Treatment of De-Differentiated Liposarcoma in the Era of Immunotherapy.

Well-differentiated/de-differentiated liposarcoma (WDLPS/DDLPS) is one of the most common histologic subtypes of soft tissue sarcoma (STS); however, treatment options remain limited. WDLPS and DDLPS both exhibit the characteristic amplification of chromosome region 12q13-15, which contains the genes CDK4 and MDM2. DDLPS exhibits higher amplification ratios of these two and carries additional genomic lesions, including the amplification of chromosome region 1p32 and chromosome region 6q23, which may explain the more aggressive biology of DDLPS. WDLPS does not respond to systemic chemotherapy and is primarily managed with local therapy, including multiple resections and debulking procedures whenever clinically feasible. In contrast, DDLPS can respond to chemotherapy drugs and drug combinations, including doxorubicin (or doxorubicin in combination with ifosfamide), gemcitabine (or gemcitabine in combination with docetaxel), trabectedin, eribulin, and pazopanib. However, the response rate is generally low, and the response duration is usually short. This review highlights the clinical trials with developmental therapeutics that have been completed or are ongoing, including CDK4/6 inhibitors, MDM2 inhibitors, and immune checkpoint inhibitors. This review will also discuss the current landscape in assessing biomarkers for identifying tumors sensitive to immune checkpoint inhibitors.

Case series of MET exon 14 skipping mutation-positive non-small-cell lung cancers with response to crizotinib and cabozantinib.

The mesenchymal-to-epithelial transition (MET) gene is altered and becomes a driver mutation in up to 5% of non-small-cell lung cancer (NSCLC). We report our institutional experience treating patients with MET exon 14 skipping (METex14) mutations, including responses to the MET inhibitors crizotinib and cabozantinib. We identified cases of NSCLC with METex14 mutations using an institutionally developed or commercial next-generation sequencing assay. We assessed patient and disease characteristics by retrospective chart review. Some patients were treated off-label by the physician with crizotinib or cabozantinib, and tumor responses to these agents were assessed. A total of 15 patients with METex14-mutated NSCLC were identified, predominantly male (n=10) with a smoking history (60%) and a median age of 74.0 years. No other actionable somatic mutations were detected. Stage distribution included 26.7% stage I, 6.7% stage II, 6.7% stage III, and 60.0% stage IV. Among patients treated with crizotinib or cabozantinib (n=6), three patients showed partial response and one patient showed stable disease on the basis of RECIST criteria. Four patients experienced side effects requiring drug holiday, reduction, or cessation. Our findings highlight the diversity in presentation and histology of NSCLC with METex14 mutations, which were found in the absence of other actionable driver mutations. We observed evidence of tumor response to crizotinib and cabozantinib, supporting the previous reports that METex14 mutations in NSCLC are actionable driver events.

Brg1 governs distinct pathways to direct multiple aspects of mammalian neural crest cell development.

Development of the cerebral vessels, pharyngeal arch arteries (PAAs). and cardiac outflow tract (OFT) requires multipotent neural crest cells (NCCs) that migrate from the neural tube to target tissue destinations. Little is known about how mammalian NCC development is orchestrated by gene programming at the chromatin level, however. Here we show that Brahma-related gene 1 (Brg1), an ATPase subunit of the Brg1/Brahma-associated factor (BAF) chromatin-remodeling complex, is required in NCCs to direct cardiovascular development. Mouse embryos lacking Brg1 in NCCs display immature cerebral vessels, aberrant PAA patterning, and shortened OFT. Brg1 suppresses an apoptosis factor, Apoptosis signal-regulating kinase 1 (Ask1), and a cell cycle inhibitor, p21(cip1), to inhibit apoptosis and promote proliferation of NCCs, thereby maintaining a multipotent cell reservoir at the neural crest. Brg1 also supports Myosin heavy chain 11 (Myh11) expression to allow NCCs to develop into mature vascular smooth muscle cells of cerebral vessels. Within NCCs, Brg1 partners with chromatin remodeler Chromodomain-helicase-DNA-binding protein 7 (Chd7) on the PlexinA2 promoter to activate PlexinA2, which encodes a receptor for semaphorin to guide NCCs into the OFT. Our findings reveal an important role for Brg1 and its downstream pathways in the survival, differentiation, and migration of the multipotent NCCs critical for mammalian cardiovascular development.

Sex-dependent Prognosis of Patients with Advanced Soft Tissue Sarcoma.

PURPOSE: To examine whether overall survival (OS) differs for male and female patients with advanced soft-tissue sarcoma (STS). EXPERIMENTAL DESIGN: The study included patients from Kaiser Permanente Northern California and Stanford Cancer Center with grade 2 and 3 locally advanced or metastatic STS whose tumor underwent next-generation sequencing. We used Cox regression modeling to examine association of sex and OS adjusting for other important factors. RESULTS: Among 388 eligible patients, 174 had leiomyosarcoma (LMS), 136 had undifferentiated pleomorphic sarcoma (UPS), and 78 had liposarcoma. OS for male versus female patients appeared to be slightly better among the full cohort [HR = 0.89; 95% confidence interval (CI), 0.66-1.20]; this association appeared to be stronger among the subsets of patients with LMS (HR = 0.76; 95% CI, 0.39-1.49) or liposarcoma (HR = 0.74; 95% CI, 0.32-1.70). Better OS for male versus female patients was also observed among all molecular subgroups except mutRB1 and mutATRX, especially among patients whose tumor retained wtTP53 (HR = 0.73; 95% CI, 0.44-1.18), wtCDKN2A (HR = 0.85; 95% CI, 0.59-1.23), wtRB1 (HR = 0.73; 95% CI, 0.51-1.04), and among patients whose tumor had mutPTEN (HR = 0.37; 95% CI, 0.09-1.62). OS also appeared to be better for males in the MSK-IMPACT and TCGA datasets. CONCLUSIONS: A fairly consistent pattern of apparent better OS for males across histologic and molecular subgroups of STS was observed. If confirmed, our results could have implications for clinical practice for prognostic stratification and possibly treatment tailoring as well as for future clinical trials design.

Efficacy and safety profile of combining agents against epidermal growth factor receptor or vascular endothelium growth factor receptor with gemcitabine-based chemotherapy in patients with advanced pancreatic cancer: a meta-analysis.

OBJECTIVES: Several clinical trials have been published on gemcitabine-based chemotherapy with or without addition of agents against epidermal growth factor receptor (EGFR) or vascular endothelium growth factor receptor (VEGFR) in patients with advanced pancreatic cancer, however, with diverse results. The objective of this study was to perform a meta-analysis of the published trials. METHODS: The database of CENTRAL, MEDLINE and EMBASE were searched. Eligible studies were randomized clinical trials (RCTs) that evaluated the efficacy and safety profile of adding targeted agents against EGFR or VEGFR to gemcitabine-based chemotherapy in patients with advanced pancreatic cancer. The primary outcome was overall survival (OS) while secondary outcomes included progression free survival (PFS) and overall response rate (ORR). Toxicity profiles were also assessed. Review Manager 5.1 was used to perform the analysis. RESULTS: Results reported from 6 RCTs involving 2733 patients were included in the analysis. Compared to gemcitabine-based chemotherapy alone, addition of an agent against EGFR resulted in significant longer OS [Hazard ratios (HR) 0.89 (0.79-0.99), p = 0.04] and longer PFS [HR 0.87 (0.79-0.97), p = 0.01], but no significant difference in ORR [RR 1.18 (0.82-1.70), p = 0.36]. The addition of an agent against VEGFR resulted in higher ORR [RR 1.54 (1.03-2.30), p = 0.04], but no advantage in OS [HR 0.95 (0.83-1.09), p = 0.47] or PFS [HR 0.97 (0.77-1.23), p = 0.82]. CONCLUSIONS: Addition of an agent against EGFR to gemcitabine-based chemotherapy improved OS compared to gemcitabine-based chemotherapy alone in patients with advanced pancreatic cancer, while addition of an agent against VEGFR showed a modest improvement in ORR but not PFS and OS.

Sex- and Co-Mutation-Dependent Prognosis in Patients with SMARCA4-Mutated Malignancies.

BACKGROUND: Whether sex and co-mutations impact prognosis of patients with SMARCA4-mutated (mutSMARCA4) malignancies is not clear. METHODS: This cohort included patients from Northern California Kaiser Permanente with next-generation sequencing (NGS) performed from August 2020 to October 2022. We used Cox regression modeling to examine the association between sex and overall survival (OS), adjusting for demographics, performance status, Charlson comorbidity index, receipt of treatment, tumor mutation burden (TMB), and TP53, KRAS, CDKN2A, STK11, and Keap1 co-mutations. RESULTS: Out of 9221 cases with NGS performed, 125 cases (1.4%) had a mutSMARCA4. The most common malignancies with a mutSMARCA4 were non-small cell lung cancer (NSCLC, 35.2%), esophageal and stomach adenocarcinoma (12.8%), and cancer of unknown primary (11.2%). The most common co-mutations were p53 (mutp53, 59.2%), KRAS (mutKRAS, 28.8%), CDKN2A (mutCDKN2A, 31.2%), STK11 (mutSTK11, 12.8%), and Keap1 (mutKeap1, 8.8%) mutations. Male patients had substantially worse OS than female patients both among the entire mutSMARCA4 cohort (HR = 1.71, [95% CI 0.92-3.18]) with a median OS of 3.0 versus 43.3 months (p < 0.001), and among the NSCLC subgroup (HR = 14.2, [95% CI 2.76-73.4]) with a median OS of 2.75 months versus un-estimable (p = 0.02). Among all patients with mutSMARCA4, mutp53 versus wtp53 (HR = 2.12, [95% CI 1.04-4.29]) and mutSTK11 versus wtSTK11 (HR = 2.59, [95% CI 0.87-7.73]) were associated with worse OS. Among the NSCLC subgroup, mutp53 versus wtp53 (HR = 0.35, [0.06-1.97]) and mutKRAS versus wtKRAS (HR = 0.04, [0.003-.45]) were associated with better OS, while mutCDKN2A versus wtCDKN2A (HR = 5.04, [1.12-22.32]), mutSTK11 versus wtSTK11 (HR = 13.10, [95% CI 1.16-148.26]), and mutKeap1 versus wtKeap1 (HR = 5.06, [95% CI 0.89-26.61}) were associated with worse OS. CONCLUSION: In our cohort of patients with mutSMARCA4, males had substantially worse prognosis than females, while mutTP53, mutKRAS, mutCDKN2A, mutSTK11 and mutKeap1were differentially associated with prognosis among all patients and among the NSCLC subgroup. Our results, if confirmed, could suggest potentially unidentified mechanisms that underly this sex and co-mutation-dependent prognostic disparity among patients whose tumor bears a mutSMARCA4.

High-dimensional single-cell analysis unveils distinct immune signatures of peripheral blood in patients with pancreatic ductal adenocarcinoma.

Introduction: Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies with poor response to immune checkpoint inhibitors. The mechanism of such poor response is not completely understood. Methods: We assessed T-cell receptor (TCR) repertoire and RNA expression at the single-cell level using high-dimensional sequencing of peripheral blood immune cells isolated from PDAC patients and from healthy human controls. We validated RNA-sequencing data by performing mass cytometry (CyTOF) and by measuring serum levels of multiple immune checkpoint proteins. Results: We found that proportions of T cells (CD45+CD3+) were decreased in PDAC patients compared to healthy controls, while proportion of myeloid cells was increased. The proportion of cytotoxic CD8+ T cells and the level of cytotoxicity per cell were increased in PDAC patients, with reduced TCR clonal diversity. We also found a significantly enriched S100A9+ monocyte population and an increased level of TIM-3 expression in immune cells of peripheral blood in PDAC patients. In addition, the serum level of soluble TIM-3 (sTIM-3) was significantly higher in PDAC patients compared to the non-PDAC participants and correlated with worse survival in two independent PDAC cohorts. Moreover, sTIM-3 exhibited a valuable role in diagnosis of PDAC, with sensitivity and specificity of about 80% in the training and validation groups, respectively. We further established an integrated model by combining sTIM-3 and carbohydrate antigen 19- 9 (CA19-9), which had an area under the curve of 0.974 and 0.992 in training and validation cohorts, respectively. Conclusion: Our RNA-seq and proteomic results provide valuable insight for understanding the immune cell composition of peripheral blood of patients with PDAC.

TP53 Gain-of-Function and Non-Gain-of-Function Mutations Are Associated With Differential Prognosis in Advanced Pancreatic Ductal Adenocarcinoma.

PURPOSE: To examine the impact of TP53 gain-of-function (GOF) and non-GOF mutations on prognosis of advanced pancreatic ductal adenocarcinoma (PDAC) among patients with KRAS, CDKN2A, and SMAD4 comutations. METHODS: This cohort included patients with locally advanced, recurrent, and de novo metastatic PDAC with next-generation sequencing performed from November 2017 to May 2022. We defined R175H, R248W, R248Q, R249S, R273H, R273L, and R282W as GOF and all other p53 mutations (mutp53) as non-GOF. We used Cox regression modeling to examine the association between GOF and non-GOF mutp53 and overall survival (OS), adjusting for demographics, performance status, Charlson comorbidity index, receipt of chemotherapy, and KRAS, CDKN2A, and SMAD4 comutations. RESULTS: Of 893 total eligible patients, 68.5% had tumors with mutp53, 90.1% had KRAS mutations (mutKRAS), 44.7% had CDKN2A mutations (mutCDKN2A), and 17.0% had SMAD4 mutations. Among patients with mutp53, 121 had GOF and 491 had non-GOF. GOF mutp53 was associated with worse OS than non-GOF mutp53 (hazard ratio [HR], 1.27; 95% CI, 1.02 to 1.59) and wild-type p53 (wtp53; HR, 1.24; 95% CI, 0.98 to 1.57), whereas non-GOF was not associated with worse OS than wtp53 (HR, 0.95; 95% CI, 0.80 to 1.13). In addition, mutKRAS was associated with worse OS than wild-type KRAS in patients with mutCDKN2A (HR, 1.57; 95% CI, 0.88 to 2.80) but not in patients with wild-type CDKN2A (HR, 1.03; 95% CI, 0.76 to 1.39). CONCLUSION: GOF and non-GOF mutp53 were associated with differential prognosis in advanced PDAC. The adverse effect of mutKRAS on OS appeared to be primarily driven by patients with mutCDKN2A. Our results provide new insight that could be helpful for prognostic stratification in clinical practice and for aiding future clinical trial designs.

Pain as Initial Presenting Symptom Is Associated With Delay to Seeking Medical Attention, Higher Risk of Relapse, and Shorter Survival in Patients With Early-Stage Extremity or Trunk Synovial Sarcoma.

BackgroundWhether the presenting symptom of pain vs mass impacts survival of early-stage synovial sarcoma is not known. Patients and MethodsThe authors investigated patients with early-stage extremity/trunk synovial sarcoma diagnosed from 2005 to 2017 at Kaiser Permanente Northern California for associations between the presenting symptom and survival. ResultsAmong 56 patients with early-stage extremity/trunk synovial sarcoma, median disease-free survival (DFS) was 20.3 months for the pain-only group (n = 19) vs 50.5 months for the mass ± pain group (n = 37) (p = 0.004), and median overall survival (OS) was 35.7 months vs 53.9 months (p = 0.009), respectively. Median DFS was 26.9 months for the pain ± mass group (n = 32) vs 48.6 months for the mass-only group (n = 24) (p = 0.047), whereas OS was not significantly different (49.6 vs. 53.6 months, p = 0.282). Pain at presentation was associated with a higher incidence of deep tumors and a higher risk of relapse. Cox regression model adjusting for age, sex, race, tumor location, tumor size, and wait-time to seek medical attention showed that pain at presentation was associated with 3-fold worse DFS and OS. ConclusionPain at presentation was an adverse risk factor for patients with early-stage extremity/trunk synovial sarcoma.

A Multicenter Virtual Multidisciplinary Sarcoma Case Conference Improves Outcome for a Rare Soft Tissue Sarcoma (Dermatofibrosarcoma Protuberans).

INTRODUCTION: The purpose of this study is to analyze the impact of a virtual multidisciplinary sarcoma case conference (VMSCC) on the outcomes of dermatofibrosarcoma protuberans (DFSP). METHODS: We compared margin status after surgery and disease-free survival (DFS) on two cohorts of patients with DFSP, one diagnosed from 2010 to 2015 and one from 2016 to 2020 (before and after virtual multidisciplinary sarcoma case conference (VMSCC) within Kaiser Permanente Northern California (KPNC), using Kaplan-Meier curves and Cox proportional hazard regression models. RESULTS: There was no significant difference between the two cohorts on demographics, tumor location, type of surgery, receipt of radiation, receipt of imatinib, or size of tumor. However, the percent of patients with positive margin after final surgery and the percent of local recurrence were significantly different: 6.5% and 6.3% for the 2010-2015 cohort, and .8% and 0% for the 2016-2020 cohort, respectively. CONCLUSION: Our data suggest that the outcomes of DFSP improved significantly after the implementation of VMSCC.

TP53 Gain-of-Function and Non-Gain-of-Function Mutations Are Differentially Associated With Sidedness-Dependent Prognosis in Metastatic Colorectal Cancer.

PURPOSE: To examine the association of gain-of-function (GOF) and non-gain-of-function (non-GOF) TP53 mutations with prognosis of metastatic right-sided (RCC) versus left-sided colorectal cancer (LCC). METHODS: This cohort study included patients with metastatic colorectal cancer (CRC) who had next-generation sequencing performed from November 2017 to January 2021. We defined R175H, R248W, R248Q, R249S, R273H, R273L, and R282W as GOF and all other mutp53 as non-GOF. We used Cox regression modeling to examine the association between GOF and non-GOF mutp53 and overall survival (OS), adjusting for age, sex, ethnicity, performance status, Charlson comorbidity index and receipt of chemotherapy. RESULTS: Of total 1,043 patients, 735 had tumors with mutp53 and 308 had wild-type p53 (wtp53). GOF was associated with worse OS than non-GOF mutp53 only in LCC (hazard ratio [HR] = 1.66 [95% CI, 1.20 to 2.29]), but not in RCC (HR = 0.79 [95% CI, 0.49 to 1.26]). Importantly, RCC was associated with worse OS than LCC only in the subset of patients whose CRC carried non-GOF (HR = 1.76 [95% CI, 1.30 to 2.39]), but not GOF mutp53 (HR = 0.92 [95% CI, 0.55 to 1.53]) or wtp53 (HR = 0.88 [95% CI, 0.60 to 1.28]). These associations were largely unchanged after also adjusting for RAS, BRAF, and PIK3CA mutations, and microsatellite instability-high. CONCLUSION: Poorer survival of patients with metastatic RCC versus LCC appeared to be restricted to the subset with non-GOF mutp53, whereas GOF versus non-GOF mutp53 was associated with poorer survival only among patients with LCC. This approach of collectively classifying mutp53 into GOF and non-GOF provides new insight for prognostic stratification and for understanding the mechanism of sidedness-dependent prognosis. If confirmed, future CRC clinical trials may benefit from incorporating this approach.

Calcineurin/NFAT signaling in osteoblasts regulates bone mass.

Development and repair of the vertebrate skeleton requires the precise coordination of bone-forming osteoblasts and bone-resorbing osteoclasts. In diseases such as osteoporosis, bone resorption dominates over bone formation, suggesting a failure to harmonize osteoclast and osteoblast function. Here, we show that mice expressing a constitutively nuclear NFATc1 variant (NFATc1(nuc)) in osteoblasts develop high bone mass. NFATc1(nuc) mice have massive osteoblast overgrowth, enhanced osteoblast proliferation, and coordinated changes in the expression of Wnt signaling components. In contrast, viable NFATc1-deficient mice have defects in skull bone formation in addition to impaired osteoclast development. NFATc1(nuc) mice have increased osteoclastogenesis despite normal levels of RANKL and OPG, indicating that an additional NFAT-regulated mechanism influences osteoclastogenesis in vivo. Calcineurin/NFATc signaling in osteoblasts controls the expression of chemoattractants that attract monocytic osteoclast precursors, thereby coupling bone formation and bone resorption. Our results indicate that NFATc1 regulates bone mass by functioning in both osteoblasts and osteoclasts.

Activation of NFAT signaling in podocytes causes glomerulosclerosis.

Mutant forms of TRPC6 can activate NFAT-dependent transcription in vitro via calcium influx and activation of calcineurin. The same TRPC6 mutants can cause FSGS, but whether this involves an NFAT-dependent mechanism is unknown. Here, we generated mice that allow conditional induction of NFATc1. Mice with NFAT activation in nascent podocytes in utero developed proteinuria and glomerulosclerosis postnatally, resembling FSGS. NFAT activation in adult mice also caused progressive proteinuria and FSGS. Ultrastructural studies revealed podocyte foot process effacement and deposition of extracellular matrix. NFAT activation did not initially affect expression of podocin, synaptopodin, and nephrin but reduced their expression as glomerular injury progressed. In contrast, we observed upregulation of Wnt6 and Fzd9 in the mutant glomeruli before the onset of significant proteinuria, suggesting a potential role for Wnt signaling in the pathogenesis of NFAT-induced podocyte injury and FSGS. These results provide in vivo evidence for the involvement of NFAT signaling in podocytes, proteinuria, and glomerulosclerosis. Furthermore, this study suggests that NFAT activation may be a key intermediate step in the pathogenesis of mutant TRPC6-mediated FSGS and that suppression of NFAT activity may contribute to the antiproteinuric effects of calcineurin inhibitors.

Rapid Response of a BRCA2/TP53/PTEN-Deleted Metastatic Uterine Leiomyosarcoma to Olaparib: A Case Report.

None: Patients with metastatic uterine leiomyosarcoma (uLMS) have poor prognosis due to limited treatment options, especially when disease progresses on doxorubicin and gemcitabine-docetaxel regimens. Here we report a patient whose metastatic uLMS contains a BRCA2 deep deletion as well as TP53 and PTEN deep deletion. The patient responded rapidly to olaparib, a poly (ADP-ribose) polymerase inhibitor, after progressing on gemcitabine-docetaxel, doxorubicin, and temozolomide regimens. This case report shall be helpful to the treatment of other patients with metastatic uLMS that harbors a BRCA2 mutation or deletion.

Impact of a Virtual Multidisciplinary Sarcoma Case Conference on Treatment Plan and Survival in a Large Integrated Healthcare System.

PURPOSE: Quantifying the impact of a multidisciplinary cancer case conference on patient outcome and care quality remains challenging. PATIENTS AND METHODS: We prospectively investigated the impact of our virtual multidisciplinary sarcoma case conference (VMSCC) on treatment plan in patients presented to the VMSCC from July to October 2020 (prospective cohort) and retrospectively in patients with metastatic or locally advanced high-grade soft-tissue sarcoma (STS) reviewed in the VMSCC in 2016 and 2017 (high-grade STS cohort). We also investigated the factors related to the nonadherence to the VMSCC-recommended plan in both cohorts. RESULTS: In both cohorts, approximately 28% of the patients were referred to the VMSCC for review without a treatment plan. In significantly more cases, referring physicians outside of the sarcoma group did not have a plan formulated before the VMSCC review compared with the referring physicians within the sarcoma group. In 28.2% (prospective cohort) and 19.5% (high-grade STS cohort) of the patients, VMSCC recommended a different plan. The adherence to the VMSCC-recommended plan was 87.9% and 83.1%, respectively. The causes of the nonadherence were primarily due to disease progression or patient's decision against recommended therapy. The median overall survival for the high-grade STS cohort was 26 months. CONCLUSION: VMSCC affected the treatment plan in approximately 50% of the patients in both cohorts. The median overall survival of the patients with high-grade STS reviewed by the VMSCC in our cohort is comparable with the literature.

Fourteen-Day Gemcitabine-Docetaxel Chemotherapy Is Effective and Safer Compared to 21-Day Regimen in Patients with Advanced Soft Tissue and Bone Sarcoma.

Gemcitabine-docetaxel (G-D) combination is an effective chemotherapy for patients with advanced soft tissue and bone sarcoma, first developed with G administered on days 1 and 8, and D on day 8 every 21 days and later modified to be administered every 14 days in 2012. The 14-day regimen has become increasingly adopted. However, its efficacy and toxicities have not been compared. We identified 161 patients with metastatic or locally advanced soft tissue and bone sarcoma treated with either a 14-day or 21-day regimen within Northern California Kaiser Permanente from 1 January 2017 to 30 July 2020 and compared the outcomes and toxicity profiles of patients treated with the either regimen. Seventy-nine (49%) and 82 (51%) patients received the 14-day and the 21-day regimen, respectively, with similar response rate (22.8% and 15.8%, p = 0.26), median progression-free survival (PFS, 4.0 and 3.2 months, p = 0.15), and median overall survival (OS, 12.6 and 14.7 months, p = 0.55). Subset analysis of the untreated patients (approximately 60% of the entire cohort) as well as the patients with leiomyosarcoma only (approximately 50% of the entire cohort) showed that OS was not significantly different between the two regimens. Febrile neutropenia requiring hospitalization occurred in 10 and one patients (p = 0.006) and intolerance leading to discontinuation of chemotherapy occurred in 12 and two patients (p = 0.006) treated with the 21-day and the 14-day regimens, respectively. CDKN2A deletion/mutation or CDK4 amplification was associated with worse median OS (p = 0.06), while a RB1 deletion/mutation was associated with better median PFS (p = 0.05), and these two genomic alterations were mutually exclusive. Our data demonstrate that, compared to the traditional 21-day G-D regimen, the 14-day G-D regimen is equally effective but safer. In addition, CDKN2A and RB1 pathways play significant role on the outcomes of the patients.

Durable Complete Remission of PD-L1 Positive NUT Carcinoma Treated With Concurrent Chemotherapy and Radiation.

INTRODUCTION: NUT carcinoma is an extremely rare disease and yet extremely aggressive with 2-year survival of only approximately 19% and median survival of 6 to 9 months. CASE PRESENTATION: We report here 2 successfully treated patients with durable complete remission (CR) after concurrent chemotherapy and radiation using 2 completely different chemotherapy regimens. One patient had extremely high tumor burden and obtained CR with ifosfamide and etoposide concurrently with radiation. One patient with low tumor burden obtained CR with carboplatin and paclitaxel concurrently with radiation. Interestingly, both patients had high PD-L1 expression in the tumor that may be associated with the favorable outcome. CONCLUSION: Our experiences with these 2 successfully treated patients offer insight for the management of NUT carcinoma.

Complete Regression of Rhabdomyosarcoma in an Adult Secondary to Postoperative Wound Infection Following Limb Salvage Surgery: A Case Report.

CASE PRESENTATION: A 33-year old man presented with a 25-cm lower extremity embryonal rhabdomyosarcoma with presumed extensive nodal metastasis on positron emission topography scan. Neoadjuvant chemotherapy and radiation provided minimal response. Following limb salvage resection and flap coverage, a prolonged postoperative infection occurred requiring intravenous antibiotics and wound care over 5 months. Given the infection, no postoperative radiation or chemotherapy was administered. Eight months following surgery, positron emission topography scan showed complete regression of local and nodal disease. The patient has remained in complete remission for more than 4 years. CONCLUSION: Postoperative wound infection leading to complete regression of embryonal rhabdomyosarcoma has not been reported. Stimulation of the innate and adaptive immune system through infectious elements is an area of ongoing immunotherapy research to improve sarcoma treatment outcomes.

Feasibility and Value of Establishing a Community-Based Virtual Multidisciplinary Sarcoma Case Conference.

PURPOSE: Management of soft tissue and bone sarcoma presents many challenges, both diagnostically and therapeutically, and requires multidisciplinary collaboration; however, such collaboration is often challenging to establish, especially in the community setting. We share our experiences of a virtual multidisciplinary sarcoma case conference (VMSCC). METHODS: We conducted retrospective review of the VMSCC data-initially via Webex, now Microsoft Teams-and the surveys of referring physicians to understand the feasibility and value of the VMSCC. RESULTS: The VMSCC was established in March 2013 in Kaiser Permanente Northern California with consistent participation of the Departments of Musculoskeletal Oncology (orthopedic oncology), Musculoskeletal Radiology, Pathology, Medical Oncology, Radiation Oncology, Nuclear Medicine, Surgical Oncology, and Genetics. Pediatric Oncology participated ad hoc when pediatric sarcoma cases were presented. Referrals were from multiple specialties and regions, including the Kaiser Permanente Mid-Atlantic and Hawaii regions. From March 2013 to December 2019, 1,585 cases were reviewed encompassing 36 histologic types. More than 300 cases were reviewed per year from 2017 to 2019. Survey results of referring physicians demonstrate that the VMSCC enhanced the confidence of treating physicians, and its recommendations frequently led to treatment changes. CONCLUSION: Establishing a valuable community-based VMSCC is feasible. VMSCC recommendations frequently led to treatment changes and improved the confidence of treating physicians.

Feasibility and Value of Establishing a Community-Based Virtual Multidisciplinary Sarcoma Case Conference.

PURPOSE: Management of soft tissue and bone sarcoma presents many challenges, both diagnostically and therapeutically, and requires multidisciplinary collaboration; however, such collaboration is often challenging to establish, especially in the community setting. We share our experiences of a virtual multidisciplinary sarcoma case conference (VMSCC). METHODS: We conducted retrospective review of the VMSCC data-initially via Webex, now Microsoft Teams-and the surveys of referring physicians to understand the feasibility and value of the VMSCC. RESULTS: The VMSCC was established in March 2013 in Kaiser Permanente Northern California with consistent participation of the Departments of Musculoskeletal Oncology (orthopedic oncology), Musculoskeletal Radiology, Pathology, Medical Oncology, Radiation Oncology, Nuclear Medicine, Surgical Oncology, and Genetics. Pediatric Oncology participated ad hoc when pediatric sarcoma cases were presented. Referrals were from multiple specialties and regions, including the Kaiser Permanente Mid-Atlantic and Hawaii regions. From March 2013 to December 2019, 1,585 cases were reviewed encompassing 36 histologic types. More than 300 cases were reviewed per year from 2017 to 2019. Survey results of referring physicians demonstrate that the VMSCC enhanced the confidence of treating physicians, and its recommendations frequently led to treatment changes. CONCLUSION: Establishing a valuable community-based VMSCC is feasible. VMSCC recommendations frequently led to treatment changes and improved the confidence of treating physicians.