Management of advanced uterine leiomyosarcoma

High-Grade Sarcomas with Myogenic Differentiation Harboring Hotspot PDGFRB Mutations

PDGFRB-activating mutations have been reported in pediatric myofibroma and myofibromatosis. However, recurrent gain-of-function PDGFRB mutations have not been documented in sarcomas with myogenic differentiation. Driven by occasional sarcomas harboring PDGFRB mutations, we investigated their prevalence and clinicopathologic and genomic features in a large cohort of sarcomas. An institutional targeted DNA next-generation sequencing database was searched for sarcomas with myogenic differentiation harboring hotspot PDGFRB gene alterations. Among 3300 patients with sarcomas, 21 (0.6%) patients were identified (17 women, 4 men) with an age range of 35 to 88 years. The site distribution included 13 gynecologic tract (12 uteri, 1 vagina), 4 bone and soft tissue, and 4 viscera. All except 1 were high grade. Most patients were diagnosed as sarcomas with myogenic differentiation based on partial staining for 1 or more muscle markers, whereas 6 were labeled as leiomyosarcoma (LMS). Most tumors showed monomorphic spindle morphology, with either heterogeneous features of myofibroblastic and smooth muscle differentiation or an undifferentiated phenotype. Hormone receptors were negative in all uterine cases. PDGFRB immunostaining in all cases tested was strong and diffuse, whereas PDGFRA was negative/focal. The most frequent PDGFRB mutations were exon 12 (43%), exon 14 (N666K/S/T) (38%), and exon 18 (D850Y/H/V or insertion/deletion) (19%). The most frequent co-existing genetic alterations (26% to 37%) occurred in CDKN2A/B, TP53, TERT, and MED12. Moreover, PDGFRB-mutant sarcomas had an overall distinct genomic landscape compared with both uterine and soft tissue LMS control groups. These tumors were associated with a highly aggressive clinical course, with frequent distant metastases (81%) and death (76%), regardless of anatomic location, and worse overall survival compared with the 2 LMS control groups. This is the first study documenting recurrent hotspot PDGFRB alterations in high-grade sarcomas, which show a predilection for uterine location and myogenic differentiation that fall short of the diagnostic criteria for LMS. Further studies are needed to investigate the therapeutic potential of kinase inhibitors in this group of tumors.

Identification of Somatic Genetic Alterations Using Whole-Exome Sequencing of Uterine Leiomyosarcoma Tumors

Background

The genomic abnormalities associated with uterine leiomyosarcoma (uLMS) have not been fully elucidated to date.

Objective

To understand the pathogenesis of uLMS and to identify driver mutations and potential therapeutic targets in uLMS.

Methods

Three matched tumor-constitutional DNA pairs from patients with recurrent uLMS were subjected to whole-exome capture and next-generation sequencing. The role of the selected gene SHARPIN in uLMS was analyzed by the CCK-8 assay and colony formation assay after specific siRNA knockdown.

Results

We identified four genes with somatic SNVs, namely, SLC39A7, GPR19, ZNF717, and TP53, that could be driver mutations. We observed that 30.7% (4/13) of patients with uLMS had TP53 mutations as analyzed by direct sequencing. Analysis of somatic copy number variants (CNVs) showed regions of chromosomal gain at 1q21-23, 19p13, 17q21, and 17q25, whereas regions of chromosomal loss were observed at 2q35, 2q37, 1p36, 10q26, 6p22, 8q24, 11p15, 11q12, and 9p21. The SHARPIN gene was amplified in two patients and mutated in another (SHARPIN: NM_030974: exon2: c.G264C, p.E88D). Amplification of the SHARPIN gene was associated with shorter PFS and OS in soft tissue sarcoma, as shown by TCGA database analysis. Knockdown of SHARPIN expression was observed to decrease cell growth and colony formation in uterine sarcoma cell lines.

Conclusions

Exome sequencing revealed mutational heterogeneity of uLMS. The SHARPIN gene was amplified in uLMS and could be a candidate oncogene.

Stabilization of Metastatic Uterine Leiomyosarcoma Using Pembrolizumab

The estimated 5-year survival rate for patients with stage IV uterine leiomyosarcoma is 29%, with a median survival of <1 year. This report describes a patient with stage IVB leiomyosarcoma who experienced stable disease for 15 months on pembrolizumab. A woman aged 62 years, gravida 2 para 2, with postmenopausal bleeding and a necrotic uterine fibroid underwent a dilation and curettage and was diagnosed with uterine leiomyosarcoma. CT imaging showed pulmonary and bony metastasis. She underwent surgical staging with biopsy-proved stage IVB disease. A mixed partial response was noted using first- and second-line chemotherapy. Molecular tumor profiling confirmed PD-L1 expression. The patient was started on pembrolizumab, and at the time of writing she is status post 23 cycles with stable disease. Pembrolizumab was well tolerated and aided prolonged disease stabilization.

Hormonal therapy in uterine sarcomas

Uterine sarcomas (USs) are a group of rare but aggressive uterine malignancies, accounting for only 1% of the malignant tumors of female reproductive organs. Due to the high rate of recurrence and metastasis, the prognosis of USs is poor. Given the high mortality rate and limited clinical benefit of surgery and adjuvant chemoradiotherapy, hormonal therapy has shown good prospects in recent years. Hormonal agents include progestins, aromatase inhibitors (AIs), and gonadotropin‐releasing hormone analogue (GnRH‐a). According to the literature, hormonal therapy has been confirmed effective for recurrent, metastatic or unresectable low‐grade endometrial stromal sarcoma (LGESS) and hormone receptor positive (ER+/PR+) uterine leiomyosarcoma (uLMS) with favorable tolerance and compliance. Besides, hormonal therapy can also be used in patients with early‐staged disease who desire to preserve fertility. However, due to the rarity of USs, the rationale of hormonal therapy is generally extrapolated from data of hormone‐sensitive breast cancer, and present studies of hormonal therapy in USs were almost limited to case reports and small‐sized retrospective studies. Therefore, further systematic researches and standardized clinical trials are needed to establish the optimal hormonal therapy regimen of USs. Herein, we reviewed the existing studies related to the hormonal therapy in USs in order to provide reference for clinical management in specific settings.

Adjuvant Gemcitabine Plus Docetaxel Followed by Doxorubicin Versus Observation for High-Grade Uterine Leiomyosarcoma: A Phase III NRG Oncology/Gynecologic Oncology Group Study

PURPOSE

We conducted a randomized phase III trial to determine whether adjuvant chemotherapy improves survival in women with uterine leiomyosarcoma.

METHODS

Women with uterus-confined, high-grade leiomyosarcoma who were confirmed disease free by imaging were randomly assigned to four cycles of gemcitabine plus docetaxel, followed by four cycles of doxorubicin, or to observation. All were followed for evidence of recurrence. The primary end point was overall survival (OS).

RESULTS

With international collaboration, 38 of the targeted accrual of 216 patients were enrolled, after which the study was closed by the National Cancer Institute for accrual futility. Twenty patients were assigned to chemotherapy, 18 to observation. Among the 17 patients treated with at least one cycle of chemotherapy, grade 3 or 4 toxicities were observed in 47%; among the 18 patients assigned to observation, one had grade 3 hypertension. There were six deaths (chemotherapy, n = 5; observation, n = 1), all due to disease. The restricted mean survival time for OS was estimated as 34.3 months (95% CI, 25.3 to 43.3 months) in the chemotherapy arm and as 46.4 months (95% CI, 43.6 to 49.1 months) in the observation arm. There were eight recurrences in each arm. The restricted mean survival time for recurrence-free survival was estimated as 18.1 (95% CI, 14.2 to 22.0) months in the chemotherapy arm and as 14.6 months (95% CI, 10.3 to 19.0 months) in the observation arm. Neither survival outcome comparison was considered statistically robust, due to the small sample size.

CONCLUSION

Despite international collaboration to test the role of adjuvant chemotherapy in uterine-confined leiomyosarcoma, this study was closed for accrual futility. Although the sample size precludes robust statistical comparison, observed OS and recurrence-free survival data do not show superior outcomes with adjuvant chemotherapy.

Pulmonary metastasis from uterine leiomyosarcoma in a patient with limited cutaneous systemic scleroderma

A 51-year-old woman, who was diagnosed as having limited cutaneous systemic scleroderma, presented with pulmonary nodules incidentally detected in a chest radiograph. The patient had surgical biopsy of the nodules. In microscopic examination of the specimens, proliferation, mitotic activity, and cellular anaplasia of spindle cells were present. Fluorodeoxyglucose-positron emission tomography showed tumors in lungs as well as uterus. The diagnosis of the tumor was pulmonary metastases from uterine leiomyosarcoma. We should be on alert the possibility of developing malignant disease in patient with this autoimmune disease. If it is certain that there is metastasis, we believe that therapy for the primary lesion will be preceded by biopsy and surgery for the metastatic lesions.

Managing sarcoma: where have we come from and where are we going?

Sarcomas are a heterogeneous group of neoplasms of mesenchymal origin. Approximately 80% arise from soft tissue and 20% originate from bone. To date more than 100 sarcoma subtypes have been identified and they vary in molecular characteristics, pathology, clinical presentation and response to treatment. While sarcomas represent <1% of adult cancers, they account for approximately 21% of paediatric malignancies and thus pose some of the greatest risks of mortality and morbidity in children and young adults. Metastases occur in one-third of all patients and approximately 10-20% of sarcomas recur locally. Surgery in combination with preoperative and postoperative therapies is the primary treatment for localized sarcoma tumours and is the most promising curative possibility. Metastasized sarcomas, on the other hand, are treated primarily with single-agent or combination chemotherapy, but this rarely leads to a complete and robust response and often becomes a palliative form of treatment. The heterogeneity of sarcomas results in variable responses to current generalized treatment strategies. In light of this and the lack of curative strategies for metastatic and unresectable sarcomas, there is a need for novel subtype-specific treatment strategies. With the more recent understanding of the molecular mechanisms underlying the pathogenesis of some of these tumours, the treatment of sarcoma subtypes with targeted therapies is a rapidly evolving field. This review discusses the current management of sarcomas as well as promising new therapies that are currently underway in clinical trials.

Efficacy and safety of trabectedin or dacarbazine in patients with advanced uterine leiomyosarcoma after failure of anthracycline-based chemotherapy: Subgroup analysis of a phase 3, randomized clinical trial

OBJECTIVE

Trabectedin demonstrated significantly improved disease control in leiomyosarcoma and liposarcoma patients in a global phase 3 trial (NCT01343277). A post hoc analysis was conducted to assess the efficacy and safety of trabectedin or dacarbazine in women with uterine leiomyosarcoma (uLMS), the largest subgroup of enrolled patients (40%).

METHODS

Of 577 patients randomized 2:1 to receive trabectedin 1.5mg/m² by 24-hour IV infusion or dacarbazine 1g/m² by 20-120-minute IV infusion once every three weeks, 232 had uLMS (trabectedin: 144; dacarbazine: 88). The primary endpoint was overall survival (OS); secondary endpoints were progression-free survival (PFS), objective response rate (ORR), clinical benefit rate (CBR: complete responses+partial responses+stable disease [SD] for at least 18weeks), duration of response (DOR), and safety.

RESULTS

PFS for trabectedin was 4.0months compared with 1.5months for dacarbazine (hazard ratio [HR]=0.57; 95% CI 0.41-0.81; P=0.0012). OS was similar (trabectedin 13.4months vs. dacarbazine 12.9months, HR=0.89; 95% CI 0.65-1.24; P=0.51) between groups. ORR was 11% with trabectedin vs. 9% with dacarbazine (P=0.82). CBR for trabectedin was 31% vs. 18% with dacarbazine (P=0.05); median DOR was 6.5months for trabectedin vs. 4.1months for dacarbazine (P=0.32). Grade 3/4 treatment-emergent adverse events observed in ≥10% of patients in the trabectedin group included transient aminotransferase (aspartate/alanine) elevations, anemia, leukopenia, and thrombocytopenia.

CONCLUSIONS

In this post hoc subset analysis of patients with uLMS who had received prior anthracycline therapy, trabectedin treatment resulted in significantly longer PFS versus dacarbazine, with an acceptable safety profile. There was no difference in OS.

Incidental leiomyosarcoma found at the time of cesarean hysterectomy for morbidly adherent placenta

Background

Incidental leiomyosarcoma (LMS) is a rare diagnosis in pregnancy or in the puerperium. To our knowledge, this is the first case reported in the literature of incidental LMS after cesarean hysterectomy for morbidly adherent placenta.

Case

We present a case of a cesarean hysterectomy performed for a suspected morbidly adherent placenta in a patient with three prior cesarean deliveries, an anterior placenta previa and a fundal fibroid. Subsequent pathology identified a LMS on final specimen. The patient declined bilateral oophorectomy and removal of her remaining cervix. No chemotherapy or radiation was given for her presumed stage IB disease.

Conclusion

An incidental finding of a LMS is infrequent; the risk of recurrence is > 50% even if the sarcoma is removed in its entirety.

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Occult uterine sarcomas may be found even during cesarean hysterectomy.

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Imaging should be performed when a leiomyosarcoma is diagnosed postoperatively.

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Recurrence risk can be > 50% even if a leiomyosarcoma is confined to the uterus.

Uterine leiomyosarcoma: a review of recent advances in molecular biology, clinical management and outcome

Uterine leiomyosarcoma (LMS) are rare but aggressive tumours with poor clinical outcomes regardless of stage. Most tumours are identified by histopathology at time of surgery, and pre-operative diagnosis remains a clinical challenge. Management of early-stage LMS relies on surgical resection. Cytotoxic chemotherapy remains the mainstay of therapy for advanced-stage, recurrent or metastatic LMS, and includes single or combination doxorubicin-, ifosfamide- or gemcitabine-based regimens. Recent interest in genetic biomarkers led to developments of targeted therapies for LMS, although more research is needed to understand the molecular complexities underlying LMS to guide the development of novel treatment strategies.

TWEETABLE ABSTRACT

The diagnosis and treatment of uterine LMS is challenging. Novel biomarkers offer hope for future therapies.

Survival of patients with metastatic leiomyosarcoma: the MD Anderson Clinical Center for targeted therapy experience

Advanced stage leiomyosarcoma (LMS) is incurable with current systemic antitumor therapies. Therefore, there is clinical interest in exploring novel therapeutic regimens to treat LMS. We reviewed the medical records of 75 consecutive patients with histologically confirmed metastatic LMS, who had been referred to the Clinical Center for Targeted Therapy at MD Anderson Cancer Center. To lay the foundation for potential phase I trials for the treatment of advanced LMS, we analyzed tumor response and survival outcome data. The frequent hotspot gene aberrations that we observed were the TP53 mutation (65%) and RB1 loss/mutation (45%) detected by Sequenom or next-generation sequencing. Among patients treated with gene aberration-related phase I trial therapy, the median progression-free survival was 5.8 months and the median overall survival was 15.9 months, significantly better than in patients without therapy (1.9 months, P = 0.001; and 8.7 months, P = 0.013, respectively). Independent risk factors that predicted shorter overall survival included hemoglobin <10 g/dL, body mass index <30 kg/m2 , serum albumin <3.5 g/dL, and neutrophil above upper limit of normal. The median survivals were 19.9, 7.6, and 0.9 months for patients with 0, 1 or 2, and ≥3 of the above risk factors, respectively (P < 0.001). A prognostic scoring system that included four independent risk factors might predict survival in patients with metastatic LMS who were treated in a phase I trial. Gene aberration-related therapies led to significantly better clinical benefits, supporting that further exploration with novel mechanism-driven therapeutic regimens is warranted.

Pioglitazone induces cell growth arrest and activates mitochondrial apoptosis in human uterine leiomyosarcoma cells by a peroxisome proliferator-activated receptor γ-independent mechanism

The peroxisome proliferator-activated receptor γ (PPARγ) agonists, thiazolidinediones, including pioglitazone (PIO) exhibit anti-tumour activities in cancer cells. The present study investigates the effects of PIO on cell proliferation and apoptosis in SK-UT-1 cells, a human uterine leiomyosarcoma cell line, and human uterine smooth muscle cells (HUtSMC). The proliferation and viability of SK-UT-1 cells treated with vehicle or PIO were assessed by cell counting and WST-1 assay. The activity of MEK/ERK and p38 MAPK signalling pathways and the expression of p53, the cyclin-dependent kinase inhibitor, p21, Bax, Bad and Bim proteins and cleaved caspase-3 were analysed by Western blotting. Quiescent SK-UT-1 cells intensively proliferate and display high levels of phosphorylated, activated MEK1/2, ERK1/2 and p38 MAPK. PIO (10 or 25 μM) induced time- and dose-dependently cell-growth arrest, reduced the cell numbers and effectively suppressed the over-activated MEK/ERK and p38 MAPK signalling pathways as evidenced by the abolished levels of phosphorylated MEK1/2, ERK1/2 and p38 MAPK. PIO activated the intrinsic apoptotic pathway, i.e. up-regulated the p53, p21, Bax and Bad proteins and cleaved caspase-3. PIO also reduced cell numbers of highly proliferative SK-UT-1 cells cultured in growth medium. The anti-proliferative and pro-apoptotic actions of PIO were not PPARγ dependent and exclusive for SK-UT-1 cells as PIO did not interfere with the proliferation of HUtSMC. The pronounced anti-tumorigenic effects of PIO in SK-UT-1 cells address an important issue about the relevance of the PPARγ agonist in the treatment of the human uterine leiomyosarcoma.

Potential Therapeutic Targets in Uterine Sarcomas

Uterine sarcomas are rare tumors accounting for 3,4% of all uterine cancers. Even after radical hysterectomy, most patients relapse or present with distant metastases. The very limited clinical benefit of adjuvant cytotoxic treatments is reflected by high mortality rates, emphasizing the need for new treatment strategies. This review summarizes rising potential targets in four distinct subtypes of uterine sarcomas: leiomyosarcoma, low-grade and high-grade endometrial stromal sarcoma, and undifferentiated uterine sarcoma. Based on clinical reports, promising approaches for uterine leiomyosarcoma patients include inhibition of VEGF and mTOR signaling, preferably in combination with other targeted or cytotoxic compounds. Currently, the only targeted therapy approved in leiomyosarcoma patients is pazopanib, a multitargeted inhibitor blocking VEGFR, PDGFR, FGFR, and c-KIT. Additionally, preclinical evidence suggests effect of the inhibition of histone deacetylases, tyrosine kinase receptors, and the mitotic checkpoint protein aurora kinase A. In low-grade endometrial stromal sarcomas, antihormonal therapies including aromatase inhibitors and progestins have proven activity. Other potential targets are PDGFR, VEGFR, and histone deacetylases. In high-grade ESS that carry the YWHAE/FAM22A/B fusion gene, the generated 14-3-3 oncoprotein is a putative target, next to c-KIT and the Wnt pathway. The observation of heterogeneity within uterine sarcoma subtypes warrants a personalized treatment approach.