ABSTRACT
New advancements in medicine have paved the way for targeted therapies and immune checkpoint inhibitors (ICIs), which have become mainstays of cancer therapy. Targeted therapies work by pinpointing specific molecules in cancer pathways and inhibiting their function, while ICIs target irregularities in the immune system and DNA repair, participating in the induction of cell death. Although these agents have demonstrated great efficacy in treating a diverse set of cancers, they can frequently provoke serious dermatologic adverse effects. The side effects caused by an ICI are classified as immune-related adverse events since ICIs are immunomodulating, while the cutaneous side effects of targeted therapies are known as dermatologic adverse effects. Multiple studies have reported psoriasis and psoriasiform eruptions among the side effects observed in neoplastic patients receiving targeted therapies or ICIs. Psoriasis is an immune-mediated disease characterized by overactive T-cells and keratinocytes. To conduct this review, we retrieved 1363 studies from the PubMed database published between 2008 and 2023 using the terms "psoriasis" AND "cancer treatment." Many of these studies aimed to understand how patients with cancer receiving treatment may develop or even achieve psoriasis remission. Given that cancer and psoriasis involve a delicate balance between immune activation and suppression, ICIs and targeted therapies might produce varying effects. The aim of this review was to explore the relationship between psoriasis and cancer therapeutics while also highlighting the need to prioritize proper management of cutaneous side effects in neoplastic patients.
ABSTRACT
Psoriasis is a complex disease triggered by genetic, immunologic, and environmental stimuli. Many genes have been linked to psoriasis, like the psoriasis susceptibility genes, some of which are critical in keratinocyte biology and epidermal barrier function. Still, the exact pathogenesis of psoriasis is unknown. In the disease, the balance between the proliferative and differentiative processes of keratinocytes becomes altered. Multiple studies have highlighted the role of dysregulated immune cells in provoking the inflammatory responses seen in psoriasis. In addition to immune cells, accumulating evidence shows that keratinocytes are involved in psoriasis pathogenesis, as discussed in this review. Although certain immune cell-derived factors stimulate keratinocyte hyperproliferation, activated keratinocytes can also produce anti-microbial peptides, cytokines, and chemokines that can promote their proliferation, as well as recruit immune cells to help initiate and reinforce inflammatory feedback loops. Psoriatic keratinocytes also show intrinsic differences from normal keratinocytes even after removal from the in vivo inflammatory environment; thus, psoriatic keratinocytes have been found to exhibit abnormal calcium metabolism and possible epigenetic changes that contribute to psoriasis. The Koebner phenomenon, in which injury promotes the development of psoriatic lesions, also provides evidence for keratinocytes' contributions to disease pathogenesis. Furthermore, transgenic mouse studies have confirmed the importance of keratinocytes in the etiology of psoriasis. Finally, in addition to immune cells and keratinocytes, data in the literature support roles for other cell types, tissues, and systems in psoriasis development. These other contributors are all potential targets for therapies, suggesting the importance of a holistic approach when treating psoriasis.
