Expression and prognostic significance of PDGF ligands and receptors across soft tissue sarcomas
Mehdi Brahmi, Tom Lesluyes, Armelle Dufresne, Maud Toulmonde, Antoîne Italiano, Olivier Mir, Axel Le Cesne, Thibaud Valentin, Christine Chevreau, Sylvie Bonvalot, Nicolas Penel, Jean‐Michel Coindre, Sophie Le Guellec, François Le Loarer, Marie Karanian, Jean‐Yves Blay, Frédéric Chibon
Abstract
•The expression of PDGF ligands and receptors substantially varies across sarcoma histological subtypes.•PDGFA and D expression levels independently and inversely correlate with the risk of metastatic relapse.•The differential expression of ligands might be used as biomarker of efficacy for PDGFRα antibodies in STS. BackgroundWhile the anti-PDGFRA antibody olaratumab failed to confirm an impact on survival in unselected advanced soft tissue sarcoma (STS) patients, the level of expression and the prognosis of platelet-derived growth factor (PDGF) receptors and ligands in STS remain unclear.Patients and methodsWe analyzed PDGF ligands and receptors' expression levels in a series of 255 patients with different histologies of STS [gastrointestinal stromal tumor (GIST), myxoid liposarcoma (MLPS), sarcoma with complex genomics, synovial sarcoma (SyS)] with Agilent single-color micro-arrays. We explored expression levels as prognostic values in univariate and multivariate analysis using R software (version 3.4.2).ResultsComplex patterns of correlation of expression between ligands and receptors were observed for each histotype. PDGFA levels were highest in SyS and lowest in MLPS (P < 4 × 10−9), PDGFB and C levels were lower in GIST (P < 2 × 10−15 and P < 3 × 10−9) while PDGFD expression was similar across histological subtypes. PDGF receptor (PDGFR) A expression was lowest in MLPS (P < 0.002), whereas PDGFRB and L expressions were lowest in GIST and SyS (P < 0.0004). Interestingly, high PDGFA expression levels were associated with higher risk of metastasis (P = 0.006), whereas PDGFD levels above average were associated with a reduced risk of metastasis (P = 0.01) in univariate and multivariate analysis.ConclusionsThe expression of PDGF ligands and receptors varies across sarcoma histological subtypes. PDGFA and D expression levels independently and inversely correlate with the risk of metastatic relapse. While the anti-PDGFRA antibody olaratumab failed to confirm an impact on survival in unselected advanced soft tissue sarcoma (STS) patients, the level of expression and the prognosis of platelet-derived growth factor (PDGF) receptors and ligands in STS remain unclear. We analyzed PDGF ligands and receptors' expression levels in a series of 255 patients with different histologies of STS [gastrointestinal stromal tumor (GIST), myxoid liposarcoma (MLPS), sarcoma with complex genomics, synovial sarcoma (SyS)] with Agilent single-color micro-arrays. We explored expression levels as prognostic values in univariate and multivariate analysis using R software (version 3.4.2). Complex patterns of correlation of expression between ligands and receptors were observed for each histotype. PDGFA levels were highest in SyS and lowest in MLPS (P < 4 × 10−9), PDGFB and C levels were lower in GIST (P < 2 × 10−15 and P < 3 × 10−9) while PDGFD expression was similar across histological subtypes. PDGF receptor (PDGFR) A expression was lowest in MLPS (P < 0.002), whereas PDGFRB and L expressions were lowest in GIST and SyS (P < 0.0004). Interestingly, high PDGFA expression levels were associated with higher risk of metastasis (P = 0.006), whereas PDGFD levels above average were associated with a reduced risk of metastasis (P = 0.01) in univariate and multivariate analysis. The expression of PDGF ligands and receptors varies across sarcoma histological subtypes. PDGFA and D expression levels independently and inversely correlate with the risk of metastatic relapse.