What Clinical Trials Are Needed for Treatment of Leiomyosarcoma?

Surgical outcomes of patients with inferior vena cava leiomyosarcoma

INTRODUCTION

Primary vascular leiomyosarcomas are incredibly rare and have a poor prognosis. The purpose of this study was to analyze the surgical outcomes of patients with primary inferior vena cava (IVC) leiomyosarcoma.

METHODS

We performed a retrospective review of IVC leiomyosarcoma resections performed at a single tertiary care hospital from 2014 to 2023. A total of 13 cases were analyzed, including 10 women and 3 men. The presenting symptoms, tumor characteristics, operative management, postoperative complications, and survival rates were assessed for each patient.

RESULTS

The median patient age was 59 years (quartile [Q]1, 52 years; Q3, 68 years). The median tumor size was 7.0 cm (Q1, 6 cm; Q3, 12 cm). The median mitotic rate was 6 per 10 high-power fields (Q1, 2.5; Q3, 15.5). All 13 patients underwent grossly negative tumor resection, with 9 (69%) having microscopically negative margins (R0). No patient had lymph node involvement. The IVCs were managed with ligation in four patients for tumors already occluding the IVC and bovine pericardial patch angioplasty in seven patients or primary repair in two patients for patent IVCs. Concomitant right nephrectomy was performed in seven patients. Left renal vein ligation was performed in three patients, but no left nephrectomies were performed. Significant postoperative complications included one patient with lower extremity compartment syndrome, two patients with severe leg swelling, and one patient with arm swelling. The 30-day mortality rate was zero. Using the Kaplan-Meier product limit method, disease-specific survival was estimated to be 93%.

CONCLUSIONS

Surgical resection is a feasible and effective oncologic treatment option for patients with IVC leiomyosarcoma. The IVC can be safely managed by ligation, primary repair, or patch angioplasty, depending on the prior patency of the IVC.

Establishment and characterization of NCC-LMS3-C1: a novel patient-derived cell line of leiomyosarcoma

Leiomyosarcoma (LMS) is an aggressive mesenchymal malignancy, which originates from the smooth muscle cells or from the precursor mesenchymal stem cells that potentially differentiate into smooth muscle cells. LMS is one of the most common sarcomas. LMS has genomic instability, reflecting complex and unbalanced karyotypes, and the cytogenetic and molecular changes in LMS are not consistent. The standard treatment of the primary LMS is complete resection, and the metastasis is often observed even after curative surgery. Patient-derived cancer models are a key bioresource to develop a novel therapy, and we aimed to establish and characterize a novel cell line for LMS. We established a cell line from tumor tissues of the patient with LMS and named it NCC-LMS3-C1. We maintained NCC-LMS3-C1 cells for 12 months and passed them more than 30 times. Genome-wide copy number analysis demonstrated that NCC-LMS3-C1 cells harbored genetic abnormalities. NCC-LMS3-C1 cells exhibited aggressive phenotypes such as continuous growth, spheroid formation, and invasion in the tissue culture condition, which may reflect the clinical behaviors of LMS. We performed a drug screening using NCC-LMS3-C1 cells and found that four anti-cancer agents, such as bortezomib, dasatinib, mitoxantrone, and romidepsin, had remarkable anti-proliferative effects on NCC-LMS3-C1 cells. We conclude that NCC-LMS3-C1 cells will be a useful resource for the study of LMS.

Hyper-Dependence on NHEJ Enables Synergy between DNA-PK Inhibitors and Low-Dose Doxorubicin in Leiomyosarcoma

PURPOSE

Leiomyosarcoma (LMS) is an aggressive sarcoma for which standard chemotherapies achieve response rates under 30%. There are no effective targeted therapies against LMS. Most LMS are characterized by chromosomal instability (CIN), resulting in part from TP53 and RB1 co-inactivation and DNA damage repair defects. We sought to identify therapeutic targets that could exacerbate intrinsic CIN and DNA damage in LMS, inducing lethal genotoxicity.

EXPERIMENTAL DESIGN

We performed clinical targeted sequencing in 287 LMS and genome-wide loss-of-function screens in 3 patient-derived LMS cell lines, to identify LMS-specific dependencies. We validated candidate targets by biochemical and cell-response assays in vitro and in seven mouse models.

RESULTS

Clinical targeted sequencing revealed a high burden of somatic copy-number alterations (median fraction of the genome altered =0.62) and demonstrated homologous recombination deficiency signatures in 35% of LMS. Genome-wide short hairpin RNA screens demonstrated PRKDC (DNA-PKcs) and RPA2 essentiality, consistent with compensatory nonhomologous end joining (NHEJ) hyper-dependence. DNA-PK inhibitor combinations with unconventionally low-dose doxorubicin had synergistic activity in LMS in vitro models. Combination therapy with peposertib and low-dose doxorubicin (standard or liposomal formulations) inhibited growth of 5 of 7 LMS mouse models without toxicity.

CONCLUSIONS

Combinations of DNA-PK inhibitors with unconventionally low, sensitizing, doxorubicin dosing showed synergistic effects in LMS in vitro and in vivo models, without discernable toxicity. These findings underscore the relevance of DNA damage repair alterations in LMS pathogenesis and identify dependence on NHEJ as a clinically actionable vulnerability in LMS.

Web-based nomograms for predicting overall survival and cancer-specific survival in retroperitoneal leiomyosarcoma: a population-based analysis

BACKGROUND

Retroperitoneal leiomyosarcoma is a type of carcinoma with low incidence and poor prognosis, and prognostic factors are currently unknown. Therefore, our study aimed to investigate the predictive factors of RPLMS and establish prognostic nomograms.

METHODS

Patients diagnosed with RPLMS between 2004 and 2017 were selected from the Surveillance, Epidemiology, and End Results (SEER) database. Prognostic factors were identified by univariate and multivariate COX regression analyses and used to generate nomograms to predict overall survival (OS) and cancer-specific survival (CSS).

RESULTS

646 eligible patients were randomly divided into training set (n = 323) and validation set (n = 323). Multivariate COX regression analysis indicated that the independent risk factors for OS and CSS were age, tumor size, grade, SEER stage, and surgery. In the nomogram of OS, the concordance indices (C-index) of the training and validation sets were 0.72 and 0.691, and in the nomogram of CSS, the C-indices of the training and validation sets were 0.737 and 0.737. Furthermore, calibration plots showed that the predicted results of the nomograms in the training and validation sets agree well with the actual observations.

CONCLUSION

Age, tumor size, grade, SEER stage, and surgery were independent prognostic factors for RPLMS. The nomograms developed and validated in this study can accurately predict the OS and CSS of patients, which could help clinicians make individualized survival predictions. Finally, we make the two nomograms into two web calculators for the convenience of clinicians.

Next questions in the management of retroperitoneal sarcoma

PURPOSE OF REVIEW

Retroperitoneal soft-tissue sarcomas (RPS) are a group of rare, histologically distinct tumours with variable recurrence patterns depending on histological type. This review will discuss the growing body of evidence supporting histology-specific, multidisciplinary management and highlight areas of future research for patients with RPS.

RECENT FINDINGS

Histology-tailored surgery is the cornerstone of management in patients with localized RPS. Further efforts to develop resectability criteria and identify patients who will benefit from neoadjuvant treatment strategies will help standardize the treatment of patients with localized RPS. Surgery for local recurrence is well tolerated in selected patients and re-iterative surgery in liposarcoma (LPS) may be beneficial at the time of local recurrence. The management of advanced RPS holds promise with several trials currently investigating systemic treatment beyond conventional chemotherapy.

SUMMARY

The management of RPS has made significant progress over the past decade owing to international collaboration. Ongoing efforts to identify patients who will derive the most benefit from all treatment strategies will continue to advance the field of RPS.