Purpose: No universal circulating biomarker exists for soft-tissue sarcoma (STS) and bone sarcoma. We report the translational relevance of a Droplet Digital PCR (ddPCR) assay allowing universal, specific, and dynamic detection of sarcoma-related hypermethylated ctDNA. Experimental Design: In silico analysis (The Cancer Genome Atlas/Gene Expression Omnibus datasets, n = 8,330) identified hypermethylated DNA positions in STS/bone sarcoma, unmethylated in nonsarcoma tissues or white blood cells releasing circulating plasma cell-free DNA (cfDNA). A ddPCR assay following bisulfite conversion of cfDNA was developed. The methylation signature performances were evaluated in independent in silico cohorts (The Cancer Genome Atlas/Gene Expression Omnibus, n = 1,342). The ddPCR assay was applied to cfDNA from healthy donors, patients with metastatic STS (METASARC cohort, n = 49, 13 histotypes), and patients with STS/bone sarcoma treated with neoadjuvant chemotherapy (NEOSARC cohort, n = 42, 10 histotypes). Results: A ddPCR assay targeting seven methylated genomic positions distinguished sarcoma samples from nonneoplastic mesenchymal and endothelial/liver tissues (AUC = 0.95; in silico validation set). Sensitivity allowed methylated DNA detection at a 1:1,000 dilution in genomic DNA, with a methylated allele frequency of 0.06%. ctDNA was positively detected in 45% of METASARC (22/49) and 74% of NEOSARC (31/42) patients, across all histotypes. ctDNA detection correlated with poor overall survival in METASARC patients with STS (P = 0.039). Increasing ctDNA during neoadjuvant chemotherapy was associated with poor outcomes in NEOSARC (composite criteria with poor histologic response, radiological progression, or relapse within 6 months; P = 0.0095). Conclusions: This sensitive ddPCR assay for universally methylated ctDNA enables precise detection, prognostication, and real-time monitoring of tumor burden in patients with high-grade and advanced sarcoma, regardless of histotype or origin.

Background: Nivolumab improved patients’ survival in metastatic renal cell carcinoma (mRCC). We aimed to evaluate resting energy expenditure (REE) (i.e., patients’ basal metabolism) to predict efficacy. Methods: We conducted a monocentric, observational study of mRCC patients receiving nivolumab between October 2015 and May 2020. REE was measured prior to initiating immunotherapy using indirect calorimetry to determine hypo, normo and hypermetabolism. Primary endpoint was 6-month, progression-free survival (PFS), and secondary endpoints were response rate, PFS and overall survival (OS). Results: Of the 51 consecutive patients, 15 (29%) were hypermetabolic, 24 (47%) normometabolic, and 12 (24%) hypometabolic. The 6-month PFS was 15% for hypermetabolic patients and 65% for non-hypermetabolic patients (p < 0.01). In the multivariate analysis, hypermetabolism was the only baseline factor predicting 6-month PFS (OR 9.91, 95%CI [1.62–60.55], p = 0.01). Disease progression was noted as the best response in 73% of hypermetabolic patients and 26% of non-hypermetabolic patients (p = 0.02). Median PFS was 2.8 and 8.7 months (p < 0.01), and median OS was 20.2 and 35.1 months (p = 0.13) in the hypermetabolic and non-hypermetabolic groups, respectively. Conclusions: Our study identifies an association between mRCC patients’ energy expenditure and nivolumab efficacy. The measurement of REE by indirect calorimetry in routine practice could help identify patients at risk of nivolumab failure.

Bone metastases occur in one third of patients with metastatic clear cell renal cell carcinoma (mccRCC) and are associated with poor prognosis. Optimal first-line treatment for this subgroup of patients remains undefined. We conducted a multicenter retrospective study of patients with bone-metastatic (BM+) mccRCC treated with first-line immune checkpoint inhibitor (ICI)-based combinations between January 2015 and February 2024 across 8 French centers. The primary endpoint was time to next treatment (TTNT). Secondary endpoints included overall survival (OS), bone progression-free survival (bPFS), incidence of skeletal-related events (SREs) and changes in bone pain. A total of 124 patients were included; 55% received ICI-ICI and 45% an ICI plus a tyrosine kinase inhibitor (TKI). Median follow-up was 36.8 months. Median TTNT was 11.7 months (95% CI, 8.38-20.0), OS 28.8 months (95% CI, 23.7-40.2) and bPFS 11.7 months (95% CI, 7.69-21.7). Median TTNT was numerically longer with ICI-TKI compared to ICI-ICI (17.9 vs. 8.5 months; P = .40), with no significant difference in OS or bPFS between treatment groups. SREs occurred in 32% of patients. Bone progression was observed in 48%, with a concomitant SRE in 54% mostly involving preexisting lesions (78%). Bone pain improved in 45% of evaluable patients. No significant differences were observed between treatment groups for SRE incidence or bone pain improvement. Hypercalcemia was associated with shorter OS and bPFS, while bone-only disease correlated with improved OS. Use of bone-targeting agents (BTAs) was independently associated with longer bPFS. ICI-CI and ICI-TKI combinations showed comparable outcomes in BM+ mccRCC. Bone progression and SREs remained frequent and often involved preexisting bone lesions. These findings support early integration of local treatments as well as BTAs, which were independently associated with longer bPFS.

Purpose:No universal circulating biomarker exists for soft-tissue sarcoma (STS) and bone sarcoma. We report the translational relevance of a Droplet Digital PCR (ddPCR) assay allowing universal, specific, and dynamic detection of sarcoma-related hypermethylated ctDNA.Experimental Design:In silico analysis (The Cancer Genome Atlas/Gene Expression Omnibus datasets, n = 8,330) identified hypermethylated DNA positions in STS/bone sarcoma, unmethylated in nonsarcoma tissues or white blood cells releasing circulating plasma cell-free DNA (cfDNA). A ddPCR assay following bisulfite conversion of cfDNA was developed. The methylation signature performances were evaluated in independent in silico cohorts (The Cancer Genome Atlas/Gene Expression Omnibus, n = 1,342). The ddPCR assay was applied to cfDNA from healthy donors, patients with metastatic STS (METASARC cohort, n = 49, 13 histotypes), and patients with STS/bone sarcoma treated with neoadjuvant chemotherapy (NEOSARC cohort, n = 42, 10 histotypes).Results:A ddPCR assay targeting seven methylated genomic positions distinguished sarcoma samples from nonneoplastic mesenchymal and endothelial/liver tissues (AUC = 0.95; in silico validation set). Sensitivity allowed methylated DNA detection at a 1:1,000 dilution in genomic DNA, with a methylated allele frequency of 0.06%. ctDNA was positively detected in 45% of METASARC (22/49) and 74% of NEOSARC (31/42) patients, across all histotypes. ctDNA detection correlated with poor overall survival in METASARC patients with STS (P = 0.039). Increasing ctDNA during neoadjuvant chemotherapy was associated with poor outcomes in NEOSARC (composite criteria with poor histologic response, radiological progression, or relapse within 6 months; P = 0.0095).Conclusions:This sensitive ddPCR assay for universally methylated ctDNA enables precise detection, prognostication, and real-time monitoring of tumor burden in patients with high-grade and advanced sarcoma, regardless of histotype or origin.