Surgical treatment of pulmonary metastases from soft tissue sarcomas: a retrospective study in The Netherlands

Radiomics-based machine-learning method for prediction of distant metastasis from soft-tissue sarcomas

AIM

To construct and validate a radiomics-based machine-learning method for preoperative prediction of distant metastasis (DM) from soft-tissue sarcoma.

MATERIALS AND METHODS

Seventy-seven soft-tissue sarcomas were divided into a training set (n=54) and a validation set (n=23). The performance of three feature selection methods (ReliefF, least absolute shrinkage and selection operator [LASSO], and regularised discriminative feature selection for unsupervised learning [UDFS]) and four classifiers, random forest (RF), logistic regression (LOG), K nearest neighbour (KNN), and support vector machines (SVMs), were compared for predicting the likelihood of DM. To counter the imbalance in the frequencies of DM, each machine-learning method was trained first without subsampling, then with the synthetic minority oversampling technique (SMOTE). The performance of the radiomics model was assessed using area under the receiver-operating characteristic curve (AUC) and accuracy (ACC) values.

RESULTS

The performance of the LASSO and SVM algorithm combination used with SMOTE was superior to that of the algorithm combination alone. The combination of SMOTE with feature screening by LASSO and SVM classifiers had an AUC of 0.9020 and ACC of 91.30% in the validation dataset.

CONCLUSION

A machine-learning model based on radiomics was favourable for predicting the likelihood of DM from soft-tissue sarcoma. This will help decide treatment strategies.

Prognostic influence of the treatment approach for pulmonary metastasis in patients with soft tissue sarcoma

Soft tissue sarcomas (STSs) are rare heterogeneous malignancies of mesenchymal origin. Pulmonary metastases develop in approximately 50% of the patients with high-grade STS, being the major cause of mortality in patients with metastatic STS. Pulmonary metastasectomy has been reported to contribute to long-term survival; however, an appropriate treatment has not been established. We aimed to identify factors associated with post-metastasis survival in STS patients with pulmonary metastasis and determine the appropriate treatment for each patient. We retrospectively reviewed the records of metastatic STS patients treated between 2000 and 2017 and analyzed the clinico-pathologic variables to identify factors associated with the survival. The median survival after pulmonary metastasis was 20.6 months, and the 1-, 3-, and 5-year survival rates were 68.6%, 36.0%, and 25.1%, respectively. The survival was significantly greater in patients who underwent pulmonary metastasectomy than in those without surgery (38.9 months vs. 10.5 months; p < 0.0001). Among those who did not undergo surgery, the survival was significantly greater in patients who received chemotherapy than in those without chemotherapy (19.1 months vs. 6.3 months, p = 0.037). Multivariate analysis identified pulmonary metastasectomy as the most important prognostic factor for post-metastasis survival (Hazard ratio 5.623; 95% Confidence Interval 2.733-11.572; p < 0.0001). In conclusion, pulmonary metastasectomy was the most important prognostic factor for post-metastasis survival in patients with metastatic STS. In addition, chemotherapy could prolong survival in patients who were not eligible for pulmonary resection. Although we should carefully weigh the risks and benefits, appropriate treatment for pulmonary metastases could contribute to long-time survival.

Post-metastasis survival in extremity soft tissue sarcoma: a recursive partitioning analysis of prognostic factors

BACKGROUND

Recursive partitioning analysis (RPA) enables grouping of patients into homogeneous prognostic groups in a visually intuitive form and has the capacity to account for complex interactions among prognostic variables. In this study, we employed RPA to generate a prognostic model for extremity soft tissue sarcoma (STS) patients with metastatic disease.

METHODS

A retrospective review was conducted on 135 patients with metastatic STS who had undergone surgical removal of their primary tumours. Patient and tumour variables along with the performance of metastasectomy were analysed for possible prognostic effect on post-metastatic survival. Significant prognostic factors on multivariate analysis were incorporated into RPA to build regression trees for the prediction of post-metastatic survival.

RESULTS

RPA identified six terminal nodes based on histological grade, performance of metastasectomy and disease-free interval (DFI). Based on the median survival time of the terminal nodes, four prognostic groups with significantly different post-metastatic survival were generated: (1) group A: low grade/metastasectomy; (2) group B: low grade/no metastasectomy/DFI ⩾ 12 months or high grade/metastasectomy; (3) group C: low grade/no metastasectomy/DFI < 12 months or high grade/no metastasectomy/DFI ⩾ 12 months; and (4) group D: high grade/no metastasectomy/DFI < 12 months. The 3-year survival rates for each group were: group A, 76.1 ± 9.6%; group B, 42.3 ± 10.3%; group C, 18.8 ± 8.0%; and group D, 0.0 ± 0.0%.

CONCLUSION

Our prognostic model using RPA successfully divides STS patients with metastasis into groups that can be easily implemented using standard clinical parameters.

Effective utilization of chest X-ray for follow-up of metastatic lung tumor due to soft tissue sarcoma

Computed tomography (CT) is widely used for follow-up of lung metastasis in patients due to soft tissue sarcoma (STS), the frequency of chest X-ray (CXR) is obviously reduced. This study verified the current status of diagnostic measures and the efficacy of CXR. A retrospective analysis of 18 patients that underwent surgery for lung metastasis due to STS was performed. The investigation compared the follow-up interval using CT after STS surgery, time from STS surgery to lung metastasis, tumor size of lung metastasis, detection rate with CXR, time from detection to surgery for lung metastasis, number of CT scans and follow-up interval using CT after detection of lung metastasis. The follow-up interval when using CT after STS surgery was 3.5 months (m). Time from STS surgery to lung metastasis was 34.3m. Tumor size of lung metastasis was 15 mm, and the detection rate by CXR was 66.7%. The time from detection to surgery for lung metastasis was 4.8m, the number of CT scans was 3.1, and the interval was markedly shortened to 1.6m. Follow-up should be performed by CXR if the tumor is detected by CXR. CT evaluation is required when the tumor size has increased, and prior to surgery for lung metastasis.

Adult pelvic sarcomas: a heterogeneous collection of sarcomas?

Introduction. Adult pelvic soft tissue sarcomas are a rare group of heterogeneous malignancies. These sarcomas differ from extremity and trunk soft tissue sarcomas in presentation, characteristics and response to treatment.

Methods. A retrospective analysis of patient and tumor characteristics, treatment and prognosis and prognostic factors was performed.

Results. Between 1977 and 1997, a total of 33 adult patients with soft tissue sarcomas involving the pelvis but excluding uterine leiomyosarcoma were identified. Leiomyosarcomas (18), including six GIST, and rhabdomyosarcomas (eight) were the most commonly seen tumors. At first presentation, nine patients already had metastases. The mean follow-up was 52 months (1–200). Recurrences developed in 15 of the 24 cases (63%) with tumors without metastases at first presentation; in six (25%) recurrence was locally only, in nine distant metastases occurred. The nine patients with metastatic disease at first presentation died of the disease, while eight of the 24 patients with localized disease at presentation died. One patient died of an unrelated cause, four were alive with disease, and 11 patients were alive and free of disease. The only identifiable prognostic factor of disease-free interval and overall survival was histological grade.

Conclusion. Soft tissue sarcomas of the pelvis appear to be associated with increased rate of metastasis at the time of diagnosis and higher rates of local recurrence. In this study, multi-modality treatment for most primary tumors did not show a significant benefit in recurrence rate, DFI and OST, when compared to single modality approach. Although the number of patients in this study is small, and different types of sarcomas were studied, the only identifiable predictor for survival was low histological grade of the tumors. The differences of this heterogeneous group of pelvic sarcomas with retroperitoneal, trunk and extremity sarcomas should be taken into consideration in the management of these sarcomas.

Current status of pulmonary metastasectomy

Malignant disease's ability to metastasize remains one of the major obstacles when treating patients with cancer. The change from loco-regional to systemic disease usually renders the patient beyond surgical treatment, as local treatment with surgery in a systemic disease is usually considered without benefit. However, numerous retrospective studies have demonstrated that resection of metastases limited to the lungs may be associated with prolonged survival. No prospective, randomized studies have been published, and most series compare highly selected patients with historical data for unresected patients. In this article, we discuss the current status on pulmonary metastasectomy. Preoperative assessment and selection of surgical candidates is covered. The different surgical strategies including surgical approach, unilateral versus bilateral exploration, lymph node dissection, and repeat surgery are discussed. Finally, we review some of the common tumors that metastasize to the lungs, the role of metastasectomy in their treatment and the prognostic factors with impact on survival.

The role of surgery in the management of isolated metastases to the pancreas

Metastasectomy with curative intent has become standard practice for the management of some malignancies. Resection of isolated metastatic colorectal cancer, gastrointestinal stromal tumours, neuroendocrine cancers, renal-cell cancer and sarcoma is associated with longer survival or even cure. The strongest evidence in favour of metastasectomy exists for colorectal cancer, in which resection of limited metastatic disease in some patients is associated with 5-year survival rates of more than 50%.(1-3) High incidence of the disease, predictable tumour biology, and development of successful chemotherapies have encouraged metastasectomy. Furthermore, improved safety of complex surgeries over the past several decades has lowered the threshold for more aggressive surgical intervention. Most literature on metastasectomy pertains to the resection of disease involving the liver, lung, and brain. However, metastasectomy has been described for almost every organ system, including the pancreas. In this Review, we discuss resection of isolated cancer metastases to the pancreas. Pancreatic metastasectomy is most often done through a formal pancreatic resection such as pancreaticoduodenectomy or distal pancreatectomy. Less often, pancreatic metastasectomy is done by enucleation or a pancreas sparing operation such as a central pancreatectomy.

Multidisciplinary management of metastatic sarcoma

Soft tissue sarcomas comprise a heterogeneous group of malignancies of mesenchymal origin. Although sarcomas can arise virtually anywhere, the most common primary site is the extremity. The development of metastatic disease poses a major clinical problem because it is seldom amenable to a curative treatment. However, with careful and expert multidisciplinary team selection of patients with metastatic sarcoma-balancing probability of benefit with certain toxicity-a combined multimodality approach may provide hope to a select few for prolonged survival and even cure.

Lymphadenectomy for isolated lymph node metastasis from extremity soft-tissue sarcomas

BACKGROUND

Previous studies have suggested that the prognosis in patients with extremity soft-tissue sarcomas (ESTS) with isolated lymph node (LN) metastases (stage IV) is comparable to that of patients with high-risk ESTS without metastases (stage III). This study was performed to determine the outcomes of patients who underwent aggressive therapy, including lymphadenectomy in patients with LN metastasis from ESTS.

METHODS

Demographic details, pathology of the primary disease, timing of LN metastasis, and details of the multimodality treatment were obtained from the medical records of 35 patients with nodal metastasis from ESTS who were treated between 1981 and 2003. Survival after the diagnosis of primary disease and LN metastasis was compared with established historical outcomes for patients with American Joint Commission on Cancer (AJCC) stages III and IV ESTS.

RESULTS

Epithelioid sarcomas (23%) and malignant fibrous histiocytomas (23%) were the most common primary histologic types. Twenty (57%) patients presented with synchronous nodal metastasis. Median follow-up from the time of diagnosis of lymph node metastasis was 48.5 months. The 1-year, 2-year, and 5-year actuarial survival rates in patients with synchronous nodal metastasis after lymphadenectomy and additional therapy were 79%, 62%, and 52%, respectively. In comparison, the 1-year, 2-year, and 5-year actuarial survival rates in patients with metachronous nodal metastasis after lymphadenectomy and additional therapy were 100%, 95%, and 66%, respectively.

CONCLUSIONS

Patients with isolated regional lymph node metastases who are treated with aggressive approaches, including regional LN dissection, may experience prolonged survival similar to that which more closely approximates the survival seen in patients with stage III disease (5-year survival rate, 50%) rather than the survival seen in patients with stage IV disease (5-year survival rate, 25%). These data lend support for reconsideration of the current AJCC staging system for ESTS.

Soft tissue sarcoma: why not treated?

BACKGROUND

Soft tissue sarcomas (STS) are uncommon malignancies and elderly STS patients have been reported to receive less definitive treatment compared to young STS patients. The present study was performed to investigate whether withholding treatment was based on disease specific aspects, patients' general health condition, comorbidity or a combination of these.

METHODS

Patients with primary STS, registered by the Comprehensive Cancer Center North-Netherlands (CCCN) from 1989 to 1999, were analyzed retrospectively with regard to the inclusion-criteria: no primary anti-tumor treatment.

RESULTS

From 1989 to 1999, 620 patients (including 56 Kaposi sarcoma) were registered with primary STS. Seventy-six patients (13%) were registered as untreated. Nineteen patients were excluded. Records of 57 patients, median age 71 years (range 23-92, 40 patients > or =65 years, 17 patients < 65 years) were examined. The reasons for no treatment were irresectability of the sarcoma (65%), metastatic disease (11%), comorbidity (4%), poor general health (5%), death prior to therapy (7%) and refusal of therapy (3%) (motivation not documented in 5%).

CONCLUSIONS

Thirteen percent of all STS patients within the CCCN region were not treated, 70% of these patients were elderly. Withholding treatment was mostly disease-related (76%), e.g. irresectable retroperitoneal STS or metastatic disease; for 19% of the patients, it was related to their poor general health. The decision to refrain from cancer treatment was justifiable in all these STS patients.

Soft-tissue sarcomas

Sarcomas of the soft tissues are challenging lesions for the surgical oncologist. Careful planning must be done at all stages of diagnosis and treatment, because every sarcoma is unique with respect to histologic type, size, and location. Pretreatment discussions in a multidisciplinary format are useful to ensure appropriate and effective management of these tumors.

Pulmonary metastases from soft tissue sarcoma: analysis of patterns of diseases and postmetastasis survival

OBJECTIVE

To report the patterns of disease and postmetastasis survival for patients with pulmonary metastases from soft tissue sarcoma in a large group of patients treated at a single institution. Clinical factors that influence postmetastasis survival are analyzed.

SUMMARY BACKGROUND DATA

For patients with soft tissue sarcoma, the lungs are the most common site of metastatic disease. Although pulmonary metastases most commonly arise from primary tumors in the extremities, they may arise from almost any primary site or histology. To date, resection of disease has been the only effective therapy for metastatic sarcoma.

METHODS

From July 1982 to February 1997, 3149 adult patients with soft tissue sarcoma were admitted and treated at Memorial Sloan-Kettering Cancer Center. During this interval, 719 patients either developed or presented with lung metastases. Patients were treated with resection of metastatic disease whenever possible. Disease-specific survival was the endpoint of the study. Time to death was modeled using the method of Kaplan and Meier. The association of factors to time-to-event endpoints was analyzed using the log-rank test for univariate analysis and the Cox proportional hazards model for multivariate analysis.

RESULTS

The overall median survival from diagnosis of pulmonary metastasis for all patients was 15 months. The 3-year actuarial survival rate was 25%. The ability to resect all metastatic disease completely was the most important prognostic factor for survival. Patients treated with complete resection had a median survival of 33 months and a 3-year actuarial survival rate of 46%. For patients treated with nonoperative therapy, the median survival was 11 months. A disease-free interval of more than 12 months before the development of metastases was also a favorable prognostic factor. Unfavorable factors included the histologic variants of liposarcoma and malignant peripheral nerve tumors and patient age older than 50 years at the time of treatment of metastasis.

CONCLUSIONS

Resection of metastatic disease is the single most important factor that determines outcome in these patients. Long-term survival is possible in selected patients, particularly when recurrent pulmonary disease is resected. Surgical excision should remain the treatment of choice for metastases of soft tissue sarcoma to the lung.

Prognostic factors for the outcome of chemotherapy in advanced soft tissue sarcoma: an analysis of 2,185 patients treated with anthracycline-containing first-line regimens--a European Organization for Research and Treatment of Cancer Soft Tissue and Bone Sarcoma Group Study

PURPOSE

A total of 2,185 patients with advanced soft tissue sarcomas who had been treated in seven clinical trials investigating the use of doxorubicin- or epirubicin-containing regimens as first-line chemotherapy were studied in this prognostic-factor analysis.

PATIENTS AND METHODS

Overall survival time (median, 51 weeks) and response to chemotherapy (26% complete response or partial response) were the two end points. The cofactors were sex; age; performance status; prior therapies; the presence of locoregional or recurrent disease; lung, liver, and bone metastases at the time of entry onto the trial; long time period between the initial diagnosis of sarcoma and entry onto the study; and histologic type and grade.

RESULTS

Univariate analyses showed (a) a significant, favorable influence of good performance status, young age, and absence of liver metastases on both survival time and response rate, (b) a significant, favorable influence of low histopathologic disease grade on survival time, despite a significantly lower response rate, (c) increased survival time for patients with a long time period between the initial diagnosis of sarcoma and entry onto the study, despite equivalent response rates, and (d) increased survival time with liposarcoma or synovial sarcoma, a decreased survival time with malignant fibrous histiocytoma, a lower response rate with leiomyosarcoma, and a higher response rate with liposarcoma (P < .05 for all log-rank and chi2 tests). The Cox model selected good performance status (P < .0001), absence of liver metastases (P = .0001), low histopathologic grade (P = .0002), long time lapse since initial diagnosis (P = .0004), and young age (P = .0045) as favorable prognostic factors of survival time. The logistic model selected absence of liver metastases (P < .0001), young age (P = .0024), high histopathologic grade (P = .0051), and liposarcoma (P = .0065) as favorable prognostic factors of response rate.

CONCLUSION

This analysis demonstrates that for advanced soft tissue sarcoma, response to chemotherapy is not predicted by the same factors as is overall survival time. This needs to be taken into account in the interpretation of trials assessing the value of new agents for this disease on the basis of response to treatment.

Survival after pulmonary metastasectomy in soft tissue sarcoma. Prognostic factors in 214 patients

This retrospective study examines prognostic factors for post-metastasectomy survival in soft tissue sarcoma patients. Between 1976 and 1992, 274 consecutive patients (median age 49 [7-96] years) with pulmonary metastatic soft tissue sarcoma of the extremity or trunk wall (31 at presentation) were managed at the Mayo Clinic. 214 underwent pulmonary metastasectomy and 163 of these also received adjuvant chemotherapy. There were 195 local excisions, 14 lobectomies, and 5 pneumonectomies. 90 patients had solitary metastases, 184 patients had 2 or more metastases. 31% of patients had MFH tumors and 88% of all tumors were high grade. Median follow-up for survivors was 8 (2-21) years. 5-year overall survival after metastasectomy was approximately 40% (cf. 20% for non-metastasectomy). Age > 50, MFH tumors, > or = 2 metastases, metastasis size > 2 cm, metastasis-free period < or = 18 months, and the use of adjuvant chemotherapy were univariately unfavorable factors. Size of metastasis > 2 cm, number of metastases > or = 2, and metastasis-free interval < or = 18 months were independently unfavorable for survival. In a prognostic system, patients with 0 risk factors had a 60% 5-year survival, those with 1, 2, or 3 of these factors had 30%, 20% and 0% survival, respectively.

Metastasectomy for sarcomatous pediatric histologies: results and prognostic factors

We reviewed our experience of pediatric metastasectomy to define (1) morbidity/mortality in this population and (2) any preoperative or intraoperative prognostic predictors of survival. One hundred fifty-two patients with median age 19 years (range, 5 to 33 years) had 258 thoracic explorations (Ewing's sarcoma, 28; rhabdomyosarcoma, 6; nonrhabdomyosarcoma soft tissue sarcoma, 42; and osteosarcoma, 76). Resections were accomplished by 218 wedge resections, 19 anatomic resections, 14 wedge and anatomic resections, 4 wedge and chest wall resections, and 3 wedge resections/other procedures. An initial complete resection was accomplished in 121/152 patients (80%). With a median potential follow-up of 10.6 years, median survival from initial thoracotomy is 2.2 years. By the Cox proportional hazards model, three or more positive nodules (p = 0.021), histology other than osteosarcoma (p = 0.0054), and incomplete resection (p < 0.0001) were unfavorable prognostic factors for survival. Two or more positive nodules (p = 0.0049), left location (p = 0.0031), age 14 years or greater at diagnosis (p = 0.0052), or rhabdomyosarcoma (p = 0.0066) predicted shorter pulmonary progression-free survivals after resection. Nonrhabdomyosarcoma pediatric metastasectomy can yield selected long-term survival. Morbidity/mortality is low, and a complete resection, if possible, is paramount. Prognostic factors can be defined that can be used to define the limits of this therapy to the patient and family.

Pulmonary metastasectomy for soft tissue sarcomas: is it justified?

The role of pulmonary metastasectomy for metastatic soft tissue sarcomas is examined by reviewing the recent (1978-1994) English language literature. There are no prospective studies that contain an appropriate control group, and only one retrospective study contains a matched control group. In those few studies that provide greater than 5-year survival data, the survival curve still has a steep slope and few patients are alive at 7 years. In most studies only one or two patients are at risk at 5 years or more. Projected survival is therefore statistically questionable. It is currently impossible to know what is the impact of the surgical procedure over and above the natural history (biology) of the tumor. A randomized, prospective study, as suggested a decade ago, is still needed. While there may be some merit to pulmonary metastasectomy in highly selected patients, aggressive pulmonary metastasectomy does not seem justified by the available data.