Analysis of lung metastases in patients with primary extremity sarcoma

Improving survival after pulmonary metastasectomy for sarcoma: analysis of prognostic factors

BACKGROUND

Metastatic sarcoma confers a grave prognosis to patients and poses a management dilemma for clinicians. Pulmonary metastasectomy is frequently performed for the recurrence of sarcomatous tumours in the lung, but the evidence-base is poor. No guidelines exist to inform clinicians on appropriate patient selection and surgical technique.

AIM

This review aims to establish and analyse the most important prognostic factors for survival post pulmonary metastasectomy for recurrent sarcoma. We summarise the key tumour, peri-operative and patient characteristics that should guide surgical management.

METHODS

A comprehensive search of the literature utilising OVID Medline and PubMed databases was conducted to identify all relevant research within the past 15 years. We evaluated all articles that specifically studied sarcoma patients (both bone and soft tissue).

CONCLUSION

Disease-free interval and tumour burden remain important prognostic factors, while tumour grade is likely not significant. VATS is a safe and viable alternative to thoracotomy without sacrificing survival outcomes. No single peri-operative characteristic provides useful prognostic information in isolation.

Willingness of patients with sarcoma to participate in cancer surveillance research: a cross-sectional patient survey

OBJECTIVES

To determine the proportion of patients with extremity sarcoma who would be willing to participate in a clinical trial in which they would be randomised to one of four different postoperative sarcoma surveillance regimens. Additionally, we assessed patients' perspectives on the burden of cancer care, factors that influence comfort with randomisation and the importance of cancer research.

DESIGN

Prospective, cross-sectional patient survey.

SETTING

Outpatient sarcoma clinics in Canada, the USA and Spain between May 2017 and April 2020. Survey data were entered into a study-specific database.

PARTICIPANTS

Patients with extremity sarcoma who had completed definitive treatment from seven clinics across Canada, the USA and Spain.

MAIN OUTCOME MEASURES

The proportion of patients with extremity sarcoma who would be willing to participate in a randomised controlled trial (RCT) that evaluates varying postoperative cancer surveillance regimens.

RESULTS

One hundred thirty complete surveys were obtained. Respondents reported a wide range of burdens related to clinical care and surveillance. The majority of patients (85.5%) responded that they would agree to participate in a cancer surveillance RCT if eligible. The most common reason to participate was that they wanted to help future patients. Those that would decline to participate most commonly reported that participating in research would be too much of a burden for them at a time when they are already feeling overwhelmed. However, most patients agreed that cancer research will help doctors better understand and treat cancer.

CONCLUSIONS

These results demonstrate that most participants would be willing to participate in an RCT that evaluates varying postoperative cancer surveillance regimens. Participants' motivation for trial participation included altruistic reasons to help future patients and deterrents to trial participation included the overwhelming burden of a cancer diagnosis. These results will help inform the development of patient-centred RCT protocols in sarcoma surveillance research.

LEVEL OF EVIDENCE

V.

The Surveillance After Extremity Tumor Surgery (SAFETY) trial: protocol for a pilot study to determine the feasibility of a multi-centre randomised controlled trial

INTRODUCTION

Following the treatment of patients with soft tissue sarcomas (STS) that are not metastatic at presentation, the high risk for local and systemic disease recurrence necessitates post-treatment surveillance. Systemic recurrence is most often detected in the lungs. The most appropriate surveillance frequency and modality remain unknown and, as such, clinical practice is highly varied. We plan to assess the feasibility of conducting a multi-centre randomised controlled trial (RCT) that will evaluate the effect on overall 5-year survival of two different surveillance frequencies and imaging modalities in patients with STS who undergo surgical excision with curative intent.

METHODS AND ANALYSIS

The Surveillance After Extremity Tumor Surgery trial will be a multi-centre 2×2 factorial RCT. Patients with non-metastatic primary Grade II or III STS treated with excision will be allocated to one of four treatment arms1: chest radiograph (CXR) every 3 months for 2 years2; CXR every 6 months for 2 years3; chest CT every 3 months for 2 years or4 chest CT every 6 months for 2 years. The primary outcome of the pilot study is the feasibility of a definitive RCT based on a combination of feasibility endpoints. Secondary outcomes for the pilot study include the primary outcome of the definitive trial (overall survival), patient-reported outcomes on anxiety, satisfaction and quality of life, local recurrence-free survival, metastasis-free survival, treatment-related complications and net healthcare costs related to surveillance.

ETHICS AND DISSEMINATION

This trial received provisional ethics approval from the McMaster/Hamilton Health Sciences Research Ethics Board on 7 August 2019 (Project number 7562). Final ethics approval will be obtained prior to commencing patient recruitment. Once feasibility has been established and the definitive protocol is finalised, the study will transition to the definitive study.

TRIAL REGISTRATION

NCT03944798; Pre-results.

What Is the Clinical Importance of Incidental Findings on Staging CT Scans in Patients With Sarcoma?

BACKGROUND

Baseline staging CT scans are performed on nearly every patient after the diagnosis of a sarcoma to evaluate for the presence of metastatic disease. These scans often identify abnormalities that may or may not be related to the known malignancy. Despite the high frequency of incidental findings, there is little guidance for clinicians faced with assessing these radiographic abnormalities. The interpretation of incidental findings is important because it may influence decisions regarding surveillance frequency, prognostic estimation, and surgical and medical intervention.

QUESTIONS/PURPOSES

The purpose of this study was to determine (1) the frequency of abnormal findings and indeterminate nodules on staging CT scans; (2) the natural history of indeterminate nodules identified at the time of sarcoma diagnosis; and (3) the factors associated with indeterminate nodules representing true metastatic disease.

METHODS

Between September 2010 and February 2016 we treated 233 patients with bone and soft tissue sarcomas. Of those, 227 (97%) had a staging CT scan of the chest or chest/abdomen/pelvis performed within 2 months of diagnosis. To be eligible for this retrospective study, a patient had to have a minimum of 6 months of radiographic followup after that initial CT scan. A total of 36 (16%) were lost to followup or did not have radiographic surveillance at least 6 months later, and 48 (21%) were excluded for other prespecified reasons, leaving 149 patients for evaluation. We recorded all abnormal findings listed in the official radiology CT report of the lung, bone, liver, and lymph nodes. We assessed progression of indeterminate nodules by reviewing radiology reports, which listed both size and number of findings, and clinical notes outlining the current assessment of disease status and treatment plan. If indeterminate nodules grew in size or number consistent with metastatic disease or were confirmed histologically, they were considered to represent true metastasis. Bivariate methods were used to investigate an association between various clinical factors, which were obtained from chart review, and progression of indeterminate nodules to clear metastatic disease.

RESULTS

One hundred thirty-five of 149 patients (91%) had at least one abnormal finding on a staging CT scan. Forty-nine patients (33%) presented with indeterminate lung nodules, 15 (10%) with indeterminate liver lesions, four (3%) with indeterminate bone lesions, and 57 (38%) with enlarged lymph nodes. Fifteen of the 49 patients with indeterminate lung nodules (31%), one of 15 liver nodules, zero of four bone lesions, four of 13 lymph nodes 1 to 2 cm in size, and two of 44 subcentimeter lymph nodes (4.5%) were clearly metastatic on followup. A primary tumor size ≥ 14 cm in greatest dimension was more suggestive of indeterminate nodules representing true metastatic disease compared with smaller primary tumors in both lung (eight of 10 compared with seven of 36 [19%]; odds ratio, 16.6; 95% confidence interval, 2.9-95.9; p < 0.001) and lymph nodes (six of 18 compared with zero of 36 [0%], p < 0.001).

CONCLUSIONS

It is extremely common for abnormal findings and incidental nodules to be present at the time of a staging CT scan in patients with sarcoma. Although patients with indeterminate nodules should have continued surveillance, it appears from this study that the majority of these findings do not represent true metastatic disease. Given a minimum followup of 6 months, it is possible the actual proportion of indeterminate lesions representing true metastatic disease may increase over time.

LEVEL OF EVIDENCE

Level III, prognostic study.

Bilateral pneumothorax after general anesthesia in patient with pleomorphic sarcoma of soft tissue

The occurrence of a pneumothorax using supraglottic device is a rare complication during general anesthesia. Moreover, less than 2% of pneumothoraxes can be related to lung metastases, most due to soft tissue sarcoma. We present the case of a 45-year-old female diagnosed with metastatic sarcoma who developed a bilateral pneumothorax after general anesthesia with supraglottic device. Different causes of pneumothorax were discussed.

Spontaneous bilateral pneumothorax in a patient with metastatic synovial sarcoma while under chemotherapy

We report a case of synovial sarcoma of the lower limbs with pulmonary metastasis in a 24-year-old male patient who developed progressive spontaneous bilateral pneumothorax while he was on chemotherapy. Chest tubes inserted and achieved recovery in the left side whereas the right side became worse. Right lung decortication was carried out and the biopsy confirmed the diagnosis of synovial sarcoma metastasis. Thereafter, the patient was kept on chemotherapy of IV ifosfamide + etoposide D1-5, and after 2 cycles he traveled back to his country to continue treatment there.

The influence of pulmonary metastasectomy on survival in osteosarcoma and soft-tissue sarcomas: a retrospective analysis of survival outcomes, hospitalizations and requirements of home oxygen therapy

OBJECTIVES

Pulmonary metastasectomy for sarcoma is a widely accepted practice. Nevertheless, no previous studies has been reported the outcomes following metastasectomy compared with chemotherapy for patients with resectable and isolated pulmonary metastases. Our aim is to compare these modalities for the subset of patients with resectable metastases. Furthermore, the outcomes for patients with unresectable lung metastases are reported.

METHODS

Sarcoma patients with isolated lung metastases were identified and their computed axial tomography scans were reviewed by a thoracic surgeons' committee. Patients were divided into three groups: A: patients with resectable metastases treated with metastasectomy (n=29), B: patients with resectable metastases who received systemic therapy (n=17) and C: patients with unresectable metastases (n=25). Survival outcomes were plotted and compared through log-rank test for osteosarcoma and non-osteosarcoma patients.

RESULTS

Seventy-one patients (32 with osteosarcoma and 39 with non-osteosarcoma) were eligible. Progression-free survival (PFS) was superior in patients who belonged to Group A compared with Groups B and C (8.0, 4.3 and 2.2 months, respectively, P=0.0002). Furthermore, overall survival (OS) was superior in patients who belonged to Group A compared with Groups B and C (39.6, 20.0 and 7.8 months, respectively, P<0.0001). A subanalysis for osteosarcoma patients showed superior PFS and OS for Group A vs B (median PFS 21.6 and 3.65 months, respectively, P=0.011 and median OS 34.0 and 12.4 months, respectively, P=0.0044). For non-osteosarcoma patients, there were no such significant survival differences between Groups A and B. Overall, patients who belonged to Group A had significantly lower mean percentage of their follow-up time spent admitted at hospital, and a trend towards lower requirements for home oxygen therapy.

CONCLUSIONS

Pulmonary metastasectomy is associated with improved survival of osteosarcoma patients with resectable lung metastases. For non-osteosarcoma patients, the survival benefit of metastasectomy over chemotherapy is uncertain and warrants further evaluation. Patients with unresectable metastases have poor prognosis.

CT scans for pulmonary surveillance may be overused in lower-grade sarcoma

Chest CT scans are often used to monitor patients after excision of a sarcoma. Although sensitive, CT scans are more expensive than chest radiographs and are associated with possible health risks from a higher radiation dose. We hypothesized that a program based upon limited CT scans in lower-grade sarcoma could be efficacious and less expensive. We retrospectively assigned patients to a high-risk or low-risk hypothetical protocol. Eighty-three low- or intermediate-grade soft tissue sarcomas met our inclusion criteria. Eight patients had pulmonary metastasis. A protocol based on selective CT scans for high-risk patients would have identified seven out of eight lesions. The incremental cost-effectiveness ratio for routine CT scans was $731,400. A program based upon selective CT scans for higher-risk patients is accurate, spares unnecessary radiation to many patients, and is less expensive.

Computed tomographic criteria for the discrimination of subcentimeter lung nodules in patients with soft-tissue sarcomas

The aim of this study was to identify criteria for nodule characterization on chest computed tomography in patients with soft tissue sarcomas. In 195 patients, a total of 194 benign and 117 malignant subcentimeter lung nodules were retrospectively analyzed according to lesion size, shape, margins, density, and localization. Benign lesions more frequently displayed complex shape and were of ground-glass density (P<.0001, respectively). In contrast, round shape and solid density were more frequently found in malignant lesions (P<.0001, respectively).

The transcription factor EGR1 regulates metastatic potential of v-src transformed sarcoma cells

Metastatic spreading of cancer cells is a highly complex process directed primarily by the interplay between tumor microenvironment, cell surface receptors, and actin cytoskeleton dynamics. To advance our understanding of metastatic cancer dissemination, we have developed a model system that is based on two v-src transformed chicken sarcoma cell lines-the highly metastatic parental PR9692 and a non-metastasizing but fully tumorigenic clonal derivative PR9692-E9. Oligonucleotide microarray analysis of both cell lines revealed that the gene encoding the transcription factor EGR1 was downregulated in the non-metastatic PR9692-E9 cells. Further investigation demonstrated that the introduction of exogenous EGR1 into PR9692-E9 cells restored their metastatic potential to a level indistinguishable from parental PR9692 cells. Microarray analysis of EGR1 reconstituted cells revealed the activation of genes that are crucial for actin cytoskeleton contractility (MYL9), filopodia formation (MYO10), the production of specific extracellular matrix components (HAS2, COL6A1-3) and other essential pro-metastatic abilities.

Strain-specific susceptibility for pulmonary metastasis of sarcoma 180 cells in inbred mice

Most cancer deaths are a result of metastasis. To extend our understanding of the factors that influence the process, we aimed to develop a mouse model of pulmonary metastasis that can be assayed in multiple inbred mouse strains for further use in identification of host genetic variants that influence metastasis. We used i.v. injection of Sarcoma 180 (S180) cells, which can be tracked and quantified by bioluminescence imaging. We observed growth of S180 cells solely in the lung and observed a wide range of pulmonary metastasis among inbred mouse strains. Interestingly, we noted that the BTBRT+tf/J strain exhibited complete clearance and provide evidence that the mechanism of resistance may involve immune factors, as strains subjected to whole-body irradiation are significantly more susceptible to tumor growth. One possible mechanism of resistance to pulmonary metastasis in BTBRT+tf/J mice may require T-cell function. Our experiments present a new mouse model for further characterization of the genetics and mechanisms of pulmonary metastasis.