NCCN: Continuing Education
Accreditation Statement
This activity has been designated to meet the educational needs of physicians, nurses, and pharmacists involved in the management of patients with cancer. There is no fee for this article. The National Comprehensive Cancer Network (NCCN) is accredited by the ACCME to provide continuing medical education for physicians. NCCN designates this journal-based CE activity for a maximum of 1.0 AMA PRA Category 1 Credit(s)™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.
NCCN is accredited as a provider of continuing nursing education by the American Nurses Credentialing Center‘s Commission on Accreditation.
This activity is accredited for 1.0 contact hour. Accreditation as a provider refers to recognition of educational activities only; accredited status does not imply endorsement by NCCN or ANCC of any commercial products discussed/displayed in conjunction with the educational activity. Kristina M. Gregory, RN, MSN, OCN, is our nurse planner for this educational activity.
National Comprehensive Cancer Network is accredited by the Accreditation Council for Pharmacy Education as a provider of continuing pharmacy education. NCCN designates this continuing education activity for 1.0 contact hour(s) (0.1 CEUs) of continuing education credit in states that recognize ACPE accredited providers. This is a knowledge-based activity. UAN: 0836-0000-14-004-H01-P
All clinicians completing this activity will be issued a certificate of participation. To participate in this journal CE activity: 1) review the learning objectives and author disclosures; 2) study the education content; 3) take the posttest with a 66% minimum passing score and complete the evaluation at http://education.nccn.org/node/43685; and 4) view/print certificate.
Release date: April 11, 2014; Expiration date: April 11, 2015
Learning Objectives:
Upon completion of this activity, participants will be able to:
Integrate into professional practice the updates to NCCN Guidelines for Soft Tissue Sarcoma
Describe the rationale behind the decision-making process for developing the NCCN Guidelines for Soft Tissue Sarcoma
NCCN Categories of Evidence and Consensus
Category 1: Based upon high-level evidence, there is uniform NCCN consensus that the intervention is appropriate.
Category 2A: Based upon lower-level evidence, there is uniform NCCN consensus that the intervention is appropriate.
Category 2B: Based upon lower-level evidence, there is NCCN consensus that the intervention is appropriate.
Category 3: Based upon any level of evidence, there is major NCCN disagreement that the intervention is appropriate.
All recommendations are category 2A unless otherwise noted.
Clinical trials: NCCN believes that the best management for any cancer patient is in a clinical trial. Participation in clinical trials is especially encouraged.
NCCN Guidelines Insights: Soft Tissue Sarcoma, Version 2.2014
Version 2.2014 © National Comprehensive Cancer Network, Inc. 2014, All rights reserved. The NCCN Guidelines® and this illustration may not be reproduced in any form without the express written permission of NCCN®.
Citation: Journal of the National Comprehensive Cancer Network J Natl Compr Canc Netw 12, 4; 10.6004/jnccn.2014.0053
Overview
Soft tissue sarcomas (STS) are a heterogeneous group of rare solid tumors with distinct clinical and pathologic features. In 2014, an estimated 12,020 people will be diagnosed with STS in the United States, and approximately 4740 will die of the disease.1 Genetic cancer syndromes caused by germline mutations in several different genes have been associated with inherited predisposition for the development of STS.2-7
Radiation therapy (RT) and/or chemotherapy are often used as an adjunct to surgery for patients with retroperitoneal/intra-abdominal STS, because the risk of failure in the surgical bed can be high. Newer RT techniques, such as intraoperative RT (IORT) and intensity-modulated RT (IMRT), seem to have led to the improvement of treatment outcomes in patients with retroperitoneal/intra-abdominal STS.
These NCCN Guidelines Insights discuss the role of genetic testing and counseling in patients with genetic cancer syndromes with a predisposition for the development STS and the role of RT in the management of patients with retroperitoneal/intra-abdominal STS.
NCCN Guidelines Insights: Soft Tissue Sarcoma, Version 2.2014
Version 2.2014 © National Comprehensive Cancer Network, Inc. 2014, All rights reserved. The NCCN Guidelines® and this illustration may not be reproduced in any form without the express written permission of NCCN®.
Citation: Journal of the National Comprehensive Cancer Network J Natl Compr Canc Netw 12, 4; 10.6004/jnccn.2014.0053
Genetic Cancer Syndromes With a Predisposition to STS
Li-Fraumeni syndrome (resulting from germline mutations in the TP53 tumor suppressor gene) is characterized by an increased risk of developing multiple primary malignancies, predominantly STS, osteosarcomas, breast cancer, leukemia, brain tumors, and adrenocortical carcinoma before 45 years of age.2,8-10 The incidence of STS ranges from 12% to 21% in individuals with TP53 germline mutations.11-13 In general, STS associated with Li-Fraumeni syndrome are diagnosed at significantly younger ages than the sporadic STS. The mean age at diagnosis, however, varies with histologic subtype. In an analysis of 475 tumors in 91 families with TP53 germline mutations, Kleihues et al11 reported rhabdomyosarcomas, fibrosarcomas, and undifferentiated pleomorphic sarcoma as the most frequent histologic subtypes identified in 55%, 13%, and 10% of patients, respectively. The mean age at diagnosis for rhabdomyosarcomas was younger than 6 years and the mean age at diagnosis was older than 50 years for undifferentiated pleomorphic sarcomas.
Familial adenomatous polyposis (FAP) is an inherited autosomal-dominant colorectal cancer syndrome resulting from germline mutations in the adenomatous polyposis coli (APC) gene on chromosome 5q21.4,6 FAP is characterized by adenomatous colorectal polyps that progress to colorectal cancer at 35 to 40 years of age. Gardner syndrome is considered as a variant of FAP with extracolonic manifestations such as osteomas, skin cysts, congenital hypertrophy of the retinal pigmented epithelium, and desmoid tumors (aggressive fibromatosis).14 Desmoid tumors have been reported to occur in 7.5% to 16% of patients with FAP, and the relative risk of developing desmoid tumors is much higher in patients with FAP than in the general population.15-18 In an International Dutch Cohort study involving 2260 patients with FAP, positive family history for desmoid tumors, abdominal surgery, and the APC mutation site were identified as significant risk factors for the development of desmoid tumors.18 The median age at diagnosis was 31 years, with most desmoid tumors arising in the intra-abdominal and abdominal wall areas (53% and 24%, respectively).
NCCN Guidelines Insights: Soft Tissue Sarcoma, Version 2.2014
Version 2.2014 © National Comprehensive Cancer Network, Inc. 2014, All rights reserved. The NCCN Guidelines® and this illustration may not be reproduced in any form without the express written permission of NCCN®.
Citation: Journal of the National Comprehensive Cancer Network J Natl Compr Canc Netw 12, 4; 10.6004/jnccn.2014.0053
Carney-Stratakis syndrome is an autosomal-dominant familial syndrome characterized by predisposition to gastrointestinal stromal tumors (GIST) and paragangliomas.19 Germline loss-of-function mutations within the SDH gene subunits (SDHB, SDHC, and SDHD) have been identified in individuals with GIST associated with Carney-Stratakis syndrome.20 In an analysis of 11 patients from 9 families presenting with GIST and paragangliomas associated with Carney-Stratakis syndrome, Pasini et al20 identified germline mutations in SDHB, SDHC, or SDHD genes in 8 patients (from 7 untreated families) with GIST. The tumors also lacked activating KIT or PDGFRα mutations associated with sporadic GIST. GIST associated with Carney-Stratakis syndrome is also reported to be negative for SDHB expression by immunohistochemistry (IHC), in contrast to GIST with KIT or PDGFRα mutations or sporadic GIST.21,22 SDHB IHC can be useful for diagnosing Carney-Stratakis syndrome and SDH-deficient GIST.
Genetic Testing and Counseling for Patients With Germline Mutations: NCCN Recommendations
Patients (and their families) with personal and/or family history suggestive of Li-Fraumeni syndrome should be considered for further genetic assessment as outlined in the NCCN Guidelines for Genetic/Familial High-Risk Assessment: Breast and Ovarian Cancers.
SDH gene mutational analysis for the identification of germline mutations in the SDH gene subunits should be considered for patients with GIST lacking KIT or PDGFRα mutations. Loss of SDHB protein expression by IHC is a useful screen to identify patients who would be appropriate for germline mutation testing, but it is not diagnostic of a germline mutation.
Evaluation for family history of FAP or Gardner syndrome is recommended for patients diagnosed with desmoid tumors (aggressive fibromatoses).
NCCN Guidelines Insights: Soft Tissue Sarcoma, Version 2.2014
Version 2.2014 © National Comprehensive Cancer Network, Inc. 2014, All rights reserved. The NCCN Guidelines® and this illustration may not be reproduced in any form without the express written permission of NCCN®.
Citation: Journal of the National Comprehensive Cancer Network J Natl Compr Canc Netw 12, 4; 10.6004/jnccn.2014.0053
Retroperitoneal/Intra-abdominal Soft Tissue Sarcomas: Role of RT
Surgery is the standard treatment for patients with retroperitoneal/intra-abdominal STS. However, complete or macroscopic surgical resection is achieved in fewer than 70% of patients with primary tumors, because of their proximity to vital structures. Multimodality treatment (surgery with RT and/or chemotherapy) is therefore favored because of the inability to obtain negative surgical margins and high local recurrence rates.23
RT can be administered either as preoperative or postoperative treatment for patients with resectable disease, and as a primary treatment for those with unresectable disease. Newer RT techniques such as IMRT and 3-dimensional (3D) conformal RT using protons or photons may allow tumor target coverage and acceptable clinical outcomes within normal tissue dose constraints to adjacent organs at risk.24-27 When external-beam RT is used, sophisticated treatment planning with IMRT, tomotherapy, and/or proton therapy can be used to improve therapeutic effect. However, the safety and efficacy of adjuvant RT techniques have yet to be evaluated in multicenter randomized controlled studies.
NCCN Guidelines Insights: Soft Tissue Sarcoma, Version 2.2014
Version 2.2014 © National Comprehensive Cancer Network, Inc. 2014, All rights reserved. The NCCN Guidelines® and this illustration may not be reproduced in any form without the express written permission of NCCN®.
Citation: Journal of the National Comprehensive Cancer Network J Natl Compr Canc Netw 12, 4; 10.6004/jnccn.2014.0053
Preoperative RT
Preoperative RT is often preferred because it reduces the risk of tumor seeding at the time of surgery and may render tumors more amenable to resection.28 Long-term results of 2 prospective studies showed favorable 5-year local relapse-free survival (RFS), disease-free survival (DFS), and overall survival (OS) rates (60%, 46%, and 61%, respectively) following R0 or R1 resection after preoperative RT in patients with intermediate- or high-grade retroperitoneal STS.29
The usual dose of preoperative RT is 50 Gy. In a single-institution study, Tzeng et al30 demonstrated that preoperative RT with selective dose escalation (45 Gy in 25 fractions to the entire tumor plus margin and a boost dose of 57.5 Gy to the posterior retroperitoneal tumor margin determined by the surgeon and the radiation oncologist to be at highest risk) was tolerable and allowed for the use of higher RT doses to the high-risk clinical target volume (CTV) judged to be at greatest risk for local tumor recurrence. In this study, which included 16 patients with biopsy-proven retroperitoneal STS, 14 patients (88%) had undergone macroscopic resection. With a median follow-up of 28 months, only 2 local recurrences were seen, with the actuarial 2-year local control rate of 80%. Because this approach is used in many NCCN Member Institutions, the guidelines have included this dosing schedule (45.0-50.0 Gy to the entire CTV with a dose-painted simultaneous integrated boost to a total dose of 57.5 Gy) as another option for preoperative RT (see SARC-D, 3 of 4, above). The panel recommends that higher-risk retroperitoneal tumor margins should be jointly defined by the surgeon and radiation oncologist.
Postoperative RT
Postoperative RT has been associated with improved RFS in retrospective nonrandomized studies, with no improvement in OS.31,32 In one study, the combined use of preoperative RT and postoperative brachytherapy resulted in significantly better DFS and OS in patients with low-grade tumors.33 In a recent retrospective study, the use of conformal postoperative RT along with aggressive surgical resection was associated with a trend toward decreased local recurrence rate and improved RFS compared with surgery alone.34 At the 5-year follow-up, the RFS rate was 60% and 47%, respectively (P=.02); however, there was no significant difference in OS between the groups. If postoperative RT is to be considered, a coordinated effort by the surgeon and radiation oncologist to displace the bowel from the tumor bed with omentum, or other tissue displacers, is recommended to reduce the risk of RT-related bowel toxicity.
NCCN Guidelines Insights: Soft Tissue Sarcoma, Version 2.2014
Version 2.2014 © National Comprehensive Cancer Network, Inc. 2014, All rights reserved. The NCCN Guidelines® and this illustration may not be reproduced in any form without the express written permission of NCCN®.
Citation: Journal of the National Comprehensive Cancer Network J Natl Compr Canc Netw 12, 4; 10.6004/jnccn.2014.0053
Intraoperative RT
The use of IORT has provided encouraging results in patients with retroperitoneal STS.35-41 In patients with retroperitoneal STS prospectively treated at a single institution with a protocol involving maximal tumor resection, high-dose-rate IORT, and postoperative external-beam RT, the overall 5-year local control rate for the whole group was 62%; local control rate was better for patients with primary tumors than for those with recurrent tumors (74% vs 54%; P=.4).36 The overall 5-year distant metastasis-free survival rate was 82% (100% for patients with low-grade tumors vs 70% for those with high-grade tumors; P=.05). The 5-year DFS and OS rates were 55% and 45%, respectively. IORT with or without external-beam RT has been effective in terms of local control and survival in patients with primary and recurrent retroperitoneal STS.37-39,41 In a study that assessed the long-term outcome of patients with retroperitoneal STS treated with preoperative RT, resection, and IORT with electron-beam RT (IOERT), patients undergoing gross total resection and IOERT had better OS (74% and 30%, respectively) NCCN guidelines local control (83% and 61%, respectively) rates compared with patients who underwent only gross total resection.37
NCCN Recommendations
The panel emphasizes that RT is not a substitute for definitive surgical resection with oncologically appropriate margins, and that re-resection may be necessary. If re-resection is not feasible, postoperative RT may be considered in highly selected patients in attempt to control microscopic residual disease in those who have not received preoperative RT, although this approach has not been validated in randomized trials.
Resectable Disease: Surgery (to obtain oncologically appropriate margins) with or without IORT is the primary treatment for most patients with resectable disease (see RETSARC-2, page 476).
Preoperative RT or chemotherapy could be considered before surgery in patients whose diagnosis has been confirmed through biopsy (see RETSARC-2, page 476). For patients treated with preoperative external-beam RT (50 Gy) followed by surgery, the guidelines recommend consideration of a postoperative RT boost for patients with positive margins, if this can be performed within the constraints of adjacent normal tissue. The guidelines recommend an external-beam RT boost of 16 to 18 Gy for microscopic residual disease, and 20 to 26 Gy for grossly positive margins (see SARC-D, 3 of 4, page 479). Alternatively, IORT (10.0-12.5 Gy for microscopic residual disease and 15 Gy for gross residual disease) can be delivered immediately after resection to the area at risk, avoiding the uninvolved organs (see SARC-D, 3 of 4, page 479).
Postoperative treatment options are dependent on surgical outcomes and clinical or pathologic findings after surgery. Postoperative RT should not be administered routinely, but could be considered for patients with microscopic positive margins (R1 resection) who have not received preoperative RT, and after negative margin resection (R0 resection) in highly selected patients (eg, those with pathologic findings of high-grade disease, extremely large tumors, close surgical margins, or high risk of recurrence) (see RETSARC-3, page 477). Re-resection, if feasible, should be considered for patients with macroscopic positive margins (R2 resection). Alternatively, these patients could also be managed as described later for unresectable disease. The options for postoperative RT include external-beam RT (50 Gy irrespective of surgical margins) or IORT (10 Gy followed by external-beam RT) (SARC-D, 4 of 4, page 480). For patients treated with postoperative external-beam RT, the NCCN guidelines recommend postoperative RT boost to the original tumor bed based on the margin status (10 Gy for negative surgical margin if normal tissue can be adequately spared by tissue displacement with omentum or other biologic or synthetic spacer; 16 to 18 Gy for microscopic residual disease and 20 to 26 Gy for gross residual disease). The dose recommendations mentioned earlier must be balanced and considered in the context of the adjacent normal tissue tolerance to RT.
Unresectable or Stage IV Disease: Unresectable tumors are defined as those that involve vital structures or whose removal would cause unacceptable morbidity. Patients who are medically unresectable (ie, not medically fit to tolerate a major retroperitoneal STS resection) are also included in this category.
Biopsy is recommended before any treatment for a patient with unresectable or metastatic disease. Patients with unresectable or stage IV disease could be treated with chemotherapy or RT in an attempt to downstage tumors (see RETSARC-4, page 478). For patients undergoing definitive high-dose RT, favorable experience has been reported with tissue displacement spacers to keep bowel out of the high-dose RT volume.42 Patients whose tumors become resectable after primary treatment should be managed as described earlier for resectable disease. If the tumor remains unresectable or if disease progression occurs after primary treatment, management decisions depend on whether patients are symptomatic or asymptomatic. Asymptomatic patients can be observed, whereas symptomatic patients can be treated with palliative therapy (chemotherapy, RT, or surgery) for symptom control or best supportive care. In patients with stage IV disease, resection should always be considered for resectable metastatic disease. Palliative RT involves expedient treatment with a dose sufficient to halt tumor growth or cause tumor regression. The outcome of this approach depends on the rapidity of growth and the status of systemic disease.
Recurrent Disease: For patients with resectable, unresectable, or disseminated recurrences, the NCCN Guidelines recommend the same management after biopsy as outlined for primary disease. Enrollment in a clinical trial is preferred and should be considered if an appropriate trial is available.
Summary
STS are a heterogeneous group of rare solid tumors with distinct clinical and pathologic features. Multimodality treatment (surgery with RT and/or chemotherapy) is often used for the management of patients with retroperitoneal/intra-abdominal STS. Most importantly, before initiation of treatment, all patients with STS should be evaluated and managed by a multidisciplinary team with extensive expertise and experience in the treatment of STS. Genetic testing and counseling should be recommended for patients with a clinical and/or family history of genetic cancer syndromes associated with a predisposition for the development of STS.
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