Malignant Melanoma: Beyond the Basics

Skin Cancers in Organ Transplant Recipients

Long-term utilization of immunosuppression in organ transplant recipients (OTRs) leads to decreased immune-mediated tumor surveillance and development of malignant tumors. A delicate balance needs to be maintained in the intensity of immunosuppression to keep the risk of malignancy low without jeopardizing life-saving graft function. OTRs are prone to developing skin cancers that exhibit unique epidemiologic, pathophysiologic, and prognostic characteristics. In this review, we discuss the most commonly reported skin cancers in OTRs: squamous cell carcinoma (SCC), basal cell carcinoma (BCC), Kaposi sarcoma, Merkel cell carcinoma, and malignant melanoma (MM). Tumors in this high-risk population are aggressive and may respond poorly to standard therapies; however, new targeted therapies are promising. Checkpoint inhibitor antibodies have been used for treatment of cutaneous SCC, Merkel cell carcinoma, and MM; epidermal growth factor receptor inhibitors have been used for cutaneous SCC; hedgehog pathway inhibitors have been used for BCC; and BRAF and MEK inhibitors are being used increasingly in the management of MM. Guidelines for dermatologic screening are variable and primarily based on expert opinion. Prospective evidence-based trials by multidisciplinary groups are needed to better define surveillance schedules for pre- and posttransplant cutaneous malignancies.

Topotecan-loaded lipid nanoparticles as a viable tool for the topical treatment of skin cancers

OBJECTIVES

This work aimed to evaluate semisolid formulations containing topotecan (TPT) loaded nanostructured lipid carriers (NLC) for topical treatment of skin cancers, as TPT is effective against a variety of tumours. A formulation which increases TPT skin permeation would be extremely desirable.

METHODS

TPT-NLC were prepared and incorporated in hydrogels with hydroxyethyl cellulose and chitosan (TPT-NLC-HEC and TPT-NLC-Ch, respectively). Control formulations were obtained by dispersing TPT in HEC and Ch hydrogels (TPT-HEC and TPT-Ch).

KEY FINDINGS

TPT-NLC-HEC and TPT-NLC-Ch showed to maintain the drug and nanoparticle dispersions stable for up to 30 days. When nanoparticles were incorporated into gels, TPT release was significantly decreased (P < 0.05). Still, TPT-NLC-HEC increased 2.37 times permeation compared with TPT-HEC (11.9 and 5.0 μg/cm² , respectively). Cell culture experiments with B16F10 melanoma demonstrated that nanoencapsulation significantly increased TPT cytotoxicity (P < 0.05). TPT-NLC was more toxic than free TPT, with IC50 value of 5.74 μg/ml, whereas free TPT had an IC50 > 20 μg/ml. As skin permeated values of TPT from developed formulation (TPT-NLC) were superior to melanoma IC50, it can be extrapolated that chemotherapeutic permeated amounts may be sufficient for a therapeutic effect.

CONCLUSIONS

TPT-NLC-HEC may be a valuable tool for the topical treatment of skin cancers.

What's New in Eyelid Tumors

Eyelid malignancies represent between 5% and 10% of all skin cancers. Basal cell carcinoma is the most common, followed by squamous cell carcinoma, sebaceous cell carcinoma, Merkel cell carcinoma, and melanoma. The gold standard treatment for periocular epithelial malignancies is surgical excision. Given the constraints of the anatomy and function of the eyelids, excision with negative margins and reconstruction can be challenging. In cases of significant tissue invasion or metastasis, complete tumor removal may not be possible. This review examines the management of periocular skin cancer from diagnosis and staging, including the role of sentinel lymph node biopsy, to both surgical and nonsurgical treatment. The development of targeted drug therapy against specific genetic mutations in cutaneous malignancies has allowed for the treatment of specific cancer cells with less systemic toxicity than more traditional treatments.