Low-Dose Retinoids in the Prevention of Cutaneous Squamous Cell Carcinomas in Organ Transplant Recipients

Iatrogenic immunosuppression and cutaneous malignancy

Patients with autoimmune and inflammatory conditions often receive long-term immunosuppressive therapy. Some of the largest patient populations with iatrogenic immunosuppression include patients who have received solid-organ transplants or who have rheumatoid arthritis or psoriasis. Although treatments improve patient outcomes, individuals with immunosuppression subsequently may have an increased risk of skin cancer, including squamous cell carcinoma, basal cell carcinoma, and malignant melanoma.

Update on the management of high-risk squamous cell carcinoma

Cutaneous squamous cell carcinoma (CSCC) is the second most common malignancy occurring in white patients in the United States and incidence rates are increasing. While the majority of the 87,000-760,000 cases that occur yearly in the U.S. are curable, 4% develop lymph node metastases and 1.5% die from the disease. Given the frequency of occurrence of CSCC, it is estimated to cause as many deaths yearly as melanoma, with the majority occurring in patients with high risk tumors or in those at high risk for metastasis due to a variety of host factors, most commonly systemic immunosuppression. There are currently no standardized prognostic or treatment models to assist clinicians in most effectively identifying and managing these patients. Identification of patients at risk for poor outcomes as well as standardization regarding classification, staging, and treatment of high-risk tumors is critical for optimizing patient care. In this article, available literature on the classification and management of high risk CSCC is briefly summarized, emphasizing new information.

Skin cancer in solid organ transplant recipients: advances in therapy and management: part II. Management of skin cancer in solid organ transplant recipients

The management of skin cancer in solid organ transplant recipients is a challenge to both the dermatologist and transplant physician. Part II of this continuing medical education review offers an approach to the management of this increasing problem. The importance of specialty dermatology clinics providing access to transplant patients, frequent skin cancer screening, patient education, and multidisciplinary care is discussed. The management of low risk squamous cell carcinoma with topical therapies, photodynamic therapy, systemic retinoids, and capecitabine is reviewed. Revision of immunosuppression in the management of high-risk patients is discussed in association with the potential role of sentinel lymph node biopsy for aggressive disease. Finally, management of in-transit and metastatic squamous cell carcinoma is reviewed, with a discussion of the role of more recent innovative therapies, including epidermal growth factor receptor inhibitors in advanced squamous cell carcinoma in solid organ transplant recipients.

Malignancies following lung transplantation

Malignancy is an important complication of thoracic organ transplantation and is associated with significant morbidity and mortality. Lung transplant recipients are at greater risk for cancer than immunocompetent persons, with cancer-specific incidence rates up to 60-fold higher than the general population. The increased risk for cancer is attributed to neoplastic properties of immunosuppressive medications, oncogenic viruses, and cancer-specific risk factors. This article addresses the epidemiology, presentation, and treatment of the most common malignancies after lung transplantation, including skin cancer, posttransplant lymphoproliferative disorder, and bronchogenic carcinoma.

Acitretin induces apoptosis through CD95 signalling pathway in human cutaneous squamous cell carcinoma cell line SCL-1

Skin cancers are by far the most common human malignancies. Retinoids have shown promising preventive and therapeutic effects against a variety of human malignancies. The aim of this study was to investigate the apoptosis-inducing effect of acitretin on human skin squamous cell carcinoma (SCC) SCL-1 cells. We found that acitretin preferentially inhibited the growth of SCL-1 cells in a dose- and time-dependent manner, but not of non-malignant keratinocyte HaCaT cells. This inhibition appeared to be due to induction of apoptosis as revealed by enzyme-linked immunosorbent assay. AnnexinV/propidium iodide assay and morphological observation confirmed the pro-apoptotic effect of acitretin on SCL-1 cells. We further demonstrated that apoptosis was induced within 1-2 days and involved activation of caspases-8, -9, -3 and poly (ADP-ribose) polymerase (PARP). Caspase-8 inhibitor effectively suppressed acitretin-induced apoptosis whereas caspase-9 inhibitor did not. Acitretin increased the levels of CD95 (Fas), CD95-ligand and Fas-associated death domain. Neutralizing ZB4 anti-Fas antibody significantly inhibited the apoptosis in SCL-1 cells induced by acitretin. These results suggest that acitretin is able to induce apoptosis in skin cancer cells possibly via death receptor CD95 apoptosis pathway without affecting the viability of normal keratinocyte.

[Skin cancers after organ transplants]

Squamous cell carcinoma and basal cell carcinoma are the most common cancers after transplants, affecting more than half of all patients in the long term. In the 5 years after a first squamous cell carcinoma, 90 to 100% of transplant patients subsequently develop multiple skin carcinomas of various types and at least 20% develop noncutaneous cancers. Management of these patients requires, beyond the usual dermatologic treatments, a revision of their immunosuppression regimen to reduce the tumor risk. New immunosuppressants that inhibit the m-TOR protein (sirolimus and everolimus) appear to offer promising perspectives, and patients treated with these drugs from the time of their transplantation have fewer skin cancers than patients with the standard protocols. On the other hand, the benefit of prescribing them later after the transplant remains to be shown, because of the frequency of intolerance phenomena. Several prospective French multicenter studies are currently assessing the effect of replacing anticalcineurins by sirolimus or everolimus for secondary prevention of skin cancers in renal or cardiac transplant patients who have already developed skin cancer. Primary prevention requires that patients be educated about strict sun protection from the transplant onwards and have a routine annual dermatologic examination enabling early treatment of lesions.

Systemic retinoid therapy: a status report on optimal use and safety of long-term therapy

Systemic retinoids are an important component of the dermatology treatment armamentarium offering unique therapeutic properties, and are widely used to treat a large spectrum of skin disorders. Rational selection of candidates for treatment, knowledge regarding appropriate and optimal use, awareness of common and uncommon potential adverse reactions, and proper use of clinical and laboratory monitoring can result in effective and safe treatment of several severe skin disorders that impact poorly on the overall health and quality of life of affected patients.

Specialist dermatology clinics for organ transplant recipients significantly improve compliance with photoprotection and levels of skin cancer awareness

BACKGROUND

Organ transplant recipients (OTRs) have 100-fold increased risk of developing squamous cell carcinomas. Cumulative exposure to ultraviolet radiation is the main risk factor and there is evidence that lack of dermatological surveillance may be responsible for poor levels of knowledge and photoprotection among OTRs.

OBJECTIVES

This study evaluated whether routine consultation in a specialist OTR dermatology clinic improves understanding of skin cancer risk and compliance with photoprotection measures.

METHODS

A cross-sectional questionnaire-based study was performed in a specialist OTR dermatology clinic at Bart's and the London NHS Trust, London, U.K. The subjects were 399 white-skinned patients under surveillance in a renal transplant clinic, who were sent a postal questionnaire from the renal transplant clinic. The main outcome measures were responses to the questionnaire regarding photoprotective practices and skin cancer risk awareness.

RESULTS

Two hundred and ninety-two of 399 (73%) responded, of whom 89% had previously attended the specialist dermatology clinic. Ninety-six per cent recalled receiving photoprotection advice at least once (85% from dermatologists); 92% reported use of sunscreen; 88% specifically dressed to photoprotect themselves; 96% directly avoided sun exposure during summer; 68% were aware that an increased risk of skin cancer was the reason that extra photoprotective measures were important after a transplant. Photoprotective measures and level of skin cancer awareness were significantly lower in those responders who had never attended the specialist clinic. No obvious bias was identified among nonresponders.

CONCLUSIONS

Skin cancer awareness and compliance with photoprotective measures in our patient population is generally greater than previously reported, suggesting that delivery of educational messages regarding skin cancer may be improved if provided in a specialist dermatological setting.

Skin Cancer After Transplantation: A Guide for the General Surgeon

The success of organ transplantation has been accompanied by serious concerns regarding the incidence and management of potentially catastrophic cutaneous carcinogenesis in transplant recipients. Delivery of the highest quality of care requires a concerted effort toward collaboration between multiple surgical and medical specialties. The purpose of this review is to provide the general surgeon with a practical, user-friendly guide to the important components of comprehensive dermatologic care for organ transplant recipients (OTRs) with references to more detailed sources of information.

Skin cancer chemoprevention with systemic retinoids: an adjunct in the management of selected high-risk patients

Systemic retinoids (isotretinoin, etretinate, and acitretin) have been shown to be effective chemotherapeutic agents in studies of patients with xeroderma pigmentosum, the nevoid basal cell carcinoma syndrome, and recipients of organ or bone marrow transplantation. In addition, patients who do not have these disorders but who are actively developing large numbers of new skin cancers may also benefit from this approach. All patients developing large numbers of skin cancers need rigorous UV protection and frequent dermatologic examinations. Although isotretinoin and acitretin share overlapping toxicities, there are differences that may affect drug choice. Because low doses may be effective, there are advantages to beginning treatment at a low dose, and subsequently, increasing dose if necessary, based on patient response. Laboratory monitoring including pregnancy testing should be performed before and during treatment. Long-term toxicity, primarily involving the skeletal system, can be monitored with imaging studies.

Multiple verrucous carcinomas treated with acitretin

Cutaneous verrucous carcinoma is a rare variant of low-grade squamous cell carcinoma. It usually involves distal extremities and is often misdiagnosed as giant warts. Multiple cutaneous verrucous carcinomas are rare in the English-language literature. We describe a 41-year-old man with multiple verrucous plaques on both feet and ankles, as well as the left thigh. Immunohistochemical study with proliferating cell nuclear antigen revealed positive staining of the basal and suprabasal layers. The patient's condition was successfully treated with systemic acitretin.