Discordance Between the Initial Diagnosis of Sarcomas and Subsequent Histopathological Revision and Molecular Analyses in a Sarcoma Reference Center in Brazil.

PURPOSE: To investigate the discordance in sarcoma diagnoses between nonspecialized institutions following revision by dedicated sarcoma pathologists at a reference center in Brazil and the relevance of molecular pathology in this context. METHODS: We conducted a retrospective analysis of sarcoma samples initially analyzed at outside laboratories and subsequently reviewed by two specialized pathologists between January 2014 and December 2020. After obtaining demographic and tumor characteristics, pathology results were matched and classified as complete discordance (CD; benign v malignant, sarcoma v other malignancies), partial concordance (similar diagnosis of connective tumor, but different grade/histological subtype/differentiation), and complete concordance (CC). The concordance for histology or grade, and the role of molecular assessments supporting the diagnosis were also independently determined. Statistical analyses were conducted through the kappa coefficient of agreement and adherence by χ2 test, χ2 test by Person, and Fisher exact test. RESULTS: In total, 197 cases were included, with samples obtained predominately from male patients (57.9%) and localized/primary tumors (86.8%). Following revision, the most frequent final diagnoses were undifferentiated pleomorphic sarcoma (17.8%), well-differentiated/dedifferentiated liposarcoma (8.6%), and leiomyosarcoma (7.6%). CD was found in 13.2%, partial discordance in 45.2%, and CC in 41.6% of reviews (P < .001). We found a concordance for histology or grade of 53.5% (P < .001) and 51.8% (P < .001), respectively. Molecular assessments, comprising next-generation sequencing panels (79.5%) and fluorescent in situ hybridization (20.5%), were performed in 44 (22.3%) cases, with findings classified as of diagnostic relevance in 31.8%. CONCLUSION: In nearly 60% of the cases, the initial sarcoma diagnosis was modified when revised by a reference center and dedicated pathologists, assisted by molecular pathology techniques. These results justify the assembly of referral networks in countries with limited health care resources.

A phase 2 study of first-line nivolumab in patients with locally advanced or metastatic cutaneous squamous-cell carcinoma.

BACKGROUND: Cutaneous squamous-cell carcinoma (CSCC) is among the most frequent malignancies worldwide. For those not amenable to treatment with curative intent, immune checkpoint inhibition (ICI) with anti-programmed death receptor 1 (PD-1) antibodies has emerged as a novel therapeutic option. In this study, the authors sought to investigate the activity of the anti-PD-1 agent nivolumab in patients with advanced CSCC (aCSCC). METHODS: CA209-9JC was an open-label, single-arm, phase 2 study to evaluate the safety and/or efficacy of nivolumab in systemic treatment-naive patients with aCSCC. Nivolumab (3 mg/kg) was administered every 2 weeks until disease progression, unacceptable toxicity, or 12 months of treatment. The primary end point was the best objective response rate (BORR) as per RECIST 1.1 criteria. Secondary end points included safety, progression-free survival (PFS), and overall survival (OS). RESULTS: Twenty-four patients with aCSCC were enrolled with a median age of 74 years (range, 48-93). Among the 24 patients evaluable for response, the BORR was 58.3% (14/24); there were no complete responses. With a median follow-up of 17.6 months, median duration of response has not been reached, and the estimated median PFS and OS were 12.7 and 20.7 months, respectively. Prior exposure to radiotherapy was associated with worse outcomes (p = .035, univariate analysis). Treatment-related adverse events of any grade and grade ≥ 3 occurred in 21 (87.5%) and six (25%) patients, respectively, and one patient discontinued nivolumab due to toxicities. CONCLUSIONS: Nivolumab resulted in robust antitumor activity, sustained responses, and good tolerability in systemic treatment-naive patients with aCSCC. These data provide further evidence to support the use of ICI as the standard treatment of aCSCC.