Clinical significance of margin status in postoperative radiotherapy for extremity and truncal soft-tissue sarcoma

Impact of resection margin on outcome in soft-tissue sarcomas of the extremities treated with limb-sparing surgery and postoperative radiotherapy

BACKGROUND

The standard curative treatments for extremity soft tissue sarcoma (ESTS) include surgical resection with negative margins and perioperative radiotherapy. However, the optimal resection margin remains controversial. This study aimed to evaluate the outcomes in ESTS between microscopically positive margin (R1) and microscopically negative margin (R0) according to the Union for International Cancer Control (UICC) (R + 1 mm) classification.

METHODS

Medical records of patients with localized ESTS who underwent primary limb-sparing surgery and postoperative radiotherapy between 2004 and 2015 were retrospectively reviewed. Patients were followed for at least 5 years or till local or distant recurrence was diagnosed during follow-up. Outcomes were local and distal recurrences and survival.

RESULTS

A total of 52 patients were included in this study, in which 17 underwent R0 resection and 35 underwent R1 resection. No significant differences were observed in rates of local recurrence (11.4% vs. 35.3%, p = 0.062) or distant recurrence (40.0% vs. 41.18%, p = 0.935) between R0 and R1 groups. Multivariate analysis showed that distant recurrences was associated with a Fédération Nationale des Centres de Lutte Contre le Cancer (FNCLCC) grade (Grade III vs. I, adjusted hazard ratio (aHR): 12.53, 95% confidence interval (CI): 2.67-58.88, p = 0.001) and tumor location (lower vs. upper extremity, aHR: 0.23, 95% CI: 0.07-0.7, p = 0.01). Kaplan-Meier plots showed no significant differences in local (p = 0.444) or distant recurrent-free survival (p = 0.161) between R0 and R1 groups.

CONCLUSIONS

R1 margins, when complemented by radiotherapy, did not significantly alter outcomes of ESTS as R0 margins. Further studies with more histopathological types and larger cohorts are necessary to highlight the path forward.

Special Issue: "Pediatric Orthopedic Malignancy: Types, Symptoms, and Treatment"

Pediatric orthopedic malignancies are extremely rare and require appropriate diagnosis and treatment by a multidisciplinary team [...].

Adult Soft-Tissue Sarcomas of the Extremities

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Soft-tissue sarcomas (STS) in adults comprise a heterogeneous group of tumors of mesenchymal origin that share similar biological patterns of local tumor growth and metastatic dissemination.

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The judicious use of imaging studies, biopsy techniques, and pathological evaluations is essential for accurate diagnosis and for planning treatment strategy.

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Wide local resection and radiation therapy form the cornerstone of management of high-grade STS. The role of adjuvant radiation therapy is questionable in the management of small (≤5 cm) superficial lesions that can be resected with negative margins. Chemotherapy given to patients who have nonmetastatic, high-grade STS results in varying benefit in terms of local tumor control and overall survival.

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Coordinated care by a multidisciplinary team of trained surgeons, medical oncologists, radiologists, radiation oncologists, and pathologists has been documented to improve local tumor control and the overall survival of patients with STS.

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Although considerable progress in tumor diagnostics and targeted therapies has been made over the past 2 decades, recommendations and controversies relating to tumor imaging and margins of resection have not changed.

Margin Assessment in Soft Tissue Sarcomas: Review of the Literature

Simple Summary

Many classifications to assess margins status for soft tissue sarcomas are reported in the literature. Most of the series are heterogeneous and variable in size, making it difficult to compare results from study to study. Thus, which is the best way to assess margins in order to predict the risk of local recurrence is still debated. The aim of this narrative review is to provide a comprehensive assessment of the literature on margins, and to highlight the need for a uniform description of the margin status for patients with soft tissue sarcomas (STS).

Abstract

Adequacy of margins must take into consideration both the resection margin width (quantity) and anatomic barrier (quality). There are several classification schemes for reporting surgical resection margin status for soft tissue sarcomas (STS). Most of the studies regarding treatment outcomes in STS included all histologic grades and histological subtypes, which include infiltrative and non-infiltrative subtypes and are very heterogeneous in terms of both histologic characteristics and treatment modalities (adjuvant treatments or not). This lack of consistency makes it difficult to compare results from study to study. Therefore, there is a great need for evidence-based standardization concerning the width of resection margins. The aim of this narrative review is to provide a comprehensive assessment of the literature on margins, and to highlight the need for a uniform description of the margin status for patients with STS. Patient cases should be discussed at multidisciplinary tumor boards and treatments should be individualized to clinical and demographic characteristics, which must include also a deep knowledge of specific histotypes behaviors, particularly infiltrative ones.

Sarcoma treatment in the era of molecular medicine

Sarcomas are heterogeneous and clinically challenging soft tissue and bone cancers. Although constituting only 1% of all human malignancies, sarcomas represent the second most common type of solid tumors in children and adolescents and comprise an important group of secondary malignancies. More than 100 histological subtypes have been characterized to date, and many more are being discovered due to molecular profiling. Owing to their mostly aggressive biological behavior, relative rarity, and occurrence at virtually every anatomical site, many sarcoma subtypes are in particular difficult-to-treat categories. Current multimodal treatment concepts combine surgery, polychemotherapy (with/without local hyperthermia), irradiation, immunotherapy, and/or targeted therapeutics. Recent scientific advancements have enabled a more precise molecular characterization of sarcoma subtypes and revealed novel therapeutic targets and prognostic/predictive biomarkers. This review aims at providing a comprehensive overview of the latest advances in the molecular biology of sarcomas and their effects on clinical oncology; it is meant for a broad readership ranging from novices to experts in the field of sarcoma.

The Effect of Resection Margin on Local Recurrence and Survival in High Grade Soft Tissue Sarcoma of the Extremities: How Far Is Far Enough?

Simple Summary

In soft tissue sarcomas the width of surgical margins after resection determines the extent of surgery and the function after resection. But how far is really necessary? 305 patients with deep-seated, G2/3 soft tissue sarcomas of the extremity, the trunk wall, or the pelvis were reviewed. The 5-year local recurrence-free survival (LRFS) was 82%. Overall survival (OS) at 5 years was 66%. Positive (contaminated) margins worsened LRFS and OS. A margin of >10 mm did not improve LRFS and OS as compared to one of >5 mm. A resection margin of <1 mm showed a trend but not significantly better LRFS or OS compared to a contaminated margin. In conclusion the margin should at least be free of tumor, in sound tissue. A margin of >5 mm sound tissue seems to be sufficient. Resecting more tissue does not benefit the patient.

Abstract

Background: The significance of surgical margins after resection of soft tissue sarcomas in respect to local-recurrence-free survival and overall survival is evaluated. Methods: A total of 305 patients with deep-seated, G2/3 soft tissue sarcomas (STS) of the extremity, the trunk wall, or the pelvis were reviewed. The margin was defined according to the Fédération Nationale des Centres de Lutte Contre le Cancer (FNCLCC) classification system (R0-2), the Union Internationale Contre le Cancer (UICC) classification (R + 1 mm) for which a margin <1 mm is included into the R1 group, and in groups of <1 mm, 1–5 mm, >5 mm, or >10 mm. Results: Of these patients, 31 (10.2%) had a contaminated margin, 64 (21%) a margin of <1 mm, 123 (40.3%) a margin of 1–5 mm, 47 (15.4%) a margin of >5 mm, and 40 (13.1%) a margin of >10 mm. The 5-year local recurrence-free survival (LRFS) was 81.6%. Overall survival (OS) at 5 years was 65.9%. Positive margins worsened LRFS and OS. A margin of >10 mm did not improve LRFS and OS as compared to one of >5 mm. Conclusions: A resection margin of <1 mm showed a trend but not significantly better LRFS or OS compared to a contaminated margin. This finding supports use of the UICC classification. A margin of more than 10 mm did not improve LRFS or OS.

The adequacy of resection margin for non-infiltrative soft-tissue sarcomas

OBJECTIVES

There remains no consensus on what constitutes an adequate margin of resection for non-infiltrative soft-tissue sarcomas (STSs). We aimed to investigate the role of resection margins in millimetres for non-infiltrative STSs.

METHODS

502 patients who underwent surgical resection for a localized, non-infiltrative, high-grade STSs were studied. The prognostic significance of margin width was analysed and compared with the conventional R- and R+1-classification of surgical margins.

RESULTS

The overall local recurrence (LR) rate was 13%; 9% and 27% with negative and positive margins, respectively (p < 0.001). In patients with negative margins, the LR rates were greater than 10% in patients with margins ≤5.0 mm but reduced to less than 4% with margins >5.0 mm. When classified by the R- (or R+1)-classification, the 5-year cumulative LR incidence was 8%, 23% (16%), and 31% for R0, R1, and R2, respectively, which did not stratify the LR risk with negative margins. On the other hand, an accurate risk stratification was possible by metric distance; the 5-year cumulative incidence of LR was 29%, 10%, and 1% with 0 mm, 0.1-5.0 mm, and >5.0 mm, respectively (p < 0.001). This classification also stratified the LR risk in patients with or without adjuvant radiotherapy.

CONCLUSION

While a negative margin is essential to optimize local control in patients with non-infiltrative STSs, surgical margin width greater than 5 mm minimises the risk of local failure regardless of the use of adjuvant radiotherapy.

Multidisciplinary treatment of soft tissue sarcomas: An update

Standard treatment for soft tissue sarcoma, based on complete surgical resection with or without adjuvant radiotherapy and chemotherapy, has not substantially changed during the last several decades. Nevertheless, recent advances have contributed to considerable improvement in the management of these patients; for example, new magnetic resonance imaging sequences such as diffusion-weighted imaging and magnetic resonance imaging radiomics can better assess tumor extension and even estimate its grade. Detection of circulating genetic material (liquid biopsy) and next-generation sequencing are powerful techniques for genetic analysis, which will increase our understanding of the underlying molecular mechanisms and may reveal potential therapeutic targets. The role of chemotherapy in non-metastatic disease is still controversial, and there is a need to identify patients who really benefit from this treatment. Novel chemotherapeutic regimens have entered clinical praxis and can change the outcome of patients with metastatic disease. Advances in radiotherapy have helped decrease local adverse effects and sustain good local control of the disease. The following report provides an updated view of the diagnosis, treatment, and future perspectives on the management of patients with soft tissue sarcomas.

Surgical resection margin classifications for high-grade pleomorphic soft tissue sarcomas of the extremity or trunk: definitions of adequate resection margins and recommendations for sampling margins from primary resection specimens

Adequacy of surgical resection margins for soft tissue sarcomas are poorly defined because of the various classifications and definitions used in prior studies of heterogeneous patient cohorts and inconsistent margin sampling protocols. Surgical resection margins of 166 primary, high-grade, pleomorphic sarcomas of the extremity or trunk were classified according to American Joint Committee on Cancer R and Musculoskeletal Tumor Society categories, as well as by metric distance and tissue composition. None of the cases were treated with neoadjuvant therapy. Multivariable competing risk regression models were evaluated and optimal surgical resection margins for each classification system were defined. Minimum safe tumor clearance was 5 mm without use of adjuvant radiotherapy and 1 mm with adjuvant radiotherapy. Predictive accuracy of margin classification systems was compared by area under receiver-operating characteristic curves generated from logistic regression of 2½-year local recurrence-free survival and other standard tests of diagnostic accuracy. The Musculoskeletal Tumor Society and margin distance classifications performed similarly, both of which showed higher sensitivity and negative predictive value compared to the American Joint Committee on Cancer R classification. The prognostic power of close or positive margins in prediction models significantly increased when six or more slides were submitted for assessment of surgical resection margins. Surgical resection margins for soft tissue sarcoma should be reported using the Musculoskeletal Tumor Society classification or metric distance to the closest resection margin. Musculoskeletal Tumor Society wide/radical margins or tumor clearances of 5 mm (without adjuvant radiotherapy) or 1 mm (with adjuvant radiotherapy) appear to define the minimum safe surgical resection margins necessary to decrease the likelihood of local recurrence of high-grade pleomorphic sarcomas of the extremity or trunk.

The role of radiation therapy and margin width in localized soft-tissue sarcoma: Analysis from the US Sarcoma Collaborative

BACKGROUND AND OBJECTIVES

Soft-tissue sarcomas (STSs) are often treated with resection and radiation (RT)±chemotherapy. The role of RT in decreasing resection width to achieve local control is unclear. We evaluated RT on margin width to achieve local control and local recurrence (LR).

METHODS

From 2000 to 2016, 514 patients with localized STS were identified from the US Sarcoma Collaborative database. Patients were stratified by a margin and local control was compared amongst treatment groups.

RESULTS

LR was 9% with positive, 4.2% with ≤1 mm, and 9.3% with >1 mm margins (P = .315). In the ≤1 mm group, LR was 5.7% without RT, 0% with preoperative RT, and 0% with postoperative RT (P < .0001). In the >1 mm group, LR was 10.2%, 0%, and 3.7% in the no preoperative and postoperative RT groups, respectively (P = .005). RT did not influence LR in patients with positive margins. In stage I-III and II-III patients, local recurrence-free survival was higher following RT (P = .008 and P = .05, respectively).

CONCLUSIONS

RT may play a larger role in minimizing LR than margin status. In patients with positive margins, RT may decrease LR to similar rates as a negative margin without RT and may be considered to decrease the risk of LR with anticipated close/positive margins.

[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.

The Width of the Surgical Margin Does Not Influence Outcomes in Extremity and Truncal Soft Tissue Sarcoma Treated With Radiotherapy

BACKGROUND AND OBJECTIVES

It is unclear whether the quantitative width of the surgical margin influences outcomes in patients with extremity and truncal soft tissue sarcoma (STS) treated with radiotherapy (RT).

METHODS

We performed a retrospective review of 382 patients with localized extremity or truncal STS who underwent limb-sparing surgery and RT from 1983 to 2010, and we analyzed the significance of resection margin status and quantitative margin width on outcomes.

RESULTS

Surgical margins were positive in 68 (18%) patients and negative in 314 (82%) patients. For those patients with a reported quantitative margin width (n = 235), the width of the negative margin was ≤1 mm (n = 128), >1 mm and ≤5 mm (n = 79), and >5 mm (n = 28). At a median follow-up of 82 months, the local recurrence rates were 5.4% and 11.8% for margin-negative and margin-positive patients, respectively. There were no differences in the rates of local or distant recurrence nor of any survival outcome based on the quantitative width of the surgical margin, provided that it was negative.

CONCLUSIONS

In patients undergoing RT and limb-sparing surgery for STS, achieving a negative margin is essential for optimizing both local control and survival. However, the absolute quantitative width of the negative margin does not significantly influence outcome, and so attempts at wide margins of resection appear to be unnecessary. Importantly, the conclusions drawn from this study must not be applied to those patients undergoing surgery alone as the local treatment of their STS, in which case wider margins of resection may be necessary.

IMPLICATIONS FOR PRACTICE

In patients undergoing radiation therapy and limb-sparing surgery for soft tissue sarcoma, the quantitative width of the negative margin does not influence outcome, and so attempts at wide margins of resection appear to be unnecessary, especially when such attempts compromise the functional outcome. Importantly, the conclusions drawn from this study must not be applied to those patients undergoing surgery alone as the local treatment of their soft tissue sarcoma, in which case wider margins of resection may be necessary.

The role of margins in extremity soft tissue sarcoma

For extremity soft tissue sarcomas, limb salvage is now standard of care. The extent of surgical margins is balanced with functionality of the resected limb. Although negative margins are the goal, the necessary width is unclear. Additional considerations for margin adequacy include presence of anatomic barriers such as fascia and periosteum, proximity of critical structures, receipt of adjuvant and neoadjuvant therapies, and histologic subtype. Multidisciplinary team discussion is critical for treatment planning.

Unplanned Excision of Extremity Soft Tissue Sarcoma in Korea: A Nationwide Study Based on a Claims Registry

Unplanned excision of extremity soft tissue sarcoma (STS) is common and has detrimental effects not only on patients’ oncologic outcomes but also on functional and economic issues. However, no study has analyzed a nationwide population-based database. To estimate the incidence and treatment pattern of unplanned excision in extremity STS in the Korean population, a nationwide epidemiologic study was performed using the Korean Health Insurance Review and Assessment Service database, a centralized nationwide healthcare claims registry of Korea that covers the entire Korean population. Among 1,517 patients with extremity STS in the 4-year study period, 553 (36.5%) underwent unplanned excision (unplanned group). About 80% of unplanned excisions were performed in tertiary or general hospitals. Of the unplanned group, 240 (43.4%) underwent re-excision with or without radiation therapy and/or chemotherapy, and 51 (9.2%) did not undergo re-excision but were treated with radiation therapy and/or chemotherapy; whereas, 262 (47.4%) did not undergo any further treatment following unplanned excision. This study is the first nationwide population-based study on the unplanned excision of extremity STS. The results may have implications in establishing preventive or therapeutic measures to reduce the burden of unplanned excision of extremity STS.

Improvement in Overall Survival from Extremity Soft Tissue Sarcoma over Twenty Years

Several patient demographic factors, including marital status, have been demonstrated to have prognostic significance for survival in extremity soft tissue sarcoma (ESTS). A study population of 12,546 adult patients diagnosed with ESTS from 1991 to 2010 was identified from the SEER database, a large population-based registry, in order to determine whether overall survival had changed over this recent 20-year period. The study population was divided into three groups by year of diagnosis: 1991–1996, 1997–2003, and 2004–2010. We used the Kaplan-Meier method and Cox proportional hazards regression to assess survival differences between different demographic groups and prognostic clinical characteristics. Over the course of time, the 5-year overall survival rates have increased from 28% in the earliest time period to 62% in the latest (P < 0.0001). On multivariate analysis, the mortality rate progressively declined from the 1991–1996 group (HR: 3.02, CI: 2.78–3.29) to the 1997–2003 group (HR: 2.21, CI: 2.06–2.37), with the 2004–2010 group having the best overall survival, despite increases in the proportion of patients with tumors greater than 5 cm in size (P < 0.0001), and those presenting with metastasis (P < 0.0001).

Postoperative radiation boost does not improve local recurrence rates in extremity soft tissue sarcomas

INTRODUCTION

The standard of care for extremity soft tissue sarcomas continues to be negative-margin limb salvage surgery. Radiotherapy is frequently used as an adjunct to decrease local recurrence. No differences in survival have been found between preoperative and postoperative radiotherapy regimens. However, it is uncertain if the use of a postoperative boost in addition to preoperative radiotherapy reduces local recurrence rates.

METHODS

This retrospective review evaluated patients who received preoperative radiotherapy (n = 49) and patients who received preoperative radiotherapy with a postoperative boost (n = 45). The primary endpoint analysed was local recurrence, with distant metastasis and death due to sarcoma analysed as secondary endpoints. Wilcoxon rank-sum test and either χ(2) or Fisher's exact test were used to compare variables. Multivariable regression analyses were used to take into account potential confounders and identify variables that affected outcomes.

RESULTS

No differences in the proportion or rate of local recurrence, distant metastasis or death due to sarcoma were observed between the two groups (P > 0.05). The two groups were similarly matched with respect to demographics such as age, race and sex and tumour characteristics including excision status, tumour site, size, depth, grade, American Joint Committee on Cancer stage, chemotherapy receipt and histological subtype (P > 0.05). The postoperative boost group had a larger proportion of patients with positive microscopic margins (62% vs 10%; P < 0.001).

CONCLUSION

No differences in rates of local recurrence, distant metastasis or death due to sarcoma were found in patients who received both pre- and postoperative radiotherapy when compared with those who received only preoperative radiotherapy.

Surgical margins and handling of soft-tissue sarcoma in extremities: a clinical practice guideline

QUESTIONS

In limb salvage surgery for extremity soft-tissue sarcoma (sts), what is an adequate surgical margin?What is the appropriate number of samples to take from the margins of a surgical resection specimen?What is the appropriate handling of surgical resection specimens?

BACKGROUND

Surgery is the primary treatment for extremity sts. The combination of radiotherapy with surgery allows for limb salvage by using radiation to biologically "sterilize" microscopic extensions of tumour and to spare neurovascular and osseous structures. Adjuvant chemotherapy in sts-except for rhabdomyosarcoma and Ewing sarcoma-continues to be controversial.

METHODS

The medline and embase databases (1975 to June 2011) and the Cochrane Library were searched for pertinent studies. The Web sites of the main guideline organizations and the American Society of Clinical Oncology conference proceedings (2007-2010) were also searched.

RESULTS AND CONCLUSIONS

Thirty-three papers, including four guidelines, one protocol, and one abstract, were eligible for inclusion. The data suggest that patients with clear margins have a better prognosis, but no prospective studies have indicated how wide margins should be. In limb-salvage surgery for extremity sts, the procedure should be planned to achieve a clear margin. However, to preserve functionality, surgery may result in a very close (<1 cm) or even microscopically positive margin. In this circumstance, the use of preoperative or postoperative radiation should be considered. No studies described the optimal number of tissue sections required to assess adequacy of excision nor the appropriate handling of surgical resection specimens. The Sarcoma Disease Site Group made its recommendations based on expert opinion and consensus.

The significance of close but negative excision margin for treatment of soft-tissue sarcoma

Wide excision is the major recommendation for management of soft-tissue sarcomas. Pathologic reports of postexcision sarcomas revealed very close (within 2 mm) but clear excision margins. This investigation was a retrospective study to determine whether wide reexcision plus radiotherapy (R/T), or R/T only, yielded better outcomes.

MATERIALS AND METHODS

We evaluated our soft-tissue sarcoma cases who had received wide excision in the past 15 years. The surgical margin conditions (negative, positive, or close margins) and pathologic status were evaluated. The different management modalities for each condition were also evaluated individually and discussed.

RESULTS

There were 73 cases from 1995 to 2010 in our section who had received wide excision. The overall recurrence rate was 24.6%. In cases with margin positive, the recurrence rate was 20% (2/8) after quick reexcision. However, the recurrence rate was 56% in patients who received R/T but without quick reexcision. In cases with close resection margins (<2 mm) with no reexcision but R/T, the recurrence rate was 45%, and all of them had a high-grade malignancy sarcoma. The other nonrecurrence cases (55%) had low-grade malignancy or well-differentiated sarcoma.In summary, in cases with positive margin sarcoma, quick reexcision plus R/T was suggested and the recurrence rate was relatively low. In soft-tissue sarcoma cases with close margin, we believe quick reexcision plus R/T is necessary, especial in high-grade, poor differentiated soft-tissue sarcomas.

Risk factors for local recurrence and metastasis in soft tissue sarcomas of the extremity

OBJECTIVES

We reviewed our institution's experience in treating soft tissue sarcomas of the extremity to identify factors associated with local recurrence, metastasis, and overall survival, to identify patients who may benefit from intensification of therapy.

METHODS

A retrospective analysis was performed for patients who underwent both limb-sparing surgery and external beam radiotherapy for extremity sarcoma. Those who had gross residual disease or who presented with recurrent or metastatic disease were excluded. The Kaplan-Meier product limit and multivariate Cox regression were used to estimate local failure-free probability, distant failure-free probability, and overall survival along with associations with patient, tumor, and treatment characteristics.

RESULTS

One hundred eighty-eight patients were included in the analysis. Twenty-five (13%) and 46 (24%) experienced local and distant recurrence, respectively. Patients with high/intermediate-grade tumors [hazard ratio (HR)=5.63, 95% confidence interval (CI): 1.27-24.89, P=0.023] or with multifocally positive margins (HR=4.27, 95% CI: 1.20-15.24, P=0.026) were more likely to fail locally. Those with a preceding local recurrence (HR=8.58, 95% CI: 3.87-19.04, P<0.0001), high/intermediate-grade tumors (HR=5.68, 95% CI: 1.28-25.25, P=0.023), or no secondary reexcision (HR=2.5, 95% CI: 1.09-5.74, P=0.031) were more likely to develop metastasis. Patients with local recurrence (HR=3.6, 95% CI: 1.77-7.29, P<0.001), metastasis (HR=16.0, 95% CI: 7.93-32.31, P<0.0001), or without secondary reexcision (HR=3.2, 95% CI: 1.27-8.09, P=0.014) had decreased overall survival.

CONCLUSIONS

Patients whose tumor grade or margin status put them at high risk for local failure should be considered for intensification of therapy. Those with a local recurrence should be considered for increased surveillance or systemic therapy, as local failure is associated with subsequent metastasis and decreased survival.

Extremity soft tissue sarcoma resections: how wide do you need to be?

BACKGROUND

Sarcomas require a wide margin of resection including a cuff of normal tissue to minimize the risk of local recurrence. The amount of tissue that constitutes a wide margin is unclear in the literature.

QUESTIONS/PURPOSES

We therefore determined whether a close resection margin for soft tissue sarcoma resulted in an increased incidence of locally recurrent disease and whether additional factors, including radiation therapy, outside biopsies, and tumor biology, affected the risk of local recurrence.

METHODS

We retrospectively reviewed 117 patients with soft tissue sarcomas resected with negative margins from 2001 to 2007. Gross specimens were inked and the closest macroscopic margins were sent for microscopic examination. Resection margins were categorized as less than 1 mm, 1-5 mm, or greater than 5 mm. We evaluated additional factors that might influence local recurrence, including radiation therapy, outside biopsies, sarcoma type, grade, and stage at presentation, and development of metastatic disease.

RESULTS

Four of 117 patients (3.4%) developed local recurrence. The incidence of local recurrence was similar in patients with less than 1-mm margins and greater than 1-mm margins: two of 45 patients (4.4%) and two of 64 patients (3.1%), respectively. Due to the low number of local recurrences, quantitative margin extent and the other factors evaluated did not affect local recurrence.

CONCLUSIONS

The extent of a margin necessary to prevent local recurrence of soft tissue sarcoma remains unclear as the power of our study was limited by the low number of local recurrences. Relatively low local recurrence rates can be achieved even with close margins.

LEVEL OF EVIDENCE

Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Perioperative irradiation in extremity soft tissue sarcoma

Adjuvant radiotherapy constitutes an important component of the treatment of soft tissue sarcomas. Extremity soft tissue sarcomas constitute a large proportion of this rare mesenchymal tumor. Questions regarding timing, techniques and toxicity come into play about optimizing adjuvant radiotherapy. This article will discuss recent trends and outcomes of perioperative, that is, preoperative and postoperative, irradiation.

[Particle therapy: carbon ions]

Carbon ion therapy is an innovative radiation therapy. It has been first proposed in the forties by Robert Wilson, however the first dedicated centres for human care have been build up only recently in Japan and Germany. The interest of carbon ion is twofold: 1) the very sharp targeting of the tumour with the so called spread out Bragg peak that delivers most of the beam energy in the tumour and nothing beyond it, sparing very efficiently the healthy tissues; 2) the higher relative biological efficiency compared to X rays or protons, able to kill radioresistant tumour cells. Both properties make carbon ions the elective therapy for non resectable radioresistant tumours loco-regionally threatening. The technical and clinical experience accumulated during the recent decades is summarized in this paper along with a detailed presentation of the elective indications. A short comparison between conventional radiotherapy and hadrontherapy is proposed for the indications which are considered as priority for carbon ions.

Preliminary results from a prospective study using limited margin radiotherapy in pediatric and young adult patients with high-grade nonrhabdomyosarcoma soft-tissue sarcoma

PURPOSE

To demonstrate the safety and efficacy of limited margin radiotherapy in the local control of pediatric and young adult patients with high-grade nonrhabdomyosarcoma soft tissue sarcoma (NRSTS).

METHODS AND MATERIALS

Pediatric patients with high-grade NRSTS requiring radiation were treated on an institutional review board approved prospective institutional study of conformal/intensity-modulated/interstitial brachytherapy using a 2-cm anatomically constrained margin.

RESULTS

A total of 32 patients (median age, 15.3 years; range, 2-22 years) received adjuvant (27 patients) or definitive (5 patients) irradiation. With a median follow-up of 32 months, the 3-year cumulative incidence of local failure was 3.7% for patients undergoing irradiation after surgical resection. Four patients experienced local failure; the mean dose to the volume of recurrence was >or=97% of the prescribed dose.

CONCLUSIONS

Delivery of limited margin radiotherapy using external beam or brachytherapy provides a high rate of local tumor control without marginal failure. Further follow-up is required to determine whether normal tissue effects are minimized using this approach.