Outcomes of Late-Line Systemic Treatment in GIST: Does Sequence Matter?

Ripretinib and avapritinib have demonstrated activity in the late-line treatment of gastrointestinal stomal tumors (GISTs). We investigated whether patients previously treated with ripretinib benefit from avapritinib, and vice versa. Patients diagnosed with metastatic/unresectable GIST and treated with both drugs at two institutions in 2000-2021 were included. Patients were grouped by drug sequence: ripretinib-avapritinib (RA) or avapritinib-ripretinib (AR). Radiographic response was evaluated using RECIST 1.1. Kaplan-Meier and log-rank tests were used to compare time-to-progression (TTP) and overall survival (OS). Thirty-four patients (17 per group) were identified, with a median age of 48 years. The most common primary site was the small bowel (17/34, 50%), followed by the stomach (10/34, 29.4%). Baseline characteristics and tumor mutations were not significantly different between groups. Response rates (RRs) for ripretinib were 18% for RA and 12% for AR; RRs for avapritinib were 12% for AR and 18% for RA. Median TTPs for ripretinib were 3.65 months (95%CI 2-5.95) for RA and 4.73 months (1.87-15.84) for AR. Median TTPs for avapritinib were 5.39 months (2.86-18.99) for AR and 4.11 months (1.91-11.4) for RA. Median OS rates following RA or AR initiation were 29.63 (95%CI 13.8-50.53) and 33.7 (20.03-50.57) months, respectively. Both ripretinib and avapritinib were efficacious in the late-line treatment of GIST, with no evidence that efficacy depended on sequencing.

Impact of Biomarker-Matched Therapies on Outcomes in Patients with Sarcoma Enrolled in Early-Phase Clinical Trials (SAMBA 101).

PURPOSE: Developing new therapeutics for any of the more than 100 sarcoma subtypes presents a challenge. After progression from standard therapies, patients with sarcoma may be referred for enrollment in early-phase trials. This study aimed to investigate whether enrollment in biomarker-matched early-phase clinical trials leads to better outcomes for patients with advanced sarcoma. EXPERIMENTAL DESIGN: In this retrospective analysis, investigational treatment characteristics and longitudinal survival outcomes were analyzed in patients with biopsy-confirmed sarcoma enrolled in early-phase trials at MD Anderson Cancer Center from May 2006 to July 2021. RESULTS: Five hundred eighty-seven patients were included [405 soft tissue, 122 bone, 60 gastrointestinal stromal tumor (GIST); median of three prior lines of therapy]. Most common subtypes were leiomyosarcoma (17.2%), liposarcoma (14.0%), and GIST (10.2%). Molecular testing was available for 511 patients (87.1%); 221 patients (37.6%) were treated in matched trials. Overall response rate was 13.1% matched compared with 4.9% in unmatched (P < 0.001); the clinical benefit rate at 6 months was 43.9% vs. 19.9% (P < 0.001). Progression-free survival was longer for patients in matched trials (median, 5.5 vs. 2.4 months; P < 0.001), and overall survival was also superior for patients in matched trials (median, 21.5 vs. 12.3 months; P < 0.001). The benefit of enrollment in matched trials was maintained when patients with GIST were excluded from the analysis. CONCLUSIONS: Enrollment in biomarker-matched early-phase trials is associated with improved outcomes in heavily pretreated patients with metastatic sarcoma. Molecular testing of tumors from patients with advanced sarcoma and enrollment in matched trials is a reasonable therapeutic strategy.

Examining Stripes on a Herd of Zebras: Impact of Genomic Matching for Ultrarare Sarcomas in Phase 1 Clinical Trials (SAMBA 102).

PURPOSE: Recently, the Connective Tissue Oncology Society published consensus guidelines for recognizing ultrarare sarcomas (URS), defined as sarcomas with an incidence ≤1 per 1,000,000. We assessed the outcomes of 56 patients with soft tissue, and 21 with bone sarcomas, enrolled in Phase 1 trials. EXPERIMENTAL DESIGN: In this Sarcoma-Matched Biomarker Analysis (SAMBA-102 study), we reviewed records from patients on Phase 1 trials at the University of Texas MD Anderson Cancer Center between January 2013 and June 2021. RESULTS: Among 587 sarcomas, 106 (18.1%) were classified as URS. Fifty (47%) were male, and the median age was 44.3 years (range, 19-82). The most common subtypes were alveolar soft part sarcoma (ASPS), chordoma, dedifferentiated chondrosarcoma, and sclerosing epithelioid fibrosarcoma. Compared with common sarcomas, median OS was similar 16.1 months [95% confidence interval (CI), 13.6-17.5] versus 16.1 (95% CI, 8.2-24.0) in URS (P = 0.359). Objective response to treatment was higher in URS 13.2% (n = 14/106) compared with common sarcomas 6.9% (n = 33/481; P = 0.029). Median OS for those treated on matched trials was 27.3 months (95% CI, 1.9-52.7) compared with 13.4 months (95% CI, 6.3-20.6) for those not treated on matched trials (P = 0.291). Eight of 33 (24%) molecularly matched treatments resulted in an objective response, whereas 6 of 73 unmatched treatments (8.2%) resulted in an objective response (P = 0.024). Clinical benefit rate was 36.4% (12/33) in matched trials versus 26.0% (19/73) in unmatched trials (P = 0.279). CONCLUSIONS: The results demonstrate the benefit of genomic selection in Phase 1 trials to help identify molecular subsets likely to benefit from targeted therapy.

Retrospective evaluation of the role of gemcitabine-docetaxel in well-differentiated and dedifferentiated liposarcoma.

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.

Hypofractionated, 3-week, preoperative radiotherapy for patients with soft tissue sarcomas (HYPORT-STS): a single-centre, open-label, single-arm, phase 2 trial.

BACKGROUND: The standard preoperative radiotherapy regimen of 50 Gy delivered in 25 fractions for 5 weeks for soft tissue sarcomas results in excellent local control, with major wound complications occurring in approximately 35% of patients. We aimed to investigate the safety of a moderately hypofractionated, shorter regimen of radiotherapy, which could be more convenient for patients. METHODS: This single-centre, open-label, single-arm, phase 2 trial (HYPORT-STS) was done at a single tertiary cancer care centre (MD Anderson Cancer Center, Houston, TX, USA). We administered preoperative radiotherapy to a dose of 42·75 Gy in 15 fractions of 2·85 Gy/day for 3 weeks (five fractions per week) to adults (aged ≥18 years) with non-metastatic soft tissue sarcomas of the extremities or superficial trunk and an Eastern Cooperative Oncology Group performance status of 0-3. The primary endpoint was a major wound complication occurring within 120 days of surgery. Major wound complications were defined as those requiring a secondary operation, or operations, under general or regional anaesthesia for wound treatment; readmission to the hospital for wound care; invasive procedures for wound care; deep wound packing to an area of wound measuring at least 2 cm in length; prolonged dressing changes; repeat surgery for revision of a split thickness skin graft; or wet dressings for longer than 4 weeks. We analysed our primary outcome and safety in all patients who enrolled. We monitored safety using a Bayesian, one-arm, time-to-event stopping rule simulator comparing the rate of major wound complications at 120 days post-surgery among study participants with the historical rate of 35%. This trial is registered with ClinicalTrials.gov, NCT03819985, recruitment is complete, and follow-up continues. FINDINGS: Between Dec 18, 2018, and Jan 6, 2021, we assessed 157 patients for eligibility, of whom 120 were enrolled and received hypofractionated preoperative radiotherapy. At no time did the stopping rule computation indicate that the trial should be stopped early for lack of safety. Median postoperative follow-up was 24 months (IQR 17-30). Of 120 patients, 37 (31%, 95% CI 24-40) developed a major wound complication at a median time of 37 days (IQR 25-59) after surgery. No patient had acute radiation toxicity (during radiotherapy or within 4 weeks of the radiotherapy end date) of grade 3 or worse (Common Terminology Criteria for Adverse Events [CTCAE] version 4.0) or an on-treatment serious adverse event. Four (3%) of 115 patients had late radiation toxicity (≥6 months post-surgery) of at least grade 3 (CTCAE or Radiation Therapy Oncology Group/European Organisation for Research and Treatment of Cancer Late Radiation Morbidity Scoring Scheme): femur fractures (n=2), lymphoedema (n=1), and skin ulceration (n=1). There were no treatment-related deaths. INTERPRETATION: Moderately hypofractionated preoperative radiotherapy delivered to patients with soft tissue sarcomas was safe and could therefore be a more convenient alternative to conventionally fractionated radiotherapy. Patients can be counselled about these results and potentially offered this regimen, particularly if it facilitates care at a sarcoma specialty centre. Results on long-term oncological, late toxicity, and functional outcomes are awaited. FUNDING: The National Cancer Institute.

Retrospective observational studies in ultra-rare sarcomas: A consensus paper from the Connective Tissue Oncology Society (CTOS) community of experts on the minimum requirements for the evaluation of activity of systemic treatments.

BACKGROUND: In ultra-rare sarcomas (URS) the conduction of prospective, randomized trials is challenging. Data from retrospective observational studies (ROS) may represent the best evidence available. ROS implicit limitations led to poor acceptance by the scientific community and regulatory authorities. In this context, an expert panel from the Connective Tissue Oncology Society (CTOS), agreed on the need to establish a set of minimum requirements for conducting high-quality ROS on the activity of systemic therapies in URS. METHODS: Representatives from > 25 worldwide sarcoma reference centres met in November 2020 and identified a list of topics summarizing the main issues encountered in ROS on URS. An online survey on these topics was distributed to the panel; results were summarized by descriptive statistics and discussed during a second meeting (November 2021). RESULTS: Topics identified by the panel included the use of ROS results as external control data, the criteria for contributing centers selection, modalities for ensuring a correct pathological diagnosis and radiologic assessment, consistency of surveillance policies across centers, study end-points, risk of data duplication, results publication. Based on the answers to the survey (55 of 62 invited experts) and discussion the panel agreed on 18 statements summarizing principles of recommended practice. CONCLUSIONS: These recommendations will be disseminated by CTOS across the sarcoma community and incorporated in future ROS on URS, to maximize their quality and favor their use as control data when results from prospective studies are unavailable. These recommendations could help the optimal conduction of ROS also in other rare tumors.

Clinical activity of checkpoint inhibitors in angiosarcoma: A retrospective cohort study.

BACKGROUND: Systemic treatments for angiosarcoma remains an area of unmet clinical need. The authors conducted this retrospective study to assess the clinical activity of checkpoint inhibitors in patients with angiosarcoma. The primary objective was to assess the objective response rate, and the secondary objective was to assess the progression-free and overall survival durations and disease control rate. METHODS: Patient data were obtained using The University of Texas MD Anderson Cancer Center Tumor Registry database. The final study population was refined to only include patients who had undergone pembrolizumab monotherapy. The objective response rate was evaluated using RECIST/irRECIST version 1.1. Progression-free survival and overall survival were defined as the time from the initiation of immunotherapy to disease progression or recurrence, death, or last follow-up and to death or last follow-up, respectively. RESULTS: The final cohort comprised 25 patients. Most patients had metastatic disease (72%) and had undergone at least two lines of systemic therapy (80%) before starting pembrolizumab. The objective response rate was 18%, whereas the disease control rate was 59%. The median progression-free survival duration was 6.2 months and was not significantly different between the cutaneous (4.7 months) and visceral angiosarcoma (6.2 months) groups (p = .42). The median overall survival duration was 72.6 months. Toxicities were recorded for eight patients, with fatigue, anemia, constipation, and rash being the most common. CONCLUSIONS: Pembrolizumab shows durable clinical activity in angiosarcoma. These findings suggest that checkpoint inhibition as monotherapy or combination therapy is likely to have a high probability of success.© 2022 American Cancer Society. LAY SUMMARY: This is the largest retrospective study to assess the clinical activity of checkpoint inhibitor monotherapy in angiosarcomas. The study includes an adequate number of patients with visceral angiosarcoma that enabled to obtain meaningful clinical insights that were previously unavailable. Our findings indicate an improvement in progression-free survival with pembrolizumab that is comparable to other active agents in angiosarcoma. Pembrolizumab monotherapy in angiosarcomas also has a favorable tolerability profile. Our findings emphasize the need for prospective studies to evaluate the activity of pembrolizumab monotherapy and combination therapy.

There is more to soft tissue sarcomas than just grade and size.

LAY SUMMARY: Sarculator is better at predicting patients with sarcoma at the highest risk of death than current staging systems and should be used to determine appropriate patients for future studies.

Doxorubicin-Dexrazoxane from Day 1 for Soft-tissue Sarcomas: The Road to Cardioprotection.

Doxorubicin cardiac toxicity is widely misunderstood, largely preventable, and starts with the first dose. This article reviews the history of doxorubicin cardiac toxicity and strategies for minimizing it. Dexrazoxane cardioprotection can safely be initiated on day 1 without compromising antitumor activity, allowing doxorubicin administration beyond the reported maximum lifetime dose.See related articles by Van Tine et al., p. 3854 and Jones et al., p. 3861.

Synovial Sarcoma of the Hand and Foot: An Institutional Review.

OBJECTIVES: Synovial sarcomas (SS) arising in distal extremities are rare and have been studied using mostly case reports and small series. We aimed to evaluate clinical presentation and survival outcomes for patients with hand or foot SS. MATERIALS AND METHODS: We conducted a retrospective review of 84 patients diagnosed with primary hand (n=20) and foot (n=64) SS between 1979 and 2019. Progression-free survival (PFS), overall survival (OS), local recurrence-free survival and metastasis-free survival were estimated using the Kaplan-Meier method and log-rank test. Cox-proportional hazards regression was used to estimate the hazard ratios. RESULTS: Of 84 patients, 63 (75%) presented with localized disease with 36 years median age at diagnosis (range: 4 to 76) and 21 (25%) with metastasis with 30 years median age at diagnosis (range: 15 to 64). Among patients presenting with localized disease, (1) 5 years-PFS, OS, local recurrence-free survival, and metastasis-free survival rates were 82%, 88%, 100%, and 86%, respectively. (2) Tumor size <3.0 cm corresponded to 95% 5 years-PFS (vs. 84% for 3.0 to 4.9 cm, 53% for ≥5.0 cm; P=0.007) and 100% 5 years-OS (vs. 77% for ≥3.0 cm; P=0.04). (3) Patients with ≥5.0 cm (vs. <3.0 cm) tumor size had 7.99 (95% confidence interval: 1.68, 37.91) times higher hazard of progression. Remarkably, patients presenting with metastasis had 50% 5 years-OS rate. Also, younger age (15 to 39 vs. 40 y and above) predicted better OS among patients presenting with localized disease (P=0.04) and with metastasis (P=0.03). CONCLUSIONS: Survival outcomes are favorable for younger patients with <3.0 cm hand or foot SS. Local control is excellent, but we observed larger tumor size to be associated with poorer outcomes. Therefore, we recommend consideration of systemic therapy for patients with ≥3.0 cm hand or foot SS.

Systemic therapies in advanced epithelioid haemangioendothelioma: A retrospective international case series from the World Sarcoma Network and a review of literature.

BACKGROUND: This observational, retrospective effort across Europe, US, Australia, and Asia aimed to assess the activity of systemic therapies in EHE, an ultra-rare sarcoma, marked by WWTR1-CAMTA1 or YAP1-TFE3 fusions. METHODS: Twenty sarcoma reference centres contributed data. Patients with advanced EHE diagnosed from 2000 onwards and treated with systemic therapies, were selected. Local pathologic review and molecular confirmation were required. Radiological response was retrospectively assessed by local investigators according to RECIST. Progression free survival (PFS) and overall survival (OS) were estimated by Kaplan-Meier method. RESULTS: Overall, 73 patients were included; 21 had more than one treatment. Thirty-three patients received anthracyclines regimens, achieving 1 (3%) partial response (PR), 25 (76%) stable disease (SD), 7 (21%) progressive disease (PD). The median (m-) PFS and m-OS were 5.5 and 14.3 months respectively. Eleven patients received paclitaxel, achieving 1 (9%) PR, 6 (55%) SD, 4 (36%) PD. The m-PFS and m-OS were 2.9 and 18.6 months, respectively. Twelve patients received pazopanib, achieving 3 (25%) SD, 9 (75%) PD. The m-PFS and m-OS were.2.9 and 8.5 months, respectively. Fifteen patients received INF-α 2b, achieving 1 (7%) PR, 11 (73%) SD, 3 (20%) PD. The m-PFS and m-OS were 8.9 months and 64.3, respectively. Among 27 patients treated with other regimens, 1 PR (ifosfamide) and 9 SD (5 gemcitabine +docetaxel, 2 oral cyclophosphamide, 2 others) were reported. CONCLUSION: Systemic therapies available for advanced sarcomas have limited activity in EHE. The identification of new active compounds, especially for rapidly progressive cases, is acutely needed.

Outcomes of systemic therapy in metastatic phyllodes tumor of the breast.

PURPOSE: Metastatic phyllodes tumors of the breast (MPT) are rare breast neoplasms, limiting development of standardized treatment approaches. We sought to characterize the largest group of MPT thus far reported, evaluating systemic therapy outcomes. METHODS: Adult patients diagnosed with MPT between 1993 and 2015 and followed at MD Anderson Cancer Center were selected for retrospective chart review. Systemic therapy was sorted into: adriamycin/ifosfamide (AI), other anthracycline regimens, other ifosfamide regimens, gemcitabine-based regimens, and other. Given one patient may have received more than one regimen, we assumed that the effects of each regimen were independent from previous therapy. Median overall survival (OS) and progression-free survival (PFS) were estimated by the Kaplan-Meier method. Log-rank test was performed to evaluate the difference in OS between patient characteristics groups, and the differences in PFS between the five chemotherapy regimens. RESULTS: We identified 50 MPT patients, with 31 patients receiving 61 systemic regimens. Median OS was 10.7 months (95% CI: 8.67, 16.5). AI had a PFS of 9.10 months (95% CI: 5.03, 14.2), other ifosfamide regimens had a PFS of 5.10 months (95% CI: 0.67, 12.1), other anthracycline regimens had a PFS of 3.65 months (95% CI: 1.17, 7.90), gemcitabine-based regimens had a PFS of 2.80 months (95% CI: 1.83, 4.60), and other regimens had a PFS of 1.67 months (95% CI: 1.13, 7.77). CONCLUSION: MPT patients are a unique population with limited characterization to date. Our study demonstrates activity of multiple sarcoma-directed chemotherapy regimens, with ifosfamide-containing regimens having the longest PFS.

IGF-1R/mTOR Targeted Therapy for Ewing Sarcoma: A Meta-Analysis of Five IGF-1R-Related Trials Matched to Proteomic and Radiologic Predictive Biomarkers.

Background : Ten to fourteen percent of Ewing sarcoma (ES) study participants treated nationwide with IGF-1 receptor (IGF-1R)-targeted antibodies achieved tumor regression. Despite this success, low response rates and short response durations (approximately 7-weeks) have slowed the development of this therapy. Methods: We performed a meta-analysis of five phase-1b/2 ES-oriented trials that evaluated the anticancer activity of IGF-1R antibodies +/- mTOR inhibitors (mTORi). Our meta-analysis provided a head-to-head comparison of the clinical benefits of IGF-1R antibodies vs. the IGF-1R/mTOR-targeted combination. Available pretreatment clinical samples were semi-quantitatively scored using immunohistochemistry to detect proteins in the IGF-1R/PI3K/AKT/mTOR pathway linked to clinical response. Early PET/CT imaging, obtained within the first 2 weeks (median 10 days), were examined to determine if reduced FDG avidity was predictive of progression-free survival (PFS). Results: Among 56 ES patients treated at MD Anderson Cancer Center (MDACC) with IGF-1R antibodies, our analysis revealed a significant ~two-fold improvement in PFS that favored a combination of IGF-1R/mTORi therapy (1.6 vs. 3.3-months, p = 0.042). Low pIGF-1R in the pretreatment specimens was associated with treatment response. Reduced total-lesion glycolysis more accurately predicted the IGF-1R response than other previously reported radiological biomarkers. Conclusion: Synergistic drug combinations, and newly identified proteomic or radiological biomarkers of IGF-1R response, may be incorporated into future IGF-1R-related trials to improve the response rate in ES patients.

PET/CT Imaging as a Diagnostic Tool in Distinguishing Well-Differentiated versus Dedifferentiated Liposarcoma.

Distinguishing well-differentiated liposarcoma (WDLPS) from dedifferentiated liposarcoma (DDLPS) is essential given distinct treatment paradigms and chemosensitivity. Percutaneous biopsy has a low sensitivity for detecting DDLPS. We sought to identify the diagnostic utility of positron emission tomography/computed tomography (PET/CT) in identifying WDLPS versus DDLPS. An independent radiologist reviewed PET/CT images to identify target lesions and determine the maximum standardized uptake value (SUVmax). An independent pathologist review confirmed WDLPS or DDLPS histology. A binary cutoff point of SUVmax was identified using a classification and regression trees (CART) algorithm. We identified 20 patients with WDLPS or DDLPS with 26 PET/CTs performed for separate recurrences that were followed by surgical sampling. Of the 26 records, 12 were DDLPS (46%) and 14 were WDLPS (54%). Patients with DDLPS had significantly higher SUVmax than those with WDLPS (p value = 0.0035). A SUVmax of 4 was identified as the cutoff point. Using this cutoff, the sensitivity of SUVmax identifying a case as DDLPS was 83.3% (95% CI: 51.6%, 97.9%) and the specificity was 85.7% (95% CI: 57.2%, 98.2%). PET/CT is a sensitive and specific diagnostic tool to identify the presence of dedifferentiation within the tumor.

Adjuvant and Neoadjuvant Chemotherapy for Osteosarcoma: A Historical Perspective.

Osteosarcoma was initially resistant to chemotherapy that worked for Ewing sarcoma and rhabdomyosarcoma as well as other chemotherapeutic agents available in the 1960s. In the early 1970s, responses of osteosarcoma to adriamycin were reported, and at about the same time, so were responses of osteosarcoma to high-dose methotrexate. These agents were introduced into adjuvant therapy due to the dire prognosis associated with apparently localized osteosarcoma. After initial questions regarding the role of chemotherapy delayed its uniform acceptance, there is now general agreement that chemotherapy is primarily responsible for the cure of patients with osteosarcoma when combined with surgical elimination of the primary tumor. Advances with combination chemotherapy later adding cisplatin and ifosfamide have improved ultimate survival. The history of the development of effective chemotherapy combinations at Memorial Sloan Kettering Cancer Center, UT MD Anderson Cancer Center, and the Rizzoli Institute are highlighted, and recent large cooperative group studies are reviewed in the context of those findings.

Immuno-genomic landscape of osteosarcoma.

Limited clinical activity has been seen in osteosarcoma (OS) patients treated with immune checkpoint inhibitors (ICI). To gain insights into the immunogenic potential of these tumors, we conducted whole genome, RNA, and T-cell receptor sequencing, immunohistochemistry and reverse phase protein array profiling (RPPA) on OS specimens from 48 pediatric and adult patients with primary, relapsed, and metastatic OS. Median immune infiltrate level was lower than in other tumor types where ICI are effective, with concomitant low T-cell receptor clonalities. Neoantigen expression in OS was lacking and significantly associated with high levels of nonsense-mediated decay (NMD). Samples with low immune infiltrate had higher number of deleted genes while those with high immune infiltrate expressed higher levels of adaptive resistance pathways. PARP2 expression levels were significantly negatively associated with the immune infiltrate. Together, these data reveal multiple immunosuppressive features of OS and suggest immunotherapeutic opportunities in OS patients.

Systemic treatments in MDM2 positive intimal sarcoma: A multicentre experience with anthracycline, gemcitabine, and pazopanib within the World Sarcoma Network.

BACKGROUND: Intimal sarcoma (InS) is an exceedingly rare neoplasm with an unfavorable prognosis, for which new potentially active treatments are under development. We report on the activity of anthracycline-based regimens, gemcitabine-based regimens, and pazopanib in patients with InS. METHODS: Seventeen sarcoma reference centers in Europe, the United States, and Japan contributed data to this retrospective analysis. Patients with MDM2-positive InS who were treated with anthracycline-based regimens, gemcitabine-based regimens, or pazopanib between October 2001 and January 2018 were selected. Local pathological review was performed to confirm diagnosis. Response was assessed by RECIST1.1. Recurrence-free survival (RFS), progression-free survival (PFS) and overall survival were computed by Kaplan-Meier method. RESULTS: Seventy-two patients were included (66 anthracycline-based regimens; 26 gemcitabine-based regimens; 12 pazopanib). In the anthracycline-based group, 24 (36%) patients were treated for localized disease, and 42 (64%) patients were treated for advanced disease. The real-world overall response rate (rwORR) was 38%. For patients with localized disease, the median RFS was 14.6 months. For patients with advanced disease, the median PFS was 7.7 months. No anthracycline-related cardiac toxicity was reported in patients with cardiac InS (n = 26). For gemcitabine and pazopanib, the rwORR was 8%, and the median PFS was 3.2 and 3.7 months, respectively. CONCLUSION: This retrospective series shows the activity of anthracycline-based regimens in InS. Of note, anthracyclines were used in patients with cardiac InS with no significant cardiac toxicity. The prognosis in patients with InS remains poor, and new active drugs and treatment strategies are needed.

The degree of sclerosis is associated with prognosis in well-differentiated liposarcoma of the retroperitoneum.

BACKGROUND AND OBJECTIVES: Well-differentiated liposarcomas (WDL) are often partly composed of sclerotic tissue, however, the amount varies widely between tumors, and its prognostic significance is unknown. We hypothesized that tumors with more sclerosis would behave more aggressively. METHODS: Primary retroperitoneal WDL from 29 patients resected at our institution with follow-up were histologically evaluated by soft tissue pathologists blinded to outcome. Tumors with ≥ 10% sclerosis were designated "sclerotic" while tumors with < 10% sclerosis were designated as "minimally sclerotic". Cellular and dedifferentiated tumors were excluded. Clinical parameters and radiologic assessments on computed tomography (CT) were recorded. RESULTS: Histological evaluation identified 13 minimally sclerotic WDL and 16 sclerotic WDL. Median follow-up was 9 years (range, 3-20). Median recurrence-free survival (RFS) and median overall survival (OS) were 6.16 and 13.9 years, respectively. Compared with patients with sclerotic WDL, those with minimally sclerotic WDL had superior RFS (HR = 0.17 [95% CI, 0.06-0.53], P = .002) and OS (log-rank test, P = .002). Sclerotic WDL exhibited higher Houndsfield Units than minimally sclerotic WDL (26 vs 1, P = .040). CONCLUSIONS: Minimally sclerotic WDL were associated with more favorable outcome compared with sclerotic tumors. Assessment of sclerosis in WDL is likely a useful prognostic marker.

Alpha Particle Radium 223 Dichloride in High-risk Osteosarcoma: A Phase I Dose Escalation Trial.

PURPOSE: The prognosis of metastatic osteosarcoma continues to be poor. We hypothesized that alpha-emitting, bone-targeting radium 223 dichloride (223RaCl2) can be safely administered to patients with osteosarcoma and that early signals of response or resistance can be assessed by quantitative and qualitative correlative imaging studies and biomarkers. PATIENTS AND METHODS: A 3+3 phase I, dose-escalation trial of 223RaCl2 (50, 75, and 100 kBq/kg) was designed in patients with recurrent/metastatic osteosarcoma aged ≥15 years. Objective measurements included changes in standardized uptake values of positron emission tomography (PET; 18FDG and/or NaF-18) and single-photon emission CT/CT (99mTc-MDP) as well as alkaline phosphatase and bone turnover markers at baseline, midstudy, and the end of the study. RESULTS: Among 18 patients enrolled (including 15 males) aged 15-71 years, tumor locations included spine (n = 12, 67%), pelvis (n = 10, 56%), ribs (n = 9, 50%), extremity (n = 7, 39%), and skull (n = 2, 11%). Patients received 1-6 cycles of 223RaCl2; cumulative doses were 6.84-57.81 MBq. NaF PET revealed more sites of metastases than did FDG PET. One patient showed a metabolic response on FDG PET and NaF PET. Four patients had mixed responses, and one patient had a response in a brain metastasis. Bronchopulmonary hemorrhage from Grade 3 thrombocytopenia (N = 1) was a DLT. The median overall survival time was 25 weeks. CONCLUSIONS: The first evaluation of the safety and efficacy of an alpha particle in high-risk osteosarcoma shows that the recommended phase II dose for 223RaCl2 in osteosarcoma is 100 kBq/kg monthly (twice the dose approved for prostate cancer), with minimal hematologic toxicity, setting the stage for combination therapies.

Cytokines Produced by Dendritic Cells Administered Intratumorally Correlate with Clinical Outcome in Patients with Diverse Cancers.

Purpose: Dendritic cells (DC) initiate adaptive immune responses through the uptake and presentation of antigenic material. In preclinical studies, intratumorally injected activated DCs (aDCs; DCVax-Direct) were superior to immature DCs in rejecting tumors from mice.Experimental Design: This single-arm, open-label phase I clinical trial evaluated the safety and efficacy of aDCs, administered intratumorally, in patients with solid tumors. Three dose levels (2 million, 6 million, and 15 million aDCs per injection) were tested using a standard 3 + 3 dose-escalation trial design. Feasibility, immunogenicity, changes to the tumor microenvironment after direct injection, and survival were evaluated. We also investigated cytokine production of aDCs prior to injection.Results: In total, 39 of the 40 enrolled patients were evaluable. The injections of aDCs were well tolerated with no dose-limiting toxicities. Increased lymphocyte infiltration was observed in 54% of assessed patients. Stable disease (SD; best response) at week 8 was associated with increased overall survival. Increased secretion of interleukin (IL)-8 and IL12p40 by aDCs was significantly associated with survival (P = 0.023 and 0.024, respectively). Increased TNFα levels correlated positively with SD at week 8 (P < 0.01).Conclusions: Intratumoral aDC injections were feasible and safe. Increased production of specific cytokines was correlated with SD and prolonged survival, demonstrating a link between the functional profile of aDCs prior to injection and patient outcomes. Clin Cancer Res; 24(16); 3845-56. ©2018 AACR.