The management of soft tissue sarcomas

Trends in Overall Survival among Patients Treated for Sarcoma at a Large Tertiary Cancer Center between 1986 and 2014

Sarcomas are relatively rare malignancies accounting for about 1% of all cancer diagnoses. Studies on sarcomas comprising large cohorts covering extended time periods are lacking. Therefore, this study aimed to evaluate the impact of demographic, behavioral, and clinical characteristics on overall survival (OS) among individuals diagnosed with soft tissue sarcoma (STS) or bone sarcoma at the Moffitt Cancer Center between 1986 and 2014. Unadjusted and multivariable Cox proportional hazard regression (CPHR) models were constructed to generate hazard ratios (HRs) and 95% confidence intervals (CIs) to evaluate associations between a range of demographic, behavioral, and clinical characteristics, and OS. Additionally, Kaplan-Meier survival curves, associated log-rank statistics, and adjusted CPHR models were generated by time periods based on the year of first contact (1986-1994, 1995-1999, 2000-2005, 2006-2010, 2011-2014) to evaluate for temporal differences in OS. Of the 2570 patients, 2037 were diagnosed with STS, whereas 533 were diagnosed with bone sarcoma. At the time of analysis, 50% of the population were alive. In multivariable analyses, we observed poorer survival for patients ≥ 40 years of age (HR = 1.54, 95% CI = 1.34-1.78), current smokers (HR = 1.18, 95% CI = 1.01-1.37), patients with metastasis (HR = 2.19, 95% CI = 1.95-2.47), and patients not receiving first-line surgery treatment (HR = 2.11, 95% CI = 1.82-2.45). We discovered limited improvements in OS over time among individuals diagnosed with STS or bone sarcomas with the exception of gastrointestinal stromal tumors (GIST), which showed a significant improvement in OS across time periods (p = 0.0034). Overall, we identified well-established characteristics associated with OS (e.g., metastasis) in addition to factors (e.g., smoking status) not previously reported to impact OS. Improvements in survival over time have been relatively modest, suggesting the need for improved therapeutic options, especially for those diagnosed with less frequent sarcomas.

Nomogram Based on Ultrasonography and Clinical Features for Predicting Malignancy in Soft Tissue Tumors

Purpose

The objective of this study was to establish a predictive nomogram based on ultrasound (US) and clinical features for patients with soft tissue tumors (STTs).

Patients and Methods

A total of 260 patients with STTs were enrolled in this retrospective study and were divided into a training cohort (n=200, including 110 malignant and 90 benign masses) and a validation cohort (n=60, including 30 malignant and 30 benign masses). Multivariate analysis was performed by binary logistic regression analysis to determine the significant factors predictive of malignancy. A simple nomogram was established based on these independent risk factors including US and clinical features. The predictive accuracy and discriminative ability of the nomogram were measured by the calibration curve and the concordance index (C-index).

Results

The nomogram, comprising US features (maximum diameter, margin and vascular density) and clinical features (sex, age, and duration of disease), showed a favorable performance for predicting malignancy, with a sensitivity of 88.2% and a specificity of 78.7%. The calibration curve for malignancy probability in the training cohort showed good agreement between the nomogram predictions and actual observations. The C-indexes of the training cohort and validation cohort for predicting malignancy were 0.89 (95% CI: 0.85–0.94) and 0.83 (95% CI: 0.73–0.94), respectively.

Conclusion

The nomogram based on US and clinical features could be a simple, intuitive and reliable tool to individually predict malignancy in patients with STTs.

Relevance of Reference Centers in Sarcoma Care and Quality Item Evaluation: Results from the Prospective Registry of the Spanish Group for Research in Sarcoma (GEIS)

BACKGROUND

Reference centers (RCs) are a key point for improving the survival of patients with soft-tissue sarcomas (STS). The aim of this study was to evaluate selected items in the management of patients with STS, comparing results between RC and local hospitals (LHs).

MATERIALS AND METHODS

Diagnostic and therapeutic data from patients diagnosed between January 2004 and December 2011 were collected. Correlation with outcome was performed.

RESULTS

A total of 622 sarcomas were analyzed, with a median follow-up of 40 months. Imaging of primary tumor preoperatively (yes vs. no) correlated with a higher probability of free surgical margins (77.4% versus 53.7%; p = .006). The provenance of the biopsy (RC vs. LH) significantly affected relapse-free survival (RFS; 3-year RFS 66% vs. 46%, respectively; p = .019). Likewise, 3-year RFS was significantly worse in cases with infiltrated (55.6%) or unknown (43.4%) microscopic surgical margins compared with free margins (63.6%; p < .001). Patients managed by RCs had a better 3-year overall survival compared with those managed by LHs (82% vs. 70.4%, respectively; p = .003). Perioperative chemotherapy in high-risk STS, more frequently administered in RCs than in LHs, resulted in significantly better 3-year RFS (66% vs. 44%; p = .011). In addition, patients with stage IV disease treated in RCs survived significantly longer compared with those in LHs (30.4 months vs. 18.5 months; p = .036).

CONCLUSION

Our series indicate that selected quality-of-care items were accomplished better by RCs over LHs, all with significant prognostic value in patients with STS. Early referral to an RC should be mandatory if the aim is to improve the survival of patients with STS.

IMPLICATIONS FOR PRACTICE

This prospective study in patients diagnosed with soft-tissue sarcoma shows the prognostic impact of reference centers in the management of these patients. The magnitude of this impact encompasses all steps of the process, from the initial management (performing diagnostic biopsy) to the advanced disease setting. This is the first prospective evidence showing improvement in outcomes of patients with metastatic disease when they are managed in centers with expertise. This study provides extra data supporting referral of patients with sarcoma to reference centers.

Sister Chromatid Exchange and Genomic Instability in Soft Tissue Sarcomas: Potential Implications for Response to DNA-Damaging Treatments

Sarcomas are rare heterogeneous malignancies of mesenchymal origin characterised by complex karyotypes but no specific abnormalities. Recurrence is common, and metastatic disease carries poor survival despite standard DNA-damaging radiotherapy or chemotherapy. DNA double-strand breaks (DSBs) are either repaired by mechanisms such as homologous recombination (HR) or result in cell death by apoptosis. Endogenous γH2AX formation and SCE formation are early and late events, respectively, and their levels are considered surrogate measures of genomic instability. Combined γH2AX and SCE analysis was used to evaluate endogenous DNA DSB levels (and their subsequent repair) in 9 primary sarcoma cell lines and compared with well-established commercial lines. All the sarcoma cell lines had elevated γH2AX and SCE levels, but there was no correlation between the DNA DSB frequency and subsequent SCE. Typically, radioresistant osteosarcoma cells had relatively low γH2AX frequency but high SCE counts suggestive of efficient DNA repair. Conversely, liposarcoma cells derived from a radiosensitive tumour had high H2AX but relatively lower SCE levels that may imply inefficient DNA DSB repair. To our knowledge, this is the first report that correlates H2AX and SCE levels in primary sarcoma cell lines and may provide insight into potential response to DNA-damaging treatments.

Adherence to Guidelines for Adult (Non-GIST) Soft Tissue Sarcoma in the Netherlands: A Plea for Dedicated Sarcoma Centers

INTRODUCTION

Optimal management of soft tissue sarcoma (STS) remains a challenge. A nationwide survey assessed the quality of STS care in the Netherlands, thereby aiming to identify potentialities for improvement through more centralized disease management.

METHODS

From the Netherlands Cancer Registry (NCR), data were obtained on 3317 adult STS patients (excluding gastrointestinal stromal tumor, GIST) diagnosed in 2006-2011. Logistic regression models were employed to compare outcomes on selected clinical indicators reflecting prevailing STS guidelines between high-volume (≥10 resections annually) and low-volume (<10 resections) hospitals, between academic and general hospitals, and between sarcoma research centers and other hospitals, adjusted for case mix. Analyses were performed on imputed datasets (m = 50), generated through multiple imputations by chained equations.

RESULTS

Overall, 89% of patients underwent surgical resection. Resection status remained unknown in 24% (excluding those with metastasized disease), and grade was not documented for one-third of tumors. Microscopic residual disease was detected in 20% with an increased risk for older patients, larger and deeply located tumors, and those located in the (retro)peritoneum or upper extremity. Almost half of patients with an R1 resection received adjuvant radiotherapy. Following adjustment for case mix factors, patients treated in high-volume hospitals less often had macroscopic residual disease (R2 resection; adjusted odds ratio: 0.54). A strongly skewed distribution of surgical volumes was observed.

CONCLUSIONS

These survey results indicate a potential for improving Dutch STS care. More centralized sarcoma management should improve definitive pathology reporting on tumor characteristics, adherence to treatment guidelines and overall disease outcome.

Accuracy and role of contrast-enhanced CT in diagnosis and surgical planning in 88 soft tissue tumours of extremities

OBJECTIVES

Soft tissue tumours (STT) require accurate diagnosis in order to identify potential malignancies. Preoperative planning is fundamental to avoid inadequate treatments. The role of contrast-enhanced computed tomography (CT) for local staging remains incompletely assessed. Aims of the study were to evaluate CT accuracy in discriminating active from aggressive tumours compared to histology and evaluate the role of CT angiography (CTA) in surgical planning.

MATERIALS AND METHODS

This retrospective cohort series of 88 cases from 1200 patients (7 %) was locally studied by contrast-enhanced CT and CTA in a referral centre: 74 malignant tumours, 14 benign lesions. Contrast-enhancement patterns and relationship of the mass with major vessels and bone were compared with histology on surgically excised samples. Sensitivity, specificity, positive and negative predictive values (PPV, NPV) were evaluated in discriminating active from aggressive tumours.

RESULTS

Sensitivity in differentiating aggressive tumours from active lesions was 89 %, specificity 84 %, PPV 90 %, NPV 82 %. The relationship between mass and major vessels/bone was fundamental for surgical strategy respectively in 40 % and in 58 % of malignant tumours.

CONCLUSION

Contrast-enhanced CT and CTA are effective in differentiating aggressive masses from active lesions in soft tissue and in depicting the relationship between tumour and adjacent bones and major vessels.

KEY POINTS

• Accurate delineation of vascular and bony involvement preoperatively is fundamental for a correct resection. • CT plays a critical role in differential diagnosis of soft tissue masses. • Contrast-enhanced CT and CT angiography are helpful in depicting tumoral vascular involvement. • CT is optimal for characterization of bone involvement in soft tissue malignancies.

Diagnostic triage for sarcoma: an effective model for reducing referrals to the sarcoma multidisciplinary team

OBJECTIVE

Soft-tissue lesions are common and often benign. Owing to the rarity of soft-tissue sarcomas (STSs), evidence has shown that patients are increasingly referred urgently onto the 2-week wait pathway, which may have a detrimental impact on the management of patients with a proven STS. Imaging plays a vital role in lesion characterization and can be used to triage referrals to reduce the caseload of a sarcoma multidisciplinary team (MDT). In our institution, we established a sarcoma diagnostic triage meeting (SDTM). This study aimed to determine the effectiveness of the SDTM in reducing non-sarcomatous referrals to the main sarcoma MDT.

METHODS

A retrospective review of the SDTM minutes from July 2011 to June 2012 was performed. Data collected for each case included details of referrer, referral modality and referral outcome.

RESULTS

165 cases were reviewed. 58% of referrals underwent a core biopsy or surgical excision with 85% benign pathology, the commonest being lipoma. 15% of referrals were sarcomatous lesions and were referred onwards to the main MDT.

CONCLUSION

A total of 82% of the patients referred urgently with a suspicious soft-tissue mass was managed by the SDTM and hence not referred onwards to the East Midlands Sarcoma Service MDT. A diagnostic triage is effective in reducing the caseload burden of the main MDT and allowing it to be more effective.

ADVANCES IN KNOWLEDGE

Referrals based on imaging can be prioritized by diagnostic triage. Diagnostic triage established in our institution reduced 82% of MDT referrals allowing a more focused MDT discussion on patients with a proven sarcoma.

Saving grace: distally pedicled gracilis muscular flap in lower limb salvage

During the 1970s, the incidence of limb amputation following surgery for sarcoma excision was as high as 50%. Two important developments have led to modern day limb salvage, namely chemotherapy and precision imaging techniques. We present a case of limb salvage in a patient with osteosarcoma plagued with recurrent infection after prosthetic revision. We discuss the use of the distally based pedicled gracilis muscular flap, which has little mention as a reconstructive option for defects around the knee.

[Health care circuit for patients with soft tissue sarcomas of the extremities. A tortuous and slow road to referral units]

OBJECTIVE

To analyse the waiting periods elapsed since soft tissue sarcomas become symptomatic until their specific treatment in our unit, and to determine new strategies for the improvement of referral circuits.

MATERIAL AND METHODS

This is an ambispective observational study of a cohort of 61 patients, with previously untreated soft tissue sarcomas, obtained from our Musculoskeletal Tumors Database. Several variables related to the patient, tumour, and health care circuit were analysed, as well as the different periods between the initial symptoms of the disease and the first consultation in our unit. The significance level was α=0.05.

RESULTS

The mean size of the sarcomas was 11.3 cm. Thirty-six patients (59%) followed the usual circuit of the National Health System in Spain. The time elapsed since the disease became symptomatic until the first medical consultation was greater than 9.5 months, and nearly another 8.5 months to the consultation in our specific unit. Statistically significant relationships were found between the independent and dependent variables.

DISCUSSION

The study shows that the care of patients with soft tissue sarcomas in our environment is far away from the times of care in our neighbouring countries.

CONCLUSIONS

It is essential to make the population and health professionals aware of this disease, as well as to remember that there is a referral circuit that must be used.

Clinicians' adherence versus non adherence to practice guidelines in the management of patients with sarcoma: a cost-effectiveness assessment in two European regions

BACKGROUND

Although the management of sarcoma is improving, non adherence to clinical practice guidelines (CPGs) remains high, mainly because of the low incidence of the disease and the variety of histological subtypes. Since little is known about the health economics of sarcoma, we undertook a cost-effectiveness analysis (within the CONnective TIssue CAncer NETwork, CONTICANET) comparing costs and outcomes when clinicians adhered to CPGs and when they did not.

METHODS

Patients studied had a histological diagnosis of sarcoma, were older than 15 years, and had been treated in the Rhône-Alpes region of France (in 2005/2006) or in the Veneto region of Italy (in 2007). Data collected retrospectively for the three years after diagnosis were used to determine relapse free survival and health costs (adopting the hospital's perspective and a microcosting approach). All costs were expressed in euros (€) at their 2009 value. A 4% annual discount rate was applied to both costs and effects. The incremental cost-effectiveness ratio (ICER) was expressed as cost per relapse-free year gained when management was compliant with CPGs compared with when it was not. To capture uncertainty surrounding ICER, a probabilistic sensitivity analysis was performed based on a non-parametric bootstrap method.

RESULTS

A total of 219 patients were included in the study. Compliance with CPGs was observed for 118 patients (54%). Average total costs reached 23,571 euros when treatment was in accordance with CPGs and 27,313 euros when it was not. In relation to relapse-free survival, compliance with CPGs strictly dominates non compliance, i.e. it is both less costly and more effective. Taking uncertainty into account, the probability that compliance with CPGs still strictly dominates was 75%.

CONCLUSIONS

Our findings should encourage physicians to increase their compliance with CPGs and healthcare administrators to invest in the implementation of CPGs in the management of sarcoma.