Achromic superficial spreading melanoma accidentally treated with imiquimod

TLR7 agonist in combination with Salmonella as an effective antimelanoma immunotherapy

AIM

We evaluated a novel approach combining the use of attenuated Salmonella immunotherapy with a Toll-like receptor agonist, imiquimod, in B16F1 melanoma-bearing mice.

MATERIALS & METHODS

B16F1 melanoma-bearing mice were daily treated with topical imiquimod in combination with one intratumoral injection of attenuated Salmonella enterica serovar Typhimurium LVR01.

RESULTS

The combined therapy resulted in retarded tumor growth and prolonged survival. Combination treatment led to an enhancement in the expression of pro-inflammatory cytokines and chemokines in the tumor microenvironment, with a Th1-skewed profile, resulting in a broad antitumor response. The induced immunity was effective in controlling the occurrence of metastasis.

CONCLUSION

Salmonella LVR01 immunotherapy in combination with imiquimod is a novel approach that could be considered as an effective antimelanoma therapy.

Toll-like receptors and cutaneous melanoma

Innate immune cells recognize highly conserved pathogen-associated molecular patterns (PAMPs) via pattern recognition receptors (PRRs). Previous studies have demonstrated that PRRs also recognize endogenous molecules, termed damage-associated molecular patterns (DAMPs) that are derived from damaged cells. PRRs include Toll-like receptors (TLRs), scavenger receptors, C-type lectin receptors and nucleotide oligomerization domain-like receptors. To date, 10 TLRs have been identified in humans and each receptor responds to a different ligand. The recognition of PAMPS or DAMPs by TLRs leads to the activation of signaling pathways and cellular responses with subsequent pro-inflammatory cytokine release, phagocytosis and antigen presentation. In the human skin, TLRs are expressed by keratinocytes and melanocytes: The main cells from which skin cancers arise. TLRs 1-6 and 9 are expressed in keratinocytes, while TLRs 2-5, 7, 9 and 10 have been identified in melanocytes. It is hypothesized that TLRs may present a target for melanoma therapies. In this review, the involvement of TLRs in the pathogenesis and treatment of melanoma was discussed.

Learning from mistakes: errors in approaches to melanoma and the urgent need for updated national guidelines

BACKGROUND

The tracking and identification of errors in the detection and follow-up of melanoma are important because there is huge potential to increase awareness about the most vulnerable aspects of diagnosis and treatment, and to improve both from the perspective of healthcare economics. The present study was designed to identify where errors occur and to propose a minimum set of rules for the routine guidance of any specialist in melanoma management.

METHODS

This report describes the evaluation of a unique series of 33 cases in which errors applying to many steps in the diagnosis and treatment of melanoma were detected. Cases were collected at two centers in Romania, one public and one private, as part of a process of obtaining patient-requested second opinions.

RESULTS

A total of 166 errors were identified across the 33 patients, most of which were treatment errors. The errors fell into six categories: clinical diagnostic errors (36 errors among 30 patients); primary surgical errors (31 errors among 16 patients); pathology errors (24 errors among 17 patients); sentinel lymph node biopsy errors (13 errors among 13 patients); staging errors (17 errors among 13 patients); and treatment or management errors (45 errors among 33 patients).

CONCLUSIONS

Based on the present results, we propose that in countries lacking national guidelines, clinicians should adhere to international evidence-based guidelines for the diagnosis and treatment of melanoma.

Microinvasive melanoma: cutaneous pharmacotherapeutic approaches

Surgical excision is the treatment of choice for primary melanomas and radiation therapy is the accepted alternative for the subset of lesions not amenable to surgery. With the recent rise in melanoma incidence, especially in the elderly, there are a growing number of cases that are neither amenable to surgery nor radiation therapy. In this article, we review pharmacotherapeutic approaches to microinvasive melanoma (invasive radial growth phase melanoma) that might be considered in such circumstances. There are no approved drugs for the treatment of primary melanoma and randomized controlled trials with 5 or more years of follow-up have not been performed. The limited studies and numerous case series in the literature on pharmacologic treatment of primary melanoma have focused on topical therapies. Accordingly, we provide a review of the potential pharmacotherapeutic agents in the treatment of microinvasive melanoma by extrapolating from the available limited literature on the use of fluorouracil, azelaic acid, retinoic acid derivatives, interferon (IFN)-α, imiquimod, and other agents for melanoma in situ, invasive melanoma, and epidermotropic melanoma metastases. Our review indicates that topical fluorouracil and tretinoin are not effective as single agents. The efficacy of azelaic acid, tazarotene, cidofovir, and intralesional IFN-α, interleukin-2, and IFN-β is undefined. Imiquimod is the most studied and promising agent; however, optimal dosage, therapeutic regimen, and survival rates are unknown. In the face of a growing demand for non-surgical treatments, formal clinical trials are needed to ascertain the role of pharmacotherapeutic agents in the treatment of microinvasive melanoma.

Melanoma in situ treated successfully using imiquimod after nonclearance with surgery: review of the literature

BACKGROUND

The standard of care for melanoma in situ (MIS) is surgical removal by surgical excision with a 5-mm margin or Mohs micrographic surgery, but as more and more MIS is diagnosed in the head and neck region, surgeries may not be an option for patients when the lesions are large or less well defined. In addition, when negative margins cannot be achieved without grossly disfiguring the patient or when patients have medical comorbidities that preclude a surgical option, other treatment modalities may be considered. Recently, topical treatment with an immunomodulator, imiquimod, has been proposed as an alternative treatment for MIS.

OBJECTIVE

We report a case of MIS successfully treated with topical imiquimod cream. In addition, because there has not been any comprehensive review of the use of topical imiquimod on melanoma and MIS, we conducted an extensive literature search and reviewed the topic in detail.

MATERIALS AND METHODS

Using the keywords "imiquimod," "melanoma," "melanoma-in-situ," and "lentigo maligna," we searched the literature using PubMed in an attempt to find all relevant articles on the use of imiquimod on MIS or melanoma.

RESULTS

There were 46 reports involving 264 patients on the use of imiquimod on MIS or lentigo maligna. Twenty-three reports were published on the use of imiquimod on metastatic melanoma involving 55 patients, and two articles were on melanoma, with two patients in total. In addition, there were two articles on the use of imiquimod on dysplastic or atypical nevi with a total of 13 subjects.

CONCLUSION

Imiquimod appears to be beneficial in the treatment of MIS and melanoma metastases when surgical options are not feasible. Imiquimod should not be used for removal of dysplastic or atypical nevi. The treatment regimens varied from study to study, and there are no randomized controlled trials in the literature. More studies are needed to develop a reliable and reproducible treatment regimen, to fully elucidate the role of imiquimod in the treatment of MIS and melanoma, and to determine the prognostic predictors for favorable responses to imiquimod.