Overall survival in patients with re-excision of positive microscopic margins of limb and trunk wall soft tissue sarcoma operated outside of a reference center: a nationwide cohort analysis.

BACKGROUND: This French nationwide NETSARC exhaustive prospective cohort aims to explore the impact of systematic re-excision (RE) as adjuvant care on overall survival (OS), local recurrence free survival (LRFS), and local and distant control (RFS) in patients with soft tissue sarcoma (STS) with positive microscopic margins (R1) after initial resection performed outside of a reference center. METHODS: Eligible patients had experienced STS surgery outside a reference center from 2010 to 2017, and had R1 margins after initial surgery. Characteristics and treatment comparisons used chi-square for categorical variables and Kruskall-Wallis test for continuous data. Survival distributions were compared in patients reexcised (RE) or not (No-RE) using a log-rank test. A Cox proportional hazard model was used for subgroup analysis. RESULTS: A total of 1,284 patients had experienced initial STS surgery outside NETSARC with R1 margins, including 1,029 patients with second operation documented. Among the latter, 698 patients experienced re-excision, and 331 were not re-excised. Characteristics were significantly different regarding patient age, tumor site, tumor size, tumor depth, and histotype in the population of patients re-excised (RE) or not (No-RE). The study identified RE as an independent favorable factor for OS (HR 0.36, 95%CI 0.23-0.56, p<0.0001), for LRFS (HR 0.45, 95%CI 0.36-0.56, p<0.0001), and for RFS (HR 0.35, 95%CI 0.26-0.46, p<0.0001). CONCLUSION: This large nationwide series shows that RE improved overall survival in patients with STS of extremities and trunk wall, with prior R1 resection performed outside of a reference center. RE as part of adjuvant care should be systematically considered.

Long-Term Outcome of Neoadjuvant Tyrosine Kinase Inhibitors Followed by Complete Surgery in Locally Advanced Dermatofibrosarcoma Protuberans.

In locally advanced dermatofibrosarcoma protuberans (DFSP), imatinib mesylate has been described as an efficient neoadjuvant therapy. This retrospective study included patients with locally advanced DFSP who received neoadjuvant TKI (imatinib or pazopanib) from 2007 to 2017 at Saint Louis Hospital, Paris. The primary endpoint was the evaluation of the long-term status. A total of 27 patients were included, of whom nine had fibrosarcomatous transformation. The median duration of treatment was 7 months. The best response to TKI treatment before surgery, evaluated according to RECIST1.1 on MRI, consisted of complete/partial response (38.5%) or stability (46.2%). DFSP was surgically removed in 24 (89%) patients. A total of 23 patients (85%) were disease-free after 64.8 months of median follow-up (95% confidence interval 47.8; 109.3). One patient developed distant metastases 37 months after surgical tumor resection and finally died. Two patients (7%) did not get surgery because of metastatic progression during TKI treatment, and one patient refused surgery even though the tumor decreased by 30%. Treatment-related adverse events (AE) occurred in 23 patients (85%). Only four patients (imatinib: n = 3, pazopanib: n = 1) had grade ≥3 AE requiring temporary treatment disruption. Neoadjuvant TKI followed by complete surgery with micrographic analysis is an effective strategy for locally advanced and unresectable DFSP, with durable local recurrence disease-free survival.

A Melanoma-Tailored Next-Generation Sequencing Panel Coupled with a Comprehensive Analysis to Improve Routine Melanoma Genotyping.

BACKGROUND: Tumor molecular deciphering is crucial in clinical management. Pan-cancer next-generation sequencing panels have moved towards exhaustive molecular characterization. However, because of treatment resistance and the growing emergence of pharmacological targets, tumor-specific customized panels are needed to guide therapeutic strategies. OBJECTIVE: The objective of this study was to present such a customized next-generation sequencing panel in melanoma. METHODS: Melanoma patients with somatic molecular profiling performed as part of routine care were included. High-throughput sequencing was performed with a melanoma tailored next-generation sequencing panel of 64 genes involved in molecular classification, prognosis, theranostic, and therapeutic resistance. Single nucleotide variants and copy number variations were screened, and a comprehensive molecular analysis identified clinically relevant alterations. RESULTS: Four hundred and twenty-one melanoma cases were analyzed (before any treatment initiation for 94.8% of patients). After bioinformatic prioritization, we uncovered 561 single nucleotide variants, 164 copy number variations, and four splice-site mutations. At least one alteration was detected in 368 (87.4%) lesions, with BRAF, NRAS, CDKN2A, CCND1, and MET as the most frequently altered genes. Among patients with BRAFV600 mutated melanoma, 44.5% (77 of 173) harbored at least one concurrent alteration driving potential resistance to mitogen-activated protein kinase inhibitors. In patients with RAS hotspot mutated lesions and in patients with neither BRAFV600 nor RAS hotspot mutations, alterations constituting potential pharmacological targets were found in 56.9% (66 of 116) and 47.7% (63 of 132) of cases, respectively. CONCLUSIONS: Our tailored next-generation sequencing assay coupled with a comprehensive analysis may improve therapeutic management in a significant number of patients with melanoma. Updating such a panel and implementing multi-omic approaches will further enhance patients' clinical management.

Discoidin domain receptors: A promising target in melanoma.

The discoidin domain receptor 1 (DDR1) is a member of the receptor tyrosine kinase family that signals in response to collagen and that has been implicated in cancer progression. In the present study, we investigated the expression and role of DDR1 in human melanoma progression. Immunohistochemical staining of human melanoma specimens (n = 52) shows high DDR1 expression in melanoma lesions that correlates with poor prognosis. DDR1 expression was associated with the clinical characteristics of Clark level and ulceration and with BRAF mutations. Downregulation of DDR1 by small interfering RNA (siRNA) in vitro inhibited melanoma cells malignant properties, migration, invasion, and survival in several human melanoma cell lines. A DDR tyrosine kinase inhibitor (DDR1-IN-1) significantly inhibited melanoma cell proliferation in vitro, and ex vivo and in tumor xenografts, underlining the promising potential of DDR1 inhibition in melanoma.

A targeted genomic alteration analysis predicts survival of melanoma patients under BRAF inhibitors.

Several mechanisms have been described to elucidate the emergence of resistance to MAPK inhibitors in melanoma and there is a crucial need for biomarkers to identify patients who are likely to achieve a better and long-lasting response to BRAF inhibitors therapy. In this study, we developed a targeted approach combining both mRNA and DNA alterations analysis focusing on relevant gene alterations involved in acquired BRAF inhibitor resistance. We collected baseline tumor samples from 64 melanoma patients at BRAF inhibitor treatment initiation and showed that the presence, prior to treatment, of mRNA over-expression of genes' subset was significantly associated with improved progression free survival and overall survival. The presence of DNA alterations was in favor of better overall survival. The genomic analysis of relapsed-matched tumor samples from 20 patients allowed us to uncover the largest landscape of resistance mechanisms reported to date as at least one resistance mechanism was identified for each patient studied. Alterations in RB1 have been most frequent and hence represent an important additional acquired resistance mechanism. Our targeted genomic analysis emerges as a relevant tool in clinical practice to identify those patients who are more likely to achieve durable response to targeted therapies and to exhaustively describe the spectrum of resistance mechanisms. Our approach can be adapted to new targeted therapies by including newly identified genetic alterations.