Remodeling of dermal adipose tissue alleviates cutaneous toxicity induced by anti-EGFR therapy

Anti-epidermal growth factor receptor (EGFR) therapy associated cutaneous toxicity is a syndrome characterized by papulopustular rash, local inflammation, folliculitis and microbial infection, resulting in a decrease in quality of life and dose interruption. However, no effective clinical intervention is available for this adverse effect. Here, we report the atrophy of dermal white adipose tissue (dWAT), a highly plastic adipose tissue with various skin-specific functions, correlates with rash occurrence and exacerbation in a murine model of EGFR inhibitor-induced rash. The reduction in dWAT is due to the inhibition of adipogenic differentiation by defects in peroxisome proliferator-activated receptor γ (PPARγ) signaling, and increased lipolysis by the induced expression of the lipolytic cytokine IL6. The activation of PPARγ by rosiglitazone maintains adipogenic differentiation and represses the transcription of IL6, eventually improving skin functions and ameliorating the severity of rash without altering the antitumor effects. Thus, activation of PPARγ represents a promising approach to ameliorate cutaneous toxicity in patients with cancer who receive anti-EGFR therapy.

Methotrexate Toxicity: Molecular Mechanisms and Management

Methotrexate (MTX) is the most widely used drug in cancer chemotherapy and is considered to be the first-line drug for the treatment of a number of rheumatic and non-rheumatic disorders. The pulmonary toxicity, hepatotoxicity of MTX are two of its major side effects. Other toxicities such as endocrinological toxicity, GI toxicity, cutaneous toxicity, hematological toxicity, fatal malfunction or loss, and malignancy can also occur, but at a significantly lower rate of prevalence. This review aims to provide a comprehensive understanding of the molecular mechanisms of methotrexate toxic effects and Lastly, we discussed the management of this toxicity.

Some aspects of nivolumab administration in treatment for metastatic melanoma (clinical cases)

The development of a new direction in anticancer medical therapy – the use of immune checkpoint inhibitors targeting PD-1/ PD-L1 and CTLA-4 – has significantly changed the approach to tumor treatment in the last few years. The PD1 blocker nivolumab in major registered clinical trials improved overall survival, including in metastatic melanoma, with a favorable toxicity profile. However, its efficacy in patients with brain metastases from melanoma was poorly studied, since the inclusion criteria for most clinical trials do not envisage recruiting such patients. The immune-mediated toxicity of immune checkpoint inhibitors is currently well enough studied. However, cases of cutaneous toxicity are quite rare and present certain difficulties for differential diagnosis and treatment. This article presents two cases of effective nivolumab treatment in patients with generalized BRAFwt and BRAFmut cutaneous melanoma. The first case is of interest due to the presence of brain metastases in the patient. Nivolumab therapy helped achieving complete regression of intracranial metastases with the long-term effect. The second case, in addition to effective treatment, demonstrates a rare manifestation of skin toxicity – vitiligo on the face and upper extremities.

Prevalence of dermatological toxicities in patients with melanoma undergoing immunotherapy: Systematic review and meta-analysis

Background Checkpoint inhibitors have revolutionized advanced melanoma care; however, their cutaneous side effects have not been definitively elucidated. Objective To identify the prevalence of cutaneous toxicity in patients with melanoma treated with immune checkpoint inhibitors as monotherapy and/or in combination with chemotherapy and/or radiotherapy. Materials and methods We performed a systematic review and meta-analysis, which encompassed both clinical trials and observational studies describing the dermatological toxicities in patients treated with immune checkpoint inhibitors. The protocol was registered in the International Prospective Register of Systematic Review under the number CRD42018091915. The searches were performed using the CINAHL, Cochrane CENTRAL, LILACS, LIVIVO, PubMed, Scopus, and Web of Science databases. The methodological quality of the studies was evaluated with the JBI Critical Appraisal Checklist for Studies Reporting Prevalence Data Results A total of 9,802 articles were identified in the databases. The final sample comprised 39 studies. The evaluated drugs were ipilimumab, tremelimumab, pembrolizumab, and nivolumab. The results suggest that the most prevalent side effect was grade 1 and 2 pruritus (24%), followed by grade 1 and 2 rash (21%) and grade 1 and 2 vitiligo (10%). Conclusion The most prevalent side effects in patients treated with checkpoint inhibitors are pruritus, rash, and vitiligo, and they are rated mostly as grades 1 and 2 adverse events. Remarkably, vitiligo is most commonly found in patients treated with PD-1 inhibitors.

Pharmacokinetics and tolerance of repeated oral administration of 5-fluorocytosine in healthy dogs

Background 5-fluorocytosine is a pyrimidine and a fluorinated cytosine analog mainly used as an antifungal agent. It is a precursor of 5-fluorouracil, which possesses anticancer properties. To reduce systemic toxicity of 5-fluorouracil during chemotherapy, 5- fluorocytosine can be used as a targeted anticancer agent. Expression of cytosine deaminase by a viral vector within a tumor allows targeted chemotherapy by converting 5-fluorocytosine into the cytotoxic chemotherapeutic agent 5-fluorouracil. However, little is known about the tolerance of 5-fluorocytosine in dogs after prolonged administration. Results In three healthy Beagle dogs receiving 100 mg/kg of 5-fluorocytosine twice daily for 14 days by oral route, non-compartmental pharmacokinetics revealed a terminal elimination half-life of 164.5 ± 22.5 min at day 1 and of 179.2 ± 11.5 min, after 7 days of administration. Clearance was significantly decreased between day 1 and day 7 with 0.386 ± 0.031 and 0.322 ± 0.027 ml/min/kg, respectively. Maximal plasma concentration values were below 100 µg/ml, which is considered within the therapeutic margin for human patients. 5-fluorouracil plasma concentration was below the limit of detection at all time points. The main adverse events consisted of depigmented, ulcerated, exudative, and crusty cutaneous lesions 10 to 13 days after beginning 5-fluorocytosine administration. The lesions were localized to the nasal planum, the lips, the eyelids, and the scrotum. Histological analyses were consistent with a cutaneous lupoid drug reaction. Complete healing was observed 15 to 21 days after cessation of 5-fluorocytosine. No biochemical or hematological adverse events were noticed. Conclusions Long term administration of 5-fluorocytosine was associated with cutaneous toxicity in healthy dogs. It suggests that pharmacotherapy should be adjusted to reduce the toxicity of 5-fluorocytosine in targeted chemotherapy.