds ratio [OR] 1.36; 95% confidence interval [CI] 1.20-1.55), histologic subtype, tumor size (OR 0.99; 95% CI 0.99-0.99), Charlson score (OR 0.92; 95% CI 0.84-0.99), and preoperative RT (OR 1.83; 95% CI 1.61-2.07). Both R0 resection and RT (pre- or post-operative) were associated with increased OS.

CONCLUSIONS

Preoperative RT independently predicts higher rates of R0 resection for patients with extremity STS undergoing surgical resection. Negative surgical margins and pre- or postoperative RT are associated with improved OS.

Nonclinical Profile of BLZ-100, a Tumor-Targeting Fluorescent Imaging Agent

BLZ-100 is a single intravenous use, fluorescent imaging agent that labels tumor tissue to enable more complete and precise surgical resection. It is composed of a chlorotoxin peptide covalently bound to the near-infrared fluorophore indocyanine green. BLZ-100 is in clinical development for intraoperative visualization of human tumors. The nonclinical safety and pharmacokinetic (PK) profile of BLZ-100 was evaluated in mice, rats, canines, and nonhuman primates (NHP). Single bolus intravenous administration of BLZ-100 was well tolerated, and no adverse changes were observed in cardiovascular safety pharmacology, PK, and toxicology studies in rats and NHP. The single-dose no-observed-adverse-effect-levels (NOAELs) were 7 mg (28 mg/kg) in rats and 60 mg (20 mg/kg) in NHP, corresponding to peak concentration values of 89 400 and 436 000 ng/mL and area-under-the-curve exposure values of 130 000 and 1 240 000 h·ng/mL, respectively. Based on a human imaging dose of 3 mg, dose safety margins are >100 for rat and monkey. BLZ-100 produced hypersensitivity reactions in canine imaging studies (lethargy, pruritus, swollen muzzle, etc). The severity of the reactions was not dose related. In a follow-up study in dogs, plasma histamine concentrations were increased 5 to 60 minutes after BLZ-100 injection; this coincided with signs of hypersensitivity, supporting the conclusion that the reactions were histamine based. Hypersensitivity reactions were not observed in other species or in BLZ-100 human clinical studies conducted to date. The combined imaging, safety pharmacology, PK, and toxicology studies contributed to an extensive initial nonclinical profile for BLZ-100, supporting first-in-human clinical trials.

Individualised risk assessment for local recurrence and distant metastases in a retrospective transatlantic cohort of 687 patients with high-grade soft tissue sarcomas of the extremities: a multistate model

OBJECTIVES

This study investigates the effect of surgical margins and radiotherapy, in the presence of individual baseline characteristics, on survival in a large population of high-grade soft tissue sarcoma of the extremities using a multistate model.

DESIGN

A retrospective multicentre cohort study.

SETTING

4 tertiary referral centres for orthopaedic oncology.

PARTICIPANTS

687 patients with primary, non-disseminated, high-grade sarcoma only, receiving surgical treatment with curative intent between 2000 and 2010 were included.

MAIN OUTCOME MEASURES

The risk to progress from 'alive without disease' (ANED) after surgery to 'local recurrence' (LR) or 'distant metastasis (DM)/death'. The effect of surgical margins and (neo)adjuvant radiotherapy on LR and overall survival was evaluated taking patients' and tumour characteristics into account.

RESULTS

The multistate model underlined that wide surgical margins and the use of neoadjuvant radiotherapy decreased the risk of LR but have little effect on survival. The main prognostic risk factors for transition ANED to LR are tumour size (HR 1.06; 95% CI 1.01 to 1.11 (size in cm)) and (neo)adjuvant radiotherapy. The HRs for patients treated with adjuvant or no radiotherapy compared with neoadjuvant radiotherapy are equal to 4.36 (95% CI 1.34 to 14.24) and 14.20 (95% CI 4.14 to 48.75), respectively. Surgical resection margins had a protective effect for the occurrence of LR with HRs equal to 0.61 (95% CI 0.33 to 1.12), and 0.16 (95% CI 0.07 to 0.41) for margins between 0 and 2 mm and wider than 2 mm, respectively. For transition ANED to distant metastases/Death, age (HR 1.64 (95% CI 0.95 to 2.85) and 1.90 (95% CI 1.09 to 3.29) for 25-50 years and >50 years, respectively) and tumour size (1.06 (95% CI 1.04 to 1.08)) were prognostic factors.

CONCLUSIONS

This paper underlined the alternating effect of surgical margins and the use of neoadjuvant radiotherapy on oncological outcomes between patients with different baseline characteristics. The multistate model incorporates this essential information of a specific patient's history, tumour characteristics and adjuvant treatment modalities and allows a more comprehensive prediction of future events.

Prognostic Factors in Indian Patients Operated for Soft Tissue Sarcomas-a Retrospective Cross-sectional Analysis

Soft tissue sarcomas are a rare entity. While surgery is established as the mainstay of treatment, the exact role and sequencing of adjuvant therapy is not well defined. Literature on Indian patients with soft tissue sarcoma with respect to clinical profile and prognostic factors is scarce. We retrospectively analysed the data of 112 patients operated for soft tissue sarcoma of extremity or trunk (excluding retroperitoneal and mediastinal sarcomas, round cell histology) at our institute from 1 January 2009 to 31 December 2013. Around half the patients were less than 50 years of age and around a third had size more than 10 cm. Oncological outcome was correlated with various demographic, tumour-related and treatment-related factors using SPSS 22. Overall survival at 5 years was 73.2 % and event-free survival at 5 years was 42.2 %. At final follow-up (mean of 44.85 ± 4.64 months), local recurrence was seen in 31.9 % and distant metastasis was seen in 30.1 % of the patients. Using both univariate and multivariate analysis, younger age (<50 years), larger size (>10 cm, but not >5 cm) and pathologically positive lymph nodes were the only factors found significantly affecting overall survival. The clinical profile and prognosis of Indian patients with soft tissue sarcoma were found to be different from that reported in Western literature. The impact of established prognostic indicators for soft tissue sarcoma also differed in Indian patients, which may have both prognostic and therapeutic implications.

[Brachytherapy for sarcomas]

The standard of care for local treatment for extremities soft tissue sarcomas relies on conservative surgery combined with external beam radiotherapy. Brachytherapy can be realized instead of external beam radiotherapy in selected cases, or more often used as a boost dose on a limited volume on the area at major risk of relapse, especially if a microscopic positive resection is expected. Close interaction and communication between radiation oncologists and surgeons are mandatory at the time of implantation to limit the risk of side effects. Long-term results are available for low-dose rate brachytherapy. Nowadays, pulsed dose rate or high-dose-rate brachytherapy are more often used. Brachytherapy for paediatric sarcomas is rare, and has to be managed in reference centres.

Intraoperative Raman spectroscopy of soft tissue sarcomas

BACKGROUND AND OBJECTIVE

Soft tissue sarcomas (STS) are a rare and heterogeneous group of malignant tumors that are often treated through surgical resection. Current intraoperative margin assessment methods are limited and highlight the need for an improved approach with respect to time and specificity. Here we investigate the potential of near-infrared Raman spectroscopy for the intraoperative differentiation of STS from surrounding normal tissue.

MATERIALS AND METHODS

In vivo Raman measurements at 785 nm excitation were intraoperatively acquired from subjects undergoing STS resection using a probe based spectroscopy system. A multivariate classification algorithm was developed in order to automatically identify spectral features that can be used to differentiate STS from the surrounding normal muscle and fat. The classification algorithm was subsequently tested using leave-one-subject-out cross-validation.

RESULTS

With the exclusion of well-differentiated liposarcomas, the algorithm was able to classify STS from the surrounding normal muscle and fat with a sensitivity and specificity of 89.5% and 96.4%, respectively.

CONCLUSION

These results suggest that single point near-infrared Raman spectroscopy could be utilized as a rapid and non-destructive surgical guidance tool for identifying abnormal tissue margins in need of further excision. Lasers Surg. Med. 48:774-781, 2016. © 2016 Wiley Periodicals, Inc.

Preclinical Validation of the Utility of BLZ-100 in Providing Fluorescence Contrast for Imaging Spontaneous Solid Tumors

There is a need in surgical oncology for contrast agents that can enable real-time intraoperative visualization of solid tumors that can enable complete resections while sparing normal surrounding tissues. The Tumor Paint agent BLZ-100 is a peptide-fluorophore conjugate that can specifically bind solid tumors and fluoresce in the near-infrared range, minimizing light scatter and signal attenuation. In this study, we provide a preclinical proof of concept for use of this imaging contrast agent as administered before surgery to dogs with a variety of naturally occurring spontaneous tumors. Imaging was performed on excised tissues as well as intraoperatively in a subset of cases. Actionable contrast was achieved between tumor tissue and surrounding normal tissues in adenocarcinomas, squamous cell carcinomas, mast cell tumors, and soft tissue sarcomas. Subcutaneous soft tissue sarcomas were labeled with the highest fluorescence intensity and greatest tumor-to-background signal ratio. Our results establish a foundation that rationalizes clinical studies in humans with soft tissue sarcoma, an indication with a notably high unmet need.

Sarcopenia Does Not Affect Survival or Outcomes in Soft-Tissue Sarcoma

Background and Objective. Sarcopenia is associated with decreased survival and increased complications in carcinoma patients. We hypothesized that sarcopenic soft-tissue sarcoma (STS) patients would have decreased survival, increased incidence of wound complications, and increased length of postresection hospital stay (LOS). Methods. A retrospective, single-center review of 137 patients treated surgically for STS was conducted. Sarcopenia was assessed by measuring the cross-sectional area of bilateral psoas muscles (total psoas muscle area, TPA) at the level of the third lumbar vertebrae on a pretreatment axial computed tomography scan. TPA was then adjusted for height (cm²/m²). The association between height-adjusted TPA and survival was assessed using Cox proportional hazard model. A logistical model was used to assess the association between height-adjusted TPA and wound complications. A linear model was used to assess the association between height-adjusted TPA and LOS. Results. Height-adjusted TPA was not an independent predictor of overall survival (p = 0.746). Patient age (p = 0.02) and tumor size (p = 0.009) and grade (p = 0.001) were independent predictors of overall survival. Height-adjusted TPA was not a predictor of increased hospital LOS (p = 0.66), greater incidence of postoperative infection (p = 0.56), or other wound complications (p = 0.14). Conclusions. Sarcopenia does not appear to impact overall survival, LOS, or wound complications in patients with STS.

Near-infrared autofluorescence spectroscopy of in vivo soft tissue sarcomas

Soft tissue sarcomas (STS) are a rare and heterogeneous group of malignant tumors that are often treated via surgical resection. Inadequate resection can lead to local recurrence and decreased survival rates. In this study, we investigate the hypothesis that near-infrared (NIR) autofluorescence can be utilized for tumor margin analysis by differentiating STS from the surrounding normal tissue. Intraoperative in vivo measurements were acquired from 30 patients undergoing STS resection and were characterized to differentiate between normal tissue and STS. Overall, normal muscle and fat were observed to have the highest and lowest autofluorescence intensities, respectively, with STS falling in between. With the exclusion of well-differentiated liposarcomas, the algorithm's accuracy for classifying muscle, fat, and STS was 93%, 92%, and 88%, respectively. These findings suggest that NIR autofluorescence spectroscopy has potential as a rapid and nondestructive surgical guidance tool that can inform surgeons of suspicious margins in need of immediate re-excision.

Does postoperative infection after soft tissue sarcoma resection affect oncologic outcomes?

BACKGROUND AND OBJECTIVES

Prior studies have demonstrated postoperative infection may confer a survival benefit after osteosarcoma resection. Our aim was to determine whether infection after soft tissue sarcoma resection has similar effects on metastasis, recurrence and survival.

METHODS

A retrospective review was conducted; 396 patients treated surgically for a soft tissue sarcoma between 2000 and 2008 were identified. Relevant oncologic data were collected. Fifty-six patients with a postoperative infection were compared with 340 patients without infection. Hazard ratios and overall cumulative risk were evaluated.

RESULTS

There was no difference in survival, local recurrence or metastasis between patients with or without a postoperative infection. Patients were evenly matched for age at diagnosis, gender, smoking status, and diabetes status. Tumor characteristics did not differ between groups in tumor size, location, depth, grade, margin status, stage, and histologic subtype. There was no difference in utilization of chemotherapy or radiation therapy between groups. From our competing risk model, only positive margin status significantly impacted the risk of local recurrence. An increase in tumor size corresponded to an increased risk of metastasis and death.

CONCLUSIONS

Postoperative infection neither conferred a protective effect, nor increased the risk of adverse oncologic outcomes after soft tissue sarcoma resection.