One of several comorbidities associated with chronic inflammatory skin diseases, namely psoriasis, is cancer. Although a chronic inflammatory state may cause protumorigenic effects, there is debate as to whether drugs used in clinical practice play a leading role in tumor development. Recently, the therapeutic arsenal for the treatment of immune-mediated chronic systemic diseases has expanded significantly due to the emergence of heterogeneous groups of biological drugs that affect the immune system. A lot of controversy raises questions about whether the development of malignant tumors (MNT) is a side effect of treatment with biological drugs. The article discusses the risks of developing cancer in patients with psoriasis and their relationship, approaches to the management of patients diagnosed with psoriasis and cancer, modern ideas about immunological disorders during the development of cancer, a review of studies on the role of genetically engineered biological therapy (GEBT) drugs from various groups in development of tumors of various localizations. Patients with psoriasis often have a history of concomitant diseases, which makes it difficult to select the necessary treatment, however, the severity of skin manifestations requires systemic treatment. We present a clinical case from practice about the use of GIBT with an interleukin-17 inhibitor (IL-17) in a patient with widespread severe psoriasis and a history of prostate cancer. Increased preclinical evidence has also demonstrated that the balance between IL-12 and IL-23 is critical in carcinogenesis and that disruption of IL-12 and/or IL-23 signalling both promotes and suppresses tumour growth. Although the mechanisms underlying these biological activities have not been studied in depth and the interpretation of preclinical studies on the involvement of IL-12 and IL-23 in tumour biology is controversial, the clinical studies indicate that IL-23 inhibitors are drugs with a favourable safety profile.