Based on the demonstrated clinical activity of immune-checkpoint blockade (ICB) in advanced dedifferentiated liposarcoma (DDLPS) and undifferentiated pleomorphic sarcoma (UPS), we conducted a randomized, non-comparative phase 2 trial ( NCT03307616 ) of neoadjuvant nivolumab or nivolumab/ipilimumab in patients with resectable retroperitoneal DDLPS ( n = 17) and extremity/truncal UPS (+ concurrent nivolumab/radiation therapy; n = 10). The primary end point of pathologic response (percent hyalinization) was a median of 8.8% in DDLPS and 89% in UPS. Secondary end points were the changes in immune infiltrate, radiographic response, 12- and 24-month relapse-free survival and overall survival. Lower densities of regulatory T cells before treatment were associated with a major pathologic response (hyalinization > 30%). Tumor infiltration by B cells was increased following neoadjuvant treatment and was associated with overall survival in DDLPS. B cell infiltration was associated with higher densities of regulatory T cells before treatment, which was lost upon ICB treatment. Our data demonstrate that neoadjuvant ICB is associated with complex immune changes within the tumor microenvironment in DDLPS and UPS and that neoadjuvant ICB with concurrent radiotherapy has significant efficacy in UPS.

BackgroundRegional lymph node metastasis in extremity and trunk soft tissue sarcoma (ETSTS) is rare with no standardized management. We sought to determine management patterns for regional lymph node metastasis in ETSTS.MethodsA survey regarding the management of ETSTS lymph node metastasis was distributed to the membership of the Musculoskeletal Tumor Society (MSTS) and the Society of Surgical Oncology (SSO) in January 2022. The survey queried the type of training (surgical oncology, orthopedic oncology), details of their practice setting, and management decisions of hypothetical ETSTS scenarios that involved potential or confirmed lymph node metastasis.ResultsThe survey was distributed to 349 MSTS members (open rate of 63%, completion rate 21%) and 3026 SSO members (open rate of 55%, completion rate 4.7%) and was completed by 214 respondents, of whom 73 (34.1%) and 141 (65.9%) were orthopedic oncology and surgical oncology fellowship-trained, respectively. The majority of respondents practiced in an academic setting (n = 171, 79.9%) and treat >10 extremity sarcoma cases annually (n = 138, 62.2%). In scenarios with confirmed nodal disease for clear cell and epithelioid sarcoma, surgical oncologists were inclined to perform lymphadenectomy, while orthopedic oncologists were inclined to offer targeted lymph node excision with adjuvant radiation (p < 0.001). There was heterogeneity of responses regarding the management of nodal disease regardless of training background.ConclusionSelf-reported management of nodal disease in ETSTS was variable among respondent groups with differences and similarities based on training background. These data highlight the variability of practice for nodal disease management and the need for consensus-based guidelines.

Among the many sarcoma subtypes, high-grade tumors that have failed to differentiate or undergone dedifferentiation strongly correlate with metastatic potential and poor clinical outcomes. To examine the factors that regulate cell fate, lineage plasticity, and tumor grade, we focused on two common liposarcoma variants, dedifferentiated liposarcoma (DDLS) and well-differentiated liposarcomas (WDLS), that exist at both ends of the differentiation spectrum. Since tumor grading using histology is highly subjective due to widespread tumor heterogeneity, we hypothesized that an sc/snRNA-seq-based approach would be more accurate. To determine if candidate therapies modulate differentiation, we developed a quantitative metric of differentiation using scRNA-seq. The resulting mesenchymal tissue landscape (MTL) is akin to a Waddington landscape but optimized to distinguish DDLS from WDLS. After prospectively obtaining tumors from seven chemo-naïve patients, we performed scRNA-seq on three DDLS and five WDLS specimens, totaling 59,917 cells. Classical markers were used to identify cell types. Since no pre-existing liposarcoma training sets existed, malignant cells were identified by copy number variation (CNV) inferred from the scRNA-seq data. Overexpression of MDM2, CDK4, and HMGA2, known markers of LS, were positive in clusters classified by SingleR as fibroblasts, adipocytes, and myocyte - the mesenchymal subpopulation. We also inferred CNVs and found expected amplifications in 12q13-15 in the mesenchymal subpopulation. Next, we measured cell differentiation by CytoTRACE. A subcluster of malignant fibroblast-like cells positive for MDM2 and CDK4 was the most de-differentiated. Conversely, cells labeled as adipocytes and endothelial cells were the most differentiated cells. Mapping WDLS and DDLS onto the MTL demonstrated that WDLS had more mature cells than DDLS. Surprisingly, while the pathology-assigned diagnosis falls into just two categories, our approach identified a wide range of liposarcoma cells spanning the full spectrum of possible differentiation states. Though follow-on studies are needed, our data suggest that quantitative differentiation metrics can identify malignant cells in transit from a DDLS-to-WDLS state, or possibly the reverse, whereby cells undergo dedifferentiation. Both phenomena are suspected clinically, given the frequent co-existence of WDLS and DDLS in the same tumors, and the noted emergence of DDLS from WDLS diagnosed years earlier. Summarizing our key findings, we measured the degree of differentiation in liposarcoma cells as a precursor to ongoing studies aimed at understanding the molecular mechanisms that underpin LS plasticity and differentiation. Ultimately, we aim to identify the genes and pathways linked to cell fate and discover novel biologically targeted therapies capable of pushing DDLS toward a less aggressive, slower-growing state. Citation Format: Danh Truong, Hannah C. Beird, Chia-Chin Wu, Sandhya Krishnan, Davis Ingram, Alexander Lazar, Emily Keung, Christina Roland, Wantong Yao, Robert Benjamin, Neeta Somaiah, Barry W. Feig, Joseph A. Ludwig. Defining differentiation States in well-differentiated and de-differentiated liposarcoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6558.

Abstract Objective Well‐differentiated (WDLPS) and dedifferentiated liposarcoma (DDLPS) account for the majority of liposarcomas. Although gemcitabine‐docetaxel is used as second‐line treatment in soft tissue sarcomas, its efficacy in WDLPS/DDLPS is not established. This study retrospectively analyzed the efficacy of gemcitabine regimens in WDLPS/DDLPS. Methods All patients with WDLPS or DDLPS who received gemcitabine‐based chemotherapy at our institution between September 2002 and January 2021 were included. Response was evaluated by an independent radiologist using RECIST 1.1. The Kaplan–Meier method was used to estimate distributions of survival outcomes and log‐rank tests were used to compare survival outcomes between subgroups. Results Sixty‐five WDLPS/DDLPS patients were included. Seven patients (10.8%) received a gemcitabine‐based regimen more than once, totaling 72 treatments. The median age at the start of treatment was 66 years (range 32–80 years). Sixty‐five (90.3%) regimens were gemcitabine‐docetaxel, and 7 (9.7%) were gemcitabine alone. Majorities of treatments were for disease that was recurrent/metastatic (86.1%), was abdominal/retroperitoneal (83.3%), and had DDLPS components (88.9%), while 25.0% of treatments were for multifocal disease. The overall response rate was 9.7% (7/72). All responses were in patients with documented DDLPS. The median time to progression was 9.2 months (95% CI 5.3–12.3 months). The median overall survival from the start of therapy was 18.8 months (95% CI 13.1–32.4 months). Conclusion Gemcitabine‐docetaxel is an efficacious second‐line treatment for DDLPS. Though cross study comparisons are not advisable, response to gemcitabine‐docetaxel compares favorably to current standard options trabectedin and eribulin. This combination is a valid comparator arm for future second‐line trials in DDLPS.

Supplementary Figure 2 from Inhibition of Lipocalin 2 Impairs Breast Tumorigenesis and Metastasis

Multivariate parameters for all patients with OS from date of diagnosis, WART effect for CCS surgery patients with OS starting from surgery time, and statistics

Supplementary Figure Legends 1-5 from Inhibition of Lipocalin 2 Impairs Breast Tumorigenesis and Metastasis

Univariate parameters & statistics assessed for all patients

Overall Survival Probability of Bimodality vs. Trimodality Therapy

Background: Patients with unplanned excision (UPE) of trunk and extremity soft tissue sarcoma (STS) present a significant management challenge for sarcoma specialists. Oncologic re-resection has been considered standard practice after UPE with positive or uncertain margins. A strategy of active surveillance or "watch and wait" has been suggested as a safe alternative to routine re-excision. In this context, the current study sought to evaluate short-term outcomes and morbidity after re-resection to better understand the risks and benefits of this treatment strategy. Methods: A retrospective, single-institution study reviewed patients undergoing oncologic re-resection after UPE of an STS during a 5-year period (2015-2020), excluding those with evidence of gross residual disease. Short-term clinical outcomes were evaluated together with final pathologic findings. Results: The review identified 67 patients undergoing re-resection after UPE of an STS. Of these 67 patients, 45 (67%) were treated with a combination of external beam radiation therapy (EBRT) and surgery. Plastic surgery was involved for reconstruction in 49 cases (73%). The rate of wound complications after re-resection was 45 % (n = 30), with 15 % (n = 10) of the patients experiencing a major wound complication. Radiation therapy and plastic surgery involvement were independently associated with wound complications. Notably, 45 patients (67%) had no evidence of residual disease in the re-resection specimen, whereas 13 patients (19 %) had microscopic disease, and 9 patients (13%) had indeterminate pathology. Conclusion: Given the morbidity of re-resection and limited identification of residual disease, treatment plans and discussions with patients should outline the expected pathologic findings and morbidity of surgery.

LBA11501 Background: We conducted a randomized, phase II non-comparative trial evaluating the efficacy of neoadjuvant ICB [nivolumab or ipilimumab/nivolumab] in patients (pts) with surgically resectable retroperitoneal DDLPS or extremity/truncal UPS treated with concurrent neoadjuvant radiation therapy (XRT, UPS only). Methods: As of February 28 2022, all pts have a minimum follow-up of 2 years from the start of ICB treatment. Progression-free survival (PFS) and overall survival (OS) were calculated using Kaplan Meier method. The association of pathologic response (percent hyalinization and viable tumor at surgery) with PFS and OS was assessed using Cox univariate models. Comparison of survival curves was done by log-rank method. The intratumoral BCR repertoire was evaluated by bulk tumor RNA sequencing with TRUST4 algorithm, on biopsy specimens collected at baseline. Description of the intratumoral BCR repertoire included diversity by inverse Simpson index, and clonal distribution by Gini coefficient. High and low categories were defined by median values. Results: At a median follow-up of 31 months (interquartile range [IQR]=27-43) since start of ICB treatment, the median PFS was not reached (NR) in UPS (IQR=19-NR) and 18 months for DDLPS (IQR=8-NR), with 13 pts experiencing relapse (2 UPS, 11 DDLPS) and 2 pts who had progressive metastatic disease on treatment (1 UPS, 1 DDLPS). Five pts died of disease relapse (1 UPS, 4 DDLPS) and the median OS was NR. There was no association between percent hyalinization at surgery and PFS (Hazard Ratio [HR]=0.98, p=0.12) or OS (HR=0.99, p=0.60) nor between percent viable tumor at surgery and PFS (HR=1.00, p=0.62) or OS (HR=1.00, p=0.67). There was no association between RECIST response and PFS (p=0.67) or OS (p=0.67). The median BCR heavy chain (IgH) clonal counts detected at baseline was 2,536 per sample (IQR=82-7,680), and the median BCR light chain (IgL) clonal count was 8,870 per sample (IQR=306-30,214). Pts with higher intratumoral BCR clonality and diversity at baseline tended to have longer PFS (Table). High BCR IgH clonality was significantly associated with OS (p=0.02) with consistent trends in each histotype (DDLPS: p=0.06; UPS: p=0.25). Conclusions: Survival results demonstrate efficacy of ICB with XRT in UPS but there is a crucial need to define better predictive markers of survival after neoadjuvant therapy. Further characterization of the BCR repertoire is ongoing and will be presented at the meeting. Clinical trial information: NCT03307616. [Table: see text]

Background Lymph node metastases (LNMs) are rare in patients with soft tissue sarcoma (STS), and there is limited evidence to guide clinical management. We describe our experience with sentinel lymph node biopsy (SLNB) and lymphadenectomy in STS patients. Methods A single-center, retrospective review was performed for patients with STS treated with SLNB and/or lymphadenectomy from 1994 to 2018. Clinicopathologic characteristics, multimodality treatment, regional/distant recurrence-free survival (RFS), and overall survival (OS) were examined. Results Eighty-six patients underwent SLNB (n = 34) and/or lymphadenectomy (n = 60) for STS. The most frequent histologic subtypes were epithelioid, clear cell, and undifferentiated pleomorphic sarcoma. Eight of 34 (23.5%) patients had a positive SLNB with 5-year OS of 71.4% compared with 71.9% for those with a negative SLNB. Eight of the 26 SLN-negative patients (30.8%) eventually developed nodal recurrence (n = 2) and/or (n = 6) distant metastasis with an estimated 5-year OS of 50%. Of patients undergoing lymphadenectomy, estimated 5-year OS was 44.6% and median RFS was 12 months. Eight (13.3%) had distant disease at time of lymphadenectomy, 20 (33.3%) developed distant recurrence after lymphadenectomy, and 6 (10%) developed regional-only recurrence. Patients with regional-only recurrence after lymphadenectomy had an estimated 5-year OS of 66.7% compared with 29.1% for those who recurred distantly. Conclusions Patients with positive SLNB had similar survival to those with negative SLNB. Lymphadenectomy for isolated nodal disease is associated with poor RFS but reasonable 5-year OS when recurrence is regional-only. In STS, regional disease appears clinically distinct from distant metastatic disease and has better outcomes.

Background Intratumoral B-cells are associated with improved survival with ICB in sarcomas.1 We investigated the dynamics of intratumoral and peripheral BCR repertoires and their association with survival in dedifferentiated liposarcoma (DDLPS, n=17) and undifferentiated pleomorphic sarcoma (UPS, n=10) patients treated in a neoadjuvant ICB trial of nivolumab +/- ipilimumab.2-4 Methods Tumor and peripheral blood mononuclear cells (PBMCs) were collected at baseline and surgery. Intratumoral and peripheral BCR heavy (IgH) and light (IgL) chain repertoires were evaluated using bulk RNA sequencing and the TRUST4 algorithm.5 IgH and IgL repertoire diversity and clonality were assessed by inverse Simpson and Gini index, respectively. Comparisons of continuous variables were done using Wilcoxon Rank-Sum test. High and low categories were defined by median values. Comparisons of progression-free survival (PFS) and overall survival (OS) curves were performed by log-rank method. Correlations were assessed using Spearman's correlation. Results Tumor transcriptomic data was available for 23 and 20 patients at baseline and surgery, respectively. PBMC transcriptomic data was available for 19 and 23 patients at baseline and surgery, respectively. BCR repertoire diversity increased with ICB, which was significant only in PBMCs (tumor: IgH p=0.077, IgL p=0.11; PBMC: IgH p=0.0065, IgL p=0.029; figures 1 and 2). Neither intratumoral nor peripheral BCR repertoire clonality was impacted by ICB treatment (figures 3 and 4). At baseline, patients with higher IgH BCR diversity had longer PFS (intratumoral: not reached [NR] vs 19 months, p=0.15; peripheral: NR vs 37 months, p=0.25). However, at surgery, patients with higher intratumoral IgH BCR diversity had shorter PFS (17 vs NR months, p=0.024), while peripheral BCR diversity was not associated with PFS (p=0.98). At baseline, patients with higher intratumoral IgH BCR clonality had longer PFS (p=0.19) and significantly longer OS (p=0.022) while neither intratumoral nor peripheral BCR clonality at surgery was associated with survival. Conclusions ICB is associated with increases in intratumoral and peripheral BCR diversity but not with changes in clonality. Overall, neither the intratumoral IgL nor peripheral IgH and IgL BCR repertoires were associated with survival. Greater diversity of the intratumoral IgH repertoire was a favorable prognostic factor at baseline but a negative one after ICB. These findings warrant future investigations. Acknowledgements This study was supported by Bristol Myers Squibb. EFN received support from Fondation pour la Recherche Medicale and Fondation Nuovo-Soldati. CLR received support from American College of Surgeons and Society of Surgical Oncology. EZK received support from NCI Early Surgeon Scientist Program. Trial Registration NCT03307616 References Petitprez F, de Reynies A, Keung EZ, Chen TW, Sun CM, Calderaro J, et al. B cells are associated with survival and immunotherapy response in sarcoma. Nature. 2020;577(7791):556-60. Keung EZ-Y, Nassif EF, Lin HY, Lazar AJ, Torres KE, Wang W-L, et al. Randomized phase II study of neoadjuvant checkpoint blockade for surgically resectable undifferentiated pleomorphic sarcoma (UPS) and dedifferentiated liposarcoma (DDLPS): Survival results after 2 years of follow-up and intratumoral B-cell receptor (BCR) correlates. Journal of Clinical Oncology. 2022;40(17_suppl):LBA11501-LBA. Roland CL, Keung EZ-Y, Lazar AJ, Torres KE, Wang W-L, Guadagnolo A, et al. Preliminary results of a phase II study of neoadjuvant checkpoint blockade for surgically resectable undifferentiated pleomorphic sarcoma (UPS) and dedifferentiated liposarcoma (DDLPS). Journal of Clinical Oncology. 2020;38(15_suppl):11505. Keung E, Nassif E, Lin H, Lazar A, Wang W-L, Parra E, et al. 379 Immune infiltrates are associated with clinical outcomes in patients with resectable soft tissue sarcoma (STS) treated with neoadjuvant immune checkpoint blockade (ICB). Journal for ImmunoTherapy of Cancer. 2021;9(Suppl 2):A410–A2. Hu X, Zhang J, Wang J, Fu J, Li T, Zheng X, et al. Landscape of B cell immunity and related immune evasion in human cancers. Nat Genet. 2019;51(3):560–7. Ethics Approval This study was approved by MD Anderson Cancer Center Institutional Review Board. IRB approval 2017-0143. All participants gave written informed consent.

Background: We evaluated the activity of neoadjuvant ICB in localized resectable DDLPS (n=17) and undifferentiated pleomorphic sarcomas (UPS; n=10). DDLPS and UPS patients were randomized to neoadjuvant nivolumab or ipilimumab+nivolumab, with UPS patients receiving concurrent radiotherapy. We assessed genomic markers of early relapse (progression before surgery or relapse within 52 weeks following surgery) using longitudinally acquired tumor samples. Methods: RNA sequencing (RNAseq) and whole genome sequencing (WGS) were performed on longitudinally acquired samples (baseline biopsies and surgical specimens). Differential gene expression between any two groups of patients (i.e., non-early relapse [non-relapsers] vs early relapse [relapsers]) were selected (fold change>1.5 and p value<0.05). Gene set enrichment analyses (GSEA) of KEGG pathways were performed and a network-based approach used to identify genes/pathways associated with MHC-I. Results: At a median follow-up of 23 months, 12 patients (9 DDLPS, 3 UPS) relapsed, including 7 early relapses (relapsers: 5 DDLPS, 2 UPS). The median relapse-free survival was 22 months in DDLPS patients (6 months in relapsers; not reached [NR] in non-relapsers) and NR in UPS patients. At baseline, the most differentially upregulated pathways in non-relapsers compared to relapsers were “graft versus host disease” (GSEA Normalized Enrichment Score[NES]=2.25; False Discovery Rate[FDR] q= 0.009), “natural killer cell mediated cytotoxicity” (NES=2.17; FDR q=0.009), “antigen processing and presentation” (NES=2.16; FDR q=0.009), “allograft rejection” (NES=1.99; FDR q=0.019) and “B-cell receptor signaling pathway” (NES=1.87; FDR q=0.018). In DDLPS patients, the antigen presentation and processing pathway was the most upregulated pathway in non-relapsers compared to relapsers (NES=2.01; FDR q=0.025) while it was not significantly upregulated in UPS (NES=1.15; FDR q=0.62). When looking at pathways longitudinally, the antigen presentation and processing pathway was significantly upregulated at surgery compared to baseline in DDLPS. As antigen presentation and processing was significantly upregulated in DDLPS patients and associated with relapse, we looked for expressed neoantigens that may be processed and presented. Using WGS, we detected 5712 rearrangements at baseline in DDLPS, of which 230 were found in more than one tumor specimen. We also sought to identify genes associated with MHC-I. We selected genes upregulated during ICB comparing baseline to surgical specimens in DDLPS relapsers and looked at the top 10% of genes associated with MHC-I in order to identify potential therapeutic targets for combination. We identified 41 genes upregulated during ICB and associated with MHC-I in relapsers, for which up to 275 inhibitory compounds were found in drug databases. Conclusion: Antigen presentation and processing is a major driver of response to immunotherapy. Future efforts should focus on identifying which antigens are presented to find synergizing compounds in order to increase the clinical benefit of ICB. Citation Format: Elise F. Nassif, Chia-Chin Wu, Kadir Akdemir, Russell G. Witt, Raymond Traweek, Brandon Cope, Prapassorn Thirasastr, Taylor Tate, Grace Mathew, Shadarra Crosby, Randy Chu, Mohammad Mohammad, Kenna Shaw, Ingram Davis, Khalida Wani, Alexander J. Lazar, Wei-Lien Wang, Sheila Duncan, Ashleigh B. Guadagnolo, Andrew J. Bishop, Valerae Lewis, Justin E. Bird, Keila E. Torres, Kelly K. Hunt, Barry W. Feig, Christopher P. Scally, Ravin Ratan, Shreyaskumar Patel, Robert S. Benjamin, Robert Satcher, Kevin McBride, Wolf H. Fridman, Ignacio Wistuba, Andrew Futreal, Jennifer A. Wargo, Neeta Somaiah, Christina L. Roland, Emily Z. Keung. Antigen presentation and processing pathway is associated with early relapse after neoadjuvant immune checkpoint blockade (ICB) in dedifferentiated liposarcomas (DDLPS) [abstract]. In: Proceedings of the AACR Special Conference: Sarcomas; 2022 May 9-12; Montreal, QC, Canada. Philadelphia (PA): AACR; Clin Cancer Res 2022;28(18_Suppl):Abstract nr PR002.

EORTC-62092 (STRASS) was a phase 3, randomized study that compared surgery alone versus surgery plus neoadjuvant radiotherapy (RT) for retroperitoneal sarcomas. RT was not associated with improved abdominal recurrence-free survival, the primary outcome measure, although on subanalysis, there may have been benefit for well-differentiated (WD) liposarcoma. This study investigated the real-world use and outcomes of RT (neoadjuvant and adjuvant) for the management of retroperitoneal liposarcoma. We queried the National Cancer Database (NCDB) (2004–2017) for patients with nonmetastatic, primary retroperitoneal liposarcoma treated with resection with or without RT (n = 3911). Patients were stratified by treatment type and histology [WD (n = 2252), dedifferentiated (DD) (n = 1659)]. Propensity score (PS) matching was used before comparison of treatment groups. Overall survival (OS) was the primary outcome measure. Median follow-up time was 4.1 years, and median OS was 10.7 years. There was no association between RT and OS for either WDLPS or DDLPS cohorts. We performed a subgroup analysis of neoadjuvant RT only, similar to STRASS. For WDLPS after PS matching (n = 208), neoadjuvant RT was not associated with OS (hazard ratio [HR] 1.01, p = 0.0523) but was associated with longer postoperative hospital stay (p = 0.012). For DDLPS after PS matching (n = 290), neoadjuvant RT was not associated with OS (HR 1.02, p = 0.889). For both WD-LPS and DD-LPS, utilization of neoadjuvant RT was associated with treatment at high-volume (≥ 10 cases/year) and academic/network facilities. For primary retroperitoneal liposarcoma treated with surgical resection, radiotherapy was not associated with an overall survival benefit in this propensity-matched, adjusted analysis of the NCDB.

BACKGROUND:Sarculator is an online validated nomogram that predicts overall survival of patients with resected, primary extremity sarcomas. However, its ability to accurately predict outcomes in US patients with sarcoma is unknown. PATIENTS AND METHODS:Patients from the National Cancer Data Base (NCDB) (2006-2016) with resected stage I-III primary extremity or trunk sarcoma were included. Predicted overall survival (pOS) was calculated using the Sarculator algorithm, which includes patient age, tumor size (cm), grade (1-3), and histology, and compared with actual overall survival (aOS). Harrell's C-index was calculated to determine the discriminatory ability of Sarculator (0.7 = good, 0.8 = strong, 1.0 = perfect model), and calibration plots were created. RESULTS:In total, 9738 patients were included. Five-year pOS was 73.7% compared with aOS of 68.9%. The C-index for the entire cohort was 0.726. By stage, the C-index was 0.730 for stage I, 0.708 for stage II, and 0.679 for stage III. By histology, C-indices were highest for leiomyosarcoma (0.745), myxofibrosarcoma (0.722), and other histologies (0.721). By sociodemographic variables, Sarculator performed better for patients < 50 years (C-index 0.722), of other/unknown race (C-index 0.781), with private insurance (C-index 0.715), treated at a center other than a community cancer programs (C-index > 0.7), and with no comorbidities (C-index 0.716). Outcomes by zip code educational attainment and income were not markedly different (all C-indices > 0.7). CONCLUSIONS:Sarculator is overall a good predictor of aOS and useful tool for clinicians to aid in survival prognostication. However, clinicians should be aware of populations for whom Sarculator's predictions may be less accurate. Future work could focus on enhancing the Sarculator algorithm specifically for US patients by including demographic variables.

Background: We designed a prospective feasibility study to assess the 5x-multiplier (5x) calculation (eg, 3 pills in last 24 hours x 5 = 15) to standardize discharge opioid prescriptions compared to usual care. Methods: Faculty-based surgical teams volunteered for either 5x or usual care arms. Patients undergoing inpatient (>= 48 hours) surgery and discharged by surgical teams were included. The primary end point was discharge oral morphine equivalents. Secondary end points were opioid-free discharges and 30-day refill rates. Results: Median last 24-hour oral morphine equivalents was similar between arms (7.5 mg 5x vs 10 mg usual care, P = .830). Median discharge oral morphine equivalents were less in the 5x arm (50 mg 5x vs 75 mg usual care, P < .001). Opioid-free discharges included 33.5% 5x vs 18.0% usual care arm patients (P < .001). Thirty-day refill rates were similar (153% 5x vs 16.5% usual care, P = .742). Conclusion: The 5x-multiplier was associated with reduced opioid prescriptions without increased refills and can be feasibly implemented across a diverse surgical practice. (C) 2022 The Author(s). Published by Elsevier Inc.

11544 Background: In SARC028, patients with undifferentiated pleomorphic sarcoma (UPS) had a 40% overall response rate to pembrolizumab. Based on this, we conducted a randomized, phase II, non-comparative trial of combination nivolumab (nivo/RT) and ipilimumab (ipi/nivo/RT) and demonstrated an 89% major pathologic response. Here, we report the health-related quality of life (HRQoL) metrics. Methods: In this study (NCT03307616), patients with resectable UPS were randomized (1:1) to receive one dose of nivo (3mg/kg) or one dose of combination nivo (3 mg/kg) and ipi (1 mg/kg), followed by combination of nivo (3 doses, 3mg/kg every 2 weeks) plus 50 Gy in 25 fractions (both arms). HRQoL was assessed using the MD Anderson Symptom Inventory (MDASI), European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLC) Core 30, and the Functional Assessment of Cancer Therapy – General (FACT-G) questionnaires. Questionnaire completion rates were calculated using the number of patients with at least one baseline and post-baseline assessment. Analyses included mean change from baseline scores to week 11 (preoperative) and week 54 (postoperative). Results: Ten patients were randomized from October 2017 to February 2020. HRQoL were collected at baseline (n = 10) and at week 11 for five (83%) nivo/RT and three (60%) ipi/nivo/RT patients. Three (60%) nivo/RT and three (100%) ipi/nivo/RT patients had week 54 assessments. MDASI scores indicative of symptom severity and interference of daily life both decreased for patients undergoing ipi/nivo/RT (0.8→0.67 and 0.9→0.46, respectively) while both increased in the nivo/RT group (1.6→2.22 and 1.9→3.33, respectively). Both arms had similar increases at 54 weeks. Patients undergoing ipi/nivo/RT experienced a greater decline in EORTC-QLC global health status at 54 weeks than those undergoing single agent therapy (-22.92 vs -8.33). The mean change in total FACT-G score did not differ between the two arms at 11 weeks (-4.0 vs -4.5), however, there was a significant decline for patients undergoing ipi/nivo/RT at 54 weeks (-20.3 vs -5.7). Conclusions: For patients with resectable UPS, combination immune checkpoint blockade with ipi/nivo/RT is associated with an improvement in short term HRQoL compared to single-agent nivo/RT. This finding warrants further study with more patients, controlling for baseline symptom scores. Combination therapy was associated with a slower recovery to baseline function, with ongoing decline in HRQoL at 54 weeks post treatment. Our study demonstrates the feasibility of collecting HRQoL metrics, which can be key factors in guiding patient management decisions. Clinical trial information: NCT03307616.

Palbociclib has been evaluated in early phase trials for well‐differentiated liposarcoma (WDLPS) and dedifferentiated liposarcoma (DDLPS) patients, with reported median progression‐free survival (PFS) of 18 weeks. Here, we report on real‐world use and surgical outcomes associated with palbociclib treatment. We retrospectively reviewed 61 consecutive patients with retroperitoneal WDLPS (n = 14) or DDLPS (n = 47) treated with palbociclib monotherapy between 1 March 2016 and 28 February 2021 at The University of Texas MD Anderson Cancer Center. At palbociclib initiation, median age was 64 (interquartile range [IQR] 56‐72). In WDLPS and DDLPS cohorts, the median number of prior systemic treatments was 0 (IQR 0‐0) and 2 (IQR 0‐4), respectively. Median number of prior surgeries was 2 (WDLPS IQR 1‐2.75) and 2 (DDLPS IQR 1‐3). Median PFS was 9.2 (WDLPS IQR 3.9‐21.9) and 2.6 months (DDLPS IQR 2.0‐6.1), with median time on treatment of 7.4 months (WDLPS IQR 3.5‐14.2) and 2.7 months (DDLPS IQR 2.0‐5.7). Twelve patients ultimately underwent surgical resection. Resections were macroscopically complete (R0/R1) in half (n = 6/12), among whom only one patient experienced relapse after resection (median follow‐up 7.5 months). All patients who underwent macroscopically incomplete resections progressed after surgery with median time to progression of 3.3 months (IQR 2.3‐4.4). Surgery after palbociclib treatment was not associated with improved overall survival. Efficacy of palbociclib monotherapy for patients with advanced WDLPS and DDLPS is disappointing. While palbociclib may have been used to delay surgery, there was no clear benefit from treatment and few patients achieved prolonged tumor control.