Angiosarcomas (AS) are extremely rare and aggressive vascular malignancies subdivided in de novo primary AS (pAS) and secondary AS (sAS). We hypothesize that the combination of immunological and genomic profiles significantly differs between primary and secondary AS, with potential impact on treatment strategies and a role for immunotherapy. Tumor-infiltrating lymphocytes were analyzed using multiplex immunohistochemistry from 79 pAS and 178 sAS. Median cell density was significantly higher in sAS for CD3⁺ T-cells (p < 0.001), CD8⁺ cytotoxic T-cells (p = 0.033), CD4⁺ T-helper cells (p < 0.001) and FoxP3⁺ T-regulatory cells (p < 0.001). CD20⁺ B-cell density was comparable (p = 0.417). Comprehensive genomic profiling was performed in 25 pAS and 25 sAS. A (likely) pathogenic mutation was detected in 80% of pAS vs. 88% of sAS (p = 0.702). Amplifications were found in 15% of pAS vs. 84% of sAS (p < 0.001). DNA damage response (DDR) pathway mutations (p = 0.021) and MYC amplifications (p < 0.001) were predominantly seen in sAS. In conclusion we observed a clear and clinical relevant distinction in immune infiltration and genomic profiles between pAS and sAS. The T-cell infiltrated tumor microenvironment and frequent DDR gene mutations, especially in sAS, warrant clinical trials with immunotherapy.

To improve local control, neoadjuvant radiotherapy (nRT) followed by surgery is the standard of care in myxofibrosarcoma (MFS) because of its infiltrative growth pattern. Nevertheless, local recurrence rates are high. Data on prognostic factors for poor clinical outcomes are lacking. This retrospective study thus investigates the prognostic relevance of magnetic resonance imaging (MRI) characteristics before and after nRT in 40 MFS patients, as well as their association with disease-free survival (DFS) and overall survival (OS). A vascular pedicle, defined as extra-tumoral vessels at the tumor periphery, was observed in 12 patients (30.0%) pre-nRT and remained present post-nRT in all cases. Patients with a vascular pedicle had worse DFS (HR 5.85; 95% CI 1.56–21.90; p = 0.009) and OS (HR 9.58; 95% CI 1.91–48.00; p = 0.006). An infiltrative growth pattern, referred to as a tail sign, was observed in 22 patients (55.0%) pre-nRT and in 19 patients (47.5%) post-nRT, and was associated with worse DFS post-nRT (HR 6.99; 95% CI 1.39–35.35; p = 0.019). The percentage of tumor necrosis estimated by MRI was increased post-nRT, but was not associated with survival outcomes. The presence of a tail sign or vascular pedicle on MRI could support the identification of patients at risk for poor clinical outcomes after nRT.

Purpose: Angiosarcomas (AS) are rare vascular sarcomas. Secondary AS (sAS) arise from DNA-damaging factors such as radiotherapy and UV radiation (UV-AS) or due to chronic lymphedema. The prognosis for advanced AS is poor, with limited treatment options. Immune checkpoint inhibition is not approved for AS, but high intratumoral T-cell density and frequent mutations in sAS may support efficacy. Patients and Methods: This prospective, single-arm, multicenter phase II trial assessed the efficacy and safety of cemiplimab (350 mg, intravenously every 3 weeks) in patients with locally advanced or metastatic sAS using a Simon’s two-stage design. The primary outcome was the best overall response rate within 24 weeks of treatment. Secondary outcomes included time to response, duration of response, progression-free survival, overall survival, and predictive biomarkers for treatment response. Results: Eighteen patients (12 with AS from radiotherapy, 3 with UV-AS, and 3 with AS due to chronic lymphedema) were treated with cemiplimab. The best overall response rate was 27.8% (4 partial responses, 1 complete response), with a time to response of 2.6 months and a duration of response of 6.9 months. The median progression-free survival was 3.7 months, and the median overall survival was 13.1 months. Grade ≥3 immune-related adverse events occurred in 33.3% of patients. High tumor mutational burden was observed in three patients with UV-AS, two of whom showed a response. High intratumoral CD3+ (P = 0.019), CD4 (P = 0.046), CD8+ (P = 0.026), and FoxP3+ (P = 0.026) T-cell densities; low platelet-to-lymphocyte ratio (P = 0.026); and Colidextribacter abundance were associated with response. Conclusions: Cemiplimab shows promising effectivity in sAS and warrants further investigation. Promising predictive blood and tissue biomarkers were identified, indicating potential for improved patient selection.

Introduction: Immune checkpoint inhibition (ICI) is highly effective for the treatment of melanoma, but intrinsic resistance is present in a subgroup of patients. TGF-β pathway activity may play a role in this resistance by preventing T-cells from entering the tumor microenvironment, causing immune escape. We investigated the association of TGF-β signal transduction pathway activity with resistance to ICI treatment in advanced melanoma. Furthermore, other pathway activities were analyzed to better understand their potential role in ICI resistance. Method: The activity of 8 signaling pathways (TGF-β, Hedgehog, MAPK, AR, NOTCH, PI3K, JAK/STAT1-2, and NFkB) was analyzed from tumor tissue from patients with advanced melanoma. Pathway activity scores (PAS) were explored for associations with survival and response to ICI in 34 patients (19 non-responders and 15 responders). A second, independent method to investigate the predictive value of TGF-β pathway activation was conducted by determining levels of phosphorylated SMAD2. Results: The mean TGF-β PAS of responders vs non-responders was 53.9 vs 56.8 (P = 0.265). No significant relation with progression-free survival was detected for TGF-β activity (P = 0.078). No association between pSMAD2 staining and treatment response or survival was identified. In contrast, Hedgehog scores of responders versus non-responders were 35.7 vs 41.6 (P = 0.038). High Hedgehog PAS was the sole significant predictor of resistance to ICI (OR 0.88, P = 0.033) and worse progression-free survival (HR 1–1.1, P = 0.012). Conclusion: TGF-β pathway activation showed no significant relation with treatment response to ICI or survival in patients with advanced melanoma. Hedgehog PAS was identified as a possible biomarker associated with both treatment response and survival.

Objective Oxaliplatin is a cytotoxic agent frequently used in the treatment of gastrointestinal cancer patients. A known side effect of oxaliplatin administration via a peripheral vein is infusion-related pain. In this retrospective cohort study we compared the incidence of infusion-related pain in patients treated with oxaliplatin with or without simultaneous fluid infusion (FI) (800 mL glucose 5% in 2 hours). Methods We retrospectively defined two cohorts: Patients treated with oxaliplatin and simultaneous intravenous FI and the same number of patients treated without FI. The incidence of infusion-related venous pain was the primary outcome measure. Secondary outcomes included: Incidence of hypersensitivity reactions, infusion time, dose density, number of patients switched to a central venous catheter and incidence of peripheral neuropathy. Results 100 patients were included, 50 patients in both groups. Baseline characteristics were comparable, except for age (median 66.8 vs 62.4 years in groups with and without FI; p=0.017), and body mass index (28.0 vs 25.7 kg/m2, respectively; p=0.012). Patients treated with simultaneous FI experienced significantly less vascular pain compared with those without FI (10% vs 78%, respectively; p<0.0001; OR 0.031 (95% CI: 0.01 to 0.098)). No difference was observed in dose density, treatment delay or the need of central venous catheter. Logistic regression analysis showed no confounders affecting the primary outcome. No adverse events of FI were observed. Conclusion Concurrent infusion of 800 mL glucose 5% with peripheral venous administration of oxaliplatin significantly reduces the incidence of infusion-related pain in gastrointestinal cancer patients and is highly feasible and affordable in everyday clinical practice.