Guarding against nonmelanoma skin cancer in solid organ transplant recipients
Periodic skin examination and ongoing counseling are central in your posttransplantation care of these patients at high risk of skin malignancy.
PRACTICE RECOMMENDATIONS
› Conduct a full-body skin examination at least once annually for solid organ transplant recipients. C
› Encourage daily use of broad-spectrum SPF ≥ 30 sunscreen and sun-protective clothing (long sleeves, pants, wide-brimmed hats) for these patients. A
› Consider chemoprophylactic agents for patients at especially high risk of nonmelanoma skin cancer. A
› Treat nonmelanoma skin cancer in a solid organ transplant recipient aggressively because of their increased risk of recurrence, local invasion, and metastasis. B
Strength of recommendation (SOR)
A Good-quality patient-oriented evidence
B Inconsistent or limited-quality patient-oriented evidence
C Consensus, usual practice, opinion, disease-oriented evidence, case series
Topical chemoprophylaxis
Topical medications used for cSCC chemoprophylaxis include 5-fluorouracil (5-FU), photodynamic therapy (PDT), imiquimod, ingenol mebutate, topical retinoids, and diclofenac.27 (See TABLE 2.27-40) Of these, the latter 3 are used less commonly because of the small packaging size of ingenol mebutate and the relative lack of efficacy data for topical retinoids and diclofenac.27 Imiquimod is often avoided when treating large surface areas because of the risk of systemic adverse effects associated with cytokine release.27
5-FU is US Food and Drug Administration (FDA)-approved for the treatment of AKs, and is used off-label for treating cSCC in situ (Bowen disease). It is the most commonly used topical therapy for field disease.27-29 5-FU is typically applied once or twice daily for 3 to 4 weeks. Common adverse effects include transient skin irritation and erythema.27
PDT involves topical application of a photosensitizer, such as 5-aminolevulinic acid or methyl aminolevulinate, followed by exposure to a visible light source, leading to antitumor effects on gene expression and destruction of proliferating cells through production of reactive oxygen species.30,31 Evidence is sufficient to support routine use of PDT for AKs and Bowen disease.30 A mild sunburn-like reaction is common following PDT, with transient erythema and discomfort typically lasting 1 to 2 weeks but not typically necessitating analgesic therapy.27
Imiquimod is a ligand that binds to and activates Toll-like receptor 7, leading to enhancement of the cell-mediated antitumor immune response and resultant tissue-specific apoptosis coordinated by type 1 T-helper lymphocytes.32 Topical imiquimod cream is FDA approved for field treatment of AKs at 2.5%, 3.75%, and 5% concentrations; efficacy has been demonstrated in the SOTR population.33,41 Multiple studies in immunocompetent patients have suggested that imiquimod might be slightly less efficacious than 5-FU.42-44
The tolerability of field treatment with imiquimod has been called into question.27 However, in a 2019 study comparing adverse reactions among 513 immunocompetent patients with field disease who were treated with either 5-FU 5% cream; imiquimod 5% cream; PDT with methyl aminolevulinate; or ingenol mebutate 0.015% gel, a similar or smaller percentage of patients treated with imiquimod reported moderate-to-severe itching, moderate-to-severe pain, and any adverse events, compared to patients treated with the other options.44
Continue to: Diclofenac
