Cutaneous squamous cell carcinoma (CSCC) accounts for approximately 20% of all keratinocytic tumors. In most cases, the diagnosis and treatments are made on small, low-risk lesions. However, in about 5% of cases, CSCC may present as either locally advanced or metastatic (i.e. with locoregional lymph nodes metastases or distant localizations). Prior to the introduction of immunotherapy in clinical practice, the standard treatment of advanced CSCC was not clearly defined, and up to 60% of patients received no systemic therapy. Thanks to a strong pre-clinical rationale, clinical trials led to the FDA (Food and Drug Administration) and EMA (European Medicines Agency) registration of cemiplimab, a PD-1 inhibitor that achieved encouraging results in terms of objective response, overall survival, and quality of life. Subsequently, the anti-PD-1 pembrolizumab received the approval for the treatment of advanced CSCC by the FDA only. In this review, we will focus on the definition of advanced CSCC and on the current and future therapeutic options, with a particular regard for immunotherapy.

Uveal melanoma (UM), though a rare form of melanoma, is the most common intraocular tumor in adults. Conventional therapies of primary tumors lead to an excellent local control, but 50% of patients develop metastases, in most cases with lethal outcome. Somatic driver mutations that act on the MAP-kinase pathway have been identified, yet targeted therapies show little efficacy in the clinics. No drugs are currently available for the G protein alpha subunitsGNAQ and GNA11, which are the most frequent driver mutations in UM. Drugs targeting the YAP–TAZ pathway that is also activated in UM, the tumor-suppressor gene BRCA1 Associated Protein 1 (BAP1) and the Splicing Factor 3b Subunit 1 gene (SF3B1) whose mutations are associated with metastatic risk, have not been developed yet. Immunotherapy is highly effective in cutaneous melanoma but yields only poor results in the treatment of UM: anti-PD-1 and anti-CTLA-4 blocking antibodies did not meet the expectations except for isolated cases. Here, we discuss how the improved knowledge of the tumor microenvironment and of the cross-talk between tumor and immune cells could help to reshape anti-tumor immune responses to overcome the intrinsic resistance to immune checkpoint blockers of UM. We critically review the dogma of low mutational load, the induction of immune-suppressive cells, and the expression of alternative immune checkpoint molecules. We argue that immunotherapy might still be an option for the treatment of UM.

Background There is a concern that influenza vaccination may increase the incidence of immune‐related adverse events in patients receiving immune checkpoint inhibitors (ICIs). The aim of this systematic review was to summarize the available data on the safety and efficacy of influenza vaccination in cancer patients receiving ICIs. Methods Studies reporting safety and efficacy outcomes of influenza vaccination in cancer patients receiving ICIs were included. Only descriptive statistics were conducted to obtain a pooled rate of immune‐related adverse events in vaccinated patients. Results Ten studies assessing the safety and eight assessing the efficacy of influenza vaccination in cancer patients receiving ICIs were identified, for a total of 1124 and 986 vaccinated patients, respectively. Most patients had melanoma or lung cancer and received a single agent anti‐PD‐1, but also other tumour types and immunotherapy combinations were represented. No severe vaccination‐related toxicities were reported. The pooled incidence of any grade immune checkpoint inhibitor–related adverse events was 28.9%. In the 6 studies specifying the incidence of grade 3‐4 toxicities, the pooled incidence was 7.5%. No grade 5 toxicities were reported. No pooled descriptive analysis was conducted in studies reporting efficacy outcomes due to the heterogeneity of endpoints and data reporting. Nevertheless, among the eight studies included, seven reported positive efficacy outcomes of influenza vaccination. Conclusion The results of this systematic review support the safety and efficacy of influenza vaccination in cancer patients receiving ICIs. These results are particularly relevant in the context of the SARS‐CoV‐2 pandemic.