Background BRAFV600, NRAS, TP53 and BRAFNon-V600 are among the most common mutations detected in non-acral cutaneous melanoma (CM) patients. While several studies have identified clinical and pathologic features associated with BRAFV600 and NRAS mutations, limited data is available regarding the correlates and significance of TP53 and BRAFNon-V600 mutations. Methods We analyzed the patient demographics, primary tumor features, and clinical outcomes of a large cohort (n=926) of non-acral cutaneous melanoma patients that had undergone clinically-indicated molecular testing. Results The prevalence of BRAFV600, NRAS, TP53, and BRAFNon-V600 mutations were 43%, 21%, 19%, and 7%. The presence of a TP53 mutation was associated with older age (p=0.019), head and neck primary tumor site (p=0.0001), and longer overall survival (OS) from the diagnosis of stage IV disease on univariate (p=0.039) and multivariate (p=0.015) analyses. BRAFNon-V600 mutations were associated with older age (p=0.005), but no primary tumor features nor OS from stage IV. Neither TP53 nor BRAFNon-V600 mutations correlated significantly with OS with frontline ipilimumab treatment, and TP53 status was not significantly associated with outcomes with frontline BRAF inhibitor therapy. Eleven patients with BRAFNon-V600 mutations were treated with a BRAF inhibitor. Three patients were not evaluable for response due to treatment cessation for toxicities; the remaining patients had disease progression as the best response to therapy. Conclusions These results add to the understanding of the clinical features associated with TP53 and BRAFNon-V600 mutations in advanced CM patients, and they support the rationale to evaluate the prognostic significance of TP53 in other cohorts of melanoma patients.

Over the past 20 years, dendritic cells (DCs) have been utilized to activate immune responses capable of eliminating cancer cells. Currently, ex vivo DC priming has been the mainstay of DC cancer immunotherapies. However, cell-based treatment modalities are inherently flawed due to a lack of standardization, specialized facilities and personnel, and cost. Therefore, direct modes of DC manipulation, circumventing the need for ex vivo culture, must be investigated. To facilitate the development of next-generation, in vivo targeted DC vaccines, we characterized the DC interaction and activation potential of the Tobacco Mosaic virus (TMV), a plant virus that enjoys a relative ease of production and the ability to deliver protein payloads via surface conjugation. In this study we show that TMV is readily taken up by mouse bone marrow-derived DCs, in vitro. Footpad injection of fluorophore-labeled TMV reveals preferential uptake by draining lymph node resident DCs in vivo. Uptake leads to activation, as measured by the upregulation of key DC surface markers. When peptide antigen-conjugated TMV is injected into the footpad of mice, DC-mediated uptake and activation leads to robust antigen-specific CD8+ T cell responses, as measured by antigen-specific tetramer analysis. Remarkably, TMV priming induced a greater magnitude T cell response than Adenovirus (Ad) priming. Finally, TMV is capable of boosting either Ad-induced or TMV-induced antigen-specific T cell responses, demonstrating that TMV, uniquely, does not induce neutralizing self-immunity. Overall, this study elucidates the in vivo DC delivery and activation properties of TMV, and indicates its potential as a vaccine vector in stand alone or prime-boost strategies.

Oropharyngeal squamous cell carcinoma (OPSCC) incidence is increasing at a nearly epidemic rate, largely driven by the human papillomavirus (HPV). Despite the generally favorable clinical outcomes of patients with HPV driven (HPV+) OPSCC, a significant subset of HPV tumors associated with tobacco exposure have diminished treatment response and worse survival. The tumor immune microenvironment (TIME) has been shown to be a critical driver of treatment response and oncologic outcomes in OPSCC generally and HPV+ OPSCC more specifically. However, the impact of tobacco exposure on the TIME in OPSCC patients remains unclear. We analyzed the relationship between TIME, tobacco exposure and clinical outcomes in OPSCC patients (n = 143) with extensive tobacco exposure (median pack-years = 40). P16 overexpression, a surrogate marker of HPV association, was a strong predictor of relapse-free (RFS) and overall survival (OS) (p < 0.001, p < 0.001 respectively) regardless of tobacco exposure and associated strongly with differential infiltration of the tumor by both CD3 and CD8 lymphocytes measured via immunohistochemistry (p < 001, p < 0.001 respectively). CD3 and CD8 infiltration was a strong predictor of RFS and OS and associated strongly with disease stage (AJCC 8 th Edition Staging Manual). Tobacco exposure correlated significantly (p < 0.001) with decreased CD8 infiltration in p16+ OPSCC tumors. Our findings demonstrate that the HPV+ OPSCC clinical outcomes are strongly correlated with the TIME, which is potentially modulated by tobacco exposure. Immunomodulatory strategies targeting this disease in smokers must take into consideration the potential modifying effects of tobacco exposure on treatment effectiveness and clinical outcomes.

No abstract