Patterns of Metastatic Recurrence of Genetically Confirmed Myxoid Liposarcoma

BACKGROUND

Most sarcomas metastasize predominantly to the lungs, and chest x-ray, or computed tomography, is the most commonly used staging investigation. Myxoid liposarcomas (MLSs) are rare tumors with a tendency to metastasize to extrapulmonary loci. The aim of this study was to assess the locations of the first metastases in MLS patients, to guide the design of effective staging and follow-up imaging protocols.

METHODS

Patients treated for MLS between 1987 and 2017 were identified in a prospectively maintained register. Histology of the tumors was reassessed. In addition, the presence of one of the pathognomonic gene translocations was confirmed, uniquely for a retrospective series. The surgical and oncological outcomes were reviewed. A comprehensive review of the literature was performed on the metastatic pattern of MLS, including series with 10 or more MLS patients with metastatic disease.

RESULTS

A total of 32 patients with genetically confirmed MLS were identified, with a median follow-up of 7.6 years. Seven patients (22%) developed metastatic disease, five initially intra-abdominally and only one to the lungs. The comprehensive review included 14 series with 1853 patients, 348 (19%) of whom had metastases. The location of the first metastases was soft tissues in 32% of patients, intra-abdominal in 26%, pulmonary in 24%, and bone in 17%.

CONCLUSIONS

MLSs metastasize often intra-abdominally and to extra-abdominal soft tissues. Thus, whole-body imaging may be indicated during the initial assessment and follow-up of these patients.

Artificial intelligence significantly improves the diagnostic accuracy of deep myxoid soft tissue lesions in histology

Deep myxoid soft tissue lesions have posed a diagnostic challenge for pathologists due to significant histological overlap and regional heterogeneity, especially when dealing with small biopsies which have profoundly low accuracy. However, accurate diagnosis is important owing to difference in biological behaviors and response to adjuvant therapy, that will guide the extent of surgery and the need for neo-adjuvant therapy. Herein, we trained two convolutional neural network models based on a total of 149,130 images representing diagnoses of extra skeletal myxoid chondrosarcoma, intramuscular myxoma, low-grade fibromyxoid sarcoma, myxofibrosarcoma and myxoid liposarcoma. Both AI models outperformed all the pathologists, with a significant improvement of accuracy up to 97% compared to average pathologists of 69.7% (p < 0.00001), corresponding to 90% reduction in error rate. The area under curve of the best AI model was on average 0.9976. It could assist pathologists in clinical practice for accurate diagnosis of deep soft tissue myxoid lesions, and guide clinicians for precise and optimal treatment for patients.

Fluorescence-Guided Visualization of Soft-Tissue Sarcomas by Targeting Vascular Endothelial Growth Factor A: A Phase 1 Single-Center Clinical Trial

Resection of soft-tissue sarcoma (STS) is accompanied by a high rate of tumor-positive surgical margins (14%-34%), which potentially lead to decreased disease-free survival. Vascular endothelial growth factor A is overexpressed in malignant tumors, including STS, and can be targeted with bevacizumab-800CW during fluorescence-guided surgery for real-time tumor detection. In this phase 1 clinical trial, we determined the feasibility, safety, and optimal dose of bevacizumab-800CW for fluorescence-guided surgery in STS for in vivo and ex vivo tumor detection. Methods: Patients with a histopathologic diagnosis of STS were included. In the dose-escalation phase, patients received bevacizumab-800CW intravenously 3 d before surgery (10, 25, and 50 mg; n = 8). In the subsequent dose-expansion phase, 7 additional patients received bevacizumab-800CW at the optimal dose. Fluorescence images were obtained in vivo and ex vivo during all stages of standard care. The optimal dose was determined by calculating in vivo and ex vivo tumor-to-background ratios (TBR) and correlating these results with histopathology. Results: Fifteen patients with STS completed this study. All tumors could be visualized during in vivo and ex vivo imaging. The optimal bevacizumab-800CW dose proved to be 10 mg, with a median in vivo TBR of 2.0 (±0.58) and a median ex vivo TBR of 2.67 (±1.6). All 7 tumor-positive margins could be observed in real time after surgical resection. Conclusion: GS using 10 mg of bevacizumab-800CW is feasible and safe for intraoperative imaging of STS, potentially allowing tumor detection and margin assessment during surgery. An additional follow-up phase 2 study is needed to confirm the diagnostic accuracy.

Time Trends and Prognostic Factors for Overall Survival in Myxoid Liposarcomas: A Population-Based Study

BACKGROUND

The purpose of this study was to evaluate the overall survival (OS) and associated characteristics for patients with Myxoid Liposarcoma (MLS) over time in The Netherlands.

METHODS

A population-based study was performed of patients with primary localized (n = 851) and metastatic (n = 50) MLS diagnosed in The Netherlands between 1989 and 2016, based on data from the National Cancer Registry.

RESULTS

The median age of the MLS patients was 49 years, and approximately two-thirds was located in the lower limb. An association was revealed between age and the risk of having a Round Cell (RC) tumor. OS rates for primary localized MLS were 93%, 83%, 78%, and 66% after 1, 3, 5, and 10 years, respectively. The median OS for patients with metastatic disease at diagnosis was 10 months. Increasing age (Hazard Ratio (HR) 1.05, p=0.00), a tumor size >5 cm (HR 2.18; p=0.00), and tumor location (trunk HR 1.29; p=0.09, upper limb HR 0.83; p=0.55, and "other" locations HR 2.73; p=0.00, as compared to lower limb) were independent prognostic factors for OS. The percentage of patients treated with radiotherapy (RT) increased over time, and preoperative RT gradually replaced postoperative RT. In contrast to patients with localized disease, significant improvement of OS was observed in patients with metastatic disease over time.

CONCLUSIONS

In this large nationwide cohort, tumor size and tumor location were independent prognostic factors for OS. Furthermore, a higher probability of an RC tumor with increasing age was suggested. An increased use of RT over the years did not translate into improved OS for localized MLS.

Impact of primary tumor location on outcome of liposarcoma patients, a retrospective cohort study

BACKGROUND

Tumor location as a prognostic factor for patients with liposarcoma (LPS) has been studied modestly with varying outcomes. The aim was to establish the impact of tumor location on recurrence and survival of LPS patients.

METHODS

A retrospective database of patients treated for LPS until December 2017 was used to assess 5-year local recurrence-free survival (LRFS), distant metastasis-free survival (DMFS) and disease-specific survival (DSS) per tumor location using the Kaplan-Meier method and log-rank test. A multivariable Cox regression analysis was performed to adjust for other prognostic factors.

RESULTS

In total, 518 patients were identified with a median follow-up of 68 months (interquartile range 31-138). Patients with retroperitoneal/intrathoracic WDLPS or DDLPS (p = 0.014), or testicular WDLPS (p = 0.026) developed a local recurrence more often than patients with other tumor locations. No differences between LPS subtypes and tumor location in the development of metastases (p = 0.600) was observed. Five-year LRFS differed significantly between tumor locations (p < 0.001) as well as 5y-DSS (p < 0.001), but 5y-DMFS did not (p = 0.241), with retroperitoneal/intrathoracic LPS having a worse prognosis. Patients with WDLPS in the extremity, trunk or testicular region did not die of disease, except for the rare occasion of dedifferentiation upon recurrence. After adjustment for other prognostic factors, tumor location was only of prognostic value for DSS (retroperitoneal/intrathoracic vs. extremity: HR 5.08, 95% CI 2.41-10.71, p < 0.001).

CONCLUSION

For all tumor locations, DSS mimicked DMFS except for retroperitoneal/intrathoracic LPS, where DSS mimicked LRFS and where DSS was worse than DMFS. This implies that these patients die of local disease instead of metastatic disease.

Adequate Local Control in High-Risk Soft Tissue Sarcoma of the Extremity Treated with Surgery Alone at a Reference Centre: Should Radiotherapy Still be a Standard?

BACKGROUND

Established practice for the management of soft tissue sarcoma (STS) of the extremity and trunk wall combines perioperative radiotherapy (RT) with limb-preserving surgery.

OBJECTIVE

The aim of this study was to explore whether high-quality surgery at high-volume centers may offer equivalent local control in selected cases, when RT needs to be avoided.

METHODS

All consecutive adult cases of primary, high-risk STSs treated in a high-volume reference center over a 12-year timeframe were included, and, on retrospective analysis, were divided into two groups. Group A received RT with surgery, and Group B received surgery alone. The primary endpoint was local recurrence-free survival (LRFS).

RESULTS

Overall, 390 patients were included (318 in Group A and 72 in Group B), with a median follow-up of 53 months. The main reasons for avoiding RT were patient choice and technical considerations (vascular bypass or flap reconstruction). No difference in R0 resection was seen between the groups (79% vs. 70%; p = 0.18), but Group A had more G3 tumors (80.5% vs. 68%; p = 0.021). No difference in 5-year LRFS was evident (84% vs. 81%; p = 0.16).

CONCLUSIONS

LRFS did not differ between patients with high-risk STSs receiving perioperative RT and those treated with surgery alone. The study was retrospective and omission of RT was largely uncontrolled with inherent bias. Nonetheless, data suggest that in experienced centers, the omission of RT did not diminish local disease outcome. Future studies on a selective approach to RT administration are awaited.

Neoadjuvant radiotherapy for myxoid liposarcomas: Oncologic outcomes and histopathologic correlations

OBJECTIVE

The aim of this study was to evaluate the histopathological features of primary extremity myxoid liposarcoma before and after neoadjuvant radiation therapy, and to evaluate the oncological outcomes of the patients.

METHODS

The study included 23 patients (16 men and 7 women with a mean age of 43 (24-69) years) with primary myxoid liposarcoma of the extremities, who were treated between January 1998 and December 2015. Inclusion criteria were histopathological confirmation of the diagnosis with both the initial biopsy and the resection specimen, and having undergone neoadjuvant radiotherapy. Demographic, clinical and histopathological data were evaluated.

RESULTS

Over a mean follow-up time of 55.2 (8-139) months, 5 patients (21.7%) died secondary to disease progression, leaving 18 patients (78.3%) still alive at the time of last follow-up. Only one patient (4%) experienced local recurrence and six (26%) patients developed distant metastases. Disease-free survival at 5 and 10 years were 66%; whereas, overall patient survival at 5 and 10 years were 78.1% and 71.0%, respectively. Tumor size (>15 cm) and presence of metastasis were significantly associated with increased overall mortality. On histopathology, necrosis was present in 12/23 resection specimens. Hyalinization/fibrosis and residual viable tumor was present in all specimens. Adipocytic maturation/cytodifferentiation was seen in 8/23 patients.

CONCLUSION

Neoadjuvant radiotherapy was effective for myxoid liposarcomas histopathologically, although these histopathological features did not affect the patients' oncological outcomes. Favorable oncological outcomes were obtained with neoadjuvant radiotherapy, surgical resection and chemotherapy.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

External Beam Radiation Therapy for Resectable Soft Tissue Sarcoma: A Systematic Review and Meta-Analysis

PURPOSE

The aim of this study was to evaluate the role of preoperative and postoperative external beam radiation therapy (EBRT) in the treatment of resectable soft tissue sarcomas (STSs) of different tumor locations.

METHODS

A systematic literature search was performed to identify studies investigating the effects of EBRT (versus no EBRT) on local recurrence (LR) and overall survival (OS) or comparing different EBRT sequences. Random effects meta-analyses were calculated and presented as cumulative odds ratios (ORs).

RESULTS

Sixteen studies (n = 3958 patients) comparing EBRT versus no EBRT, including one randomized controlled trial (RCT) in extremity sarcoma, were analyzed. EBRT appeared to reduce LR in both retroperitoneal tumors (OR 0.47, p < 0.0001) and other locations (OR 0.49, p = 0.001). OS was improved by EBRT in retroperitoneal STSs (OR 0.37, p < 0.0001) but not in other tumor locations. Eleven studies (n = 2140), including one RCT, compared preoperative and postoperative radiotherapy. LR was less frequent following preoperative EBRT in retroperitoneal STSs (OR 0.03, p = 0.02), as well as in other tumor locations (OR 0.67, p = 0.01), while wound complications in extremity sarcoma were more frequent following preoperative EBRT (OR 2.92, p < 0.0001). Several studies included in this meta-analysis bear a high risk of bias and no RCT has been published for retroperitoneal STS.

CONCLUSIONS

This meta-analysis supports the use of EBRT for local tumor control in patients with resectable STSs. Based on a small number of non-randomized studies, a positive effect on OS may exist in the subgroup of retroperitoneal STSs.

High-Throughput Screening of Myxoid Liposarcoma Cell Lines: Survivin Is Essential for Tumor Growth

Myxoid liposarcoma (MLS) is a soft tissue sarcoma characterized by a recurrent t(12;16) translocation. Although tumors are initially radio- and chemosensitive, the management of inoperable or metastatic MLS can be challenging. Therefore, our aim was to identify novel targets for systemic therapy. We performed an in vitro high-throughput drug screen using three MLS cell lines (402091, 1765092, DL-221), which were treated with 273 different drugs at four different concentrations. Cell lines and tissue microarrays were used for validation. As expected, all cell lines revealed a strong growth inhibition to conventional chemotherapeutic agents, such as anthracyclines and taxanes. A good response was observed to compounds interfering with Src and the mTOR pathway, which are known to be affected in these tumors. Moreover, BIRC5 was important for MLS survival because a strong inhibitory effect was seen at low concentration using the survivin inhibitor YM155, and siRNA for BIRC5 decreased cell viability. Immunohistochemistry revealed abundant expression of survivin restricted to the nucleus in all 32 tested primary tumor specimens. Inhibition of survivin in 402-91 and 1765-92 by YM155 increased the percentage S-phase but did not induce apoptosis, which warrants further investigation before application in the treatment of metastatic MLS. Thus, using a 273-compound drug screen, we confirmed previously identified targets (mTOR, Src) in MLS and demonstrate survivin as essential for MLS survival.