Managing melanoma in situ

Imiquimod as Local Immunotherapy in the Management of Premalignant Cutaneous Conditions and Skin Cancer

Cutaneous cancers are, by far, the most common malignant neoplasms of the human being. Due to the great array of clinical conditions, their worldwide increasing incidence and the steady ageing of the population, non-invasive treatments modalities that show a good clinical response, a proper benefit-risk ratio and cosmetic results are becoming increasingly important in the clinical setting. Imiquimod is a topically applied immunomodulator which is often used in the management of several premalignant and malignant cutaneous disorders. This article is a review of the current literature on its mechanism of action, pharmacokinetics, and therapeutical effects.

Drug-selected population in melanoma A2058 cells as melanoma stem-like cells retained angiogenic features - the potential roles of heparan-sulfate binding ANGPTL4 protein

Malignant cancer may contain highly heterogeneous populations of cells, including stem-like cells which were resistant to chemotherapy agents, radiation, mechanical stress, and immune surveillance. The characterization of these specific subpopulations might be critical to develop novel strategy to remove malignant tumors. We selected and enriched small population of human melanoma A2058 cells by repetitive selection cycles (selection, restoration, and amplification). These subpopulation of melanoma cells persisted the characteristics of slower cell proliferation, enhanced drug-resistance, elevated percentage of side population as analyzed by Hoechst33342 exclusion, in vitro sphere formation, and in vivo xenograft tumor formation by small amount of tumor cells. The selected populations would be melanoma stem-like cells with high expression of stem cell markers and altered kinase activation. Microarray and bioinformatics analysis highlighted the high expression of angiopoietin-like 4 protein in drug-selected melanoma stem-like cells. Further validation by specific shRNA demonstrated the role of angiopoietin-like 4 protein in drug-selected subpopulation associated with enhanced drug-resistance, sphere formation, reduced kinase activation, in vitro tube-forming ability correlated with heparan-sulfate proteoglycans. Our finding would be applicable to explore the mechanism of melanoma stemness and use angiopoietin-like 4 as potential biomarkers to identify melanoma stem-like cells.

Linguine technique for excision of lentigo maligna and poorly defined non-melanotic skin cancer - A case series

Accurately identifying the clinical margins of lesions such as lentigo maligna, lentigo maligna melanoma and other non-melanotic skin cancers can often be a clinical challenge. Irregular, poorly-defined peripheral margins accompanied by the presence of subclinical disease only detectable histologically can mean rates of incomplete excision are increased. We seek to highlight the use of the linguine technique for excision of lesions with poorly-defined peripheral margins. We describe in detail the step-by-step process for undertaking the technique, highlighting its advantages and disadvantages with a review of the related literature. We present three cases where the senior author has employed the linguine technique for the excision of lentigo maligna, lentigo maligna melanoma and extramammary Paget's disease.

Enhanced chemosensitization of anoikis-resistant melanoma cells through syndecan-2 upregulation upon anchorage independency

Syndecan family proteins are heparan sulfate proteoglycans, which involved in various cellular activities and associating with metastatic potential and chemosensitivity of tumor cells. Melanoma is one of malignant tumors with poor prognosis upon metastasis. Previously, we had shown that melanoma cells remained survived under cell detachment, which was similar to the initial steps of tumor metastasis. Downregulation of syndecan-1 and upregulation of syndecan-2 in melanoma A375 cells were observed by different suspension conditions. Specific gene alterations also increased melanoma malignancy under anchorage independency. Thus, we would like to investigate in further the role of specific gene alteration, so that it could be used to develop novel strategy to treat melanoma.

In this paper, we found that syndecan-2 expression level as well the kinase phosphorylation levels increased upon anchorage independency. The pathway to regulate syndecan-2 expression shifted from PKCα/β-dependent under adhesion into PKCδ-dependent under cell suspension. Manipulation of syndecan-2 expression showed that PI3K and ERK phosphorylation as well the migratory ability increased with increased syndecan-2 expression level. In addition, suspended melanoma cells were more sensitive to chemoagents, which correlated with syndecan-2 overexpression, PI3K and ERK activations, serum level, and the presence of glycosaminoglycans.

In conclusion, we showed upregulation of syndecan-2 in anoikis-resistant melanoma cells enhanced chemosensitivity through PI3K and ERK activation. This observation would support and refine the strategy of adjuvant chemotherapy to overcome metastatic melanoma.

Recurrent in situ melanoma successfully treated with ingenol mebutate

Background

Treatment options for melanoma in situ (MIS) include imiquimod, radiation therapy, cryotherapy, excisional and Mohs surgery. Ingenol mebutate is a new topical treatment option recognized for actinic keratosis. Although in vitro effectiveness has been demonstrated on melanoma cell lines, its therapeutic potential for in vivo melanomas is unknown.

Case Report

In 2011, a 91-year-old woman presented a thick melanoma of her cheek. The lateral sections revealed persisting in situ melanoma, which were again excised. She presented for follow-up and a recurrent MIS was evidenced centered on the previous scar. She refused further surgery and ingenol mebutate (0.015% gel) was administered on three consecutive days. One month later, a complete clinical resolution was observed. Histology and immunohistology revealed no residual MIS.

Conclusion

In this patient, ingenol mebutate was successful and well-tolerated as a topical, alternative therapy for MIS after failure of other treatment options.

Electronic supplementary material

The online version of this article (doi:10.1007/s13555-014-0051-4) contains supplementary material, which is available to authorized users.

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.

Melanoma in situ in a private practice setting 2005 through 2009: location, lesion size, lack of concern

BACKGROUND

Studies have shown that the incidence of melanoma in situ (MIS) is increasing significantly.

OBJECTIVE

This study analyzes selected clinical and demographic characteristics of MIS cases observed in private dermatology practices in the United States.

METHODS

This study collected 257 MIS cases from 4 private dermatology practices in the United States from January 2005 through December 2009, recording age, gender, anatomic location, lesion size, patient-reported change in lesion, and concern about lesion. Case totals for invasive melanoma during the same period were recorded.

RESULTS

The data collected showed a higher incidence of MIS in sun-exposed areas of older patients, especially men. The median age of patients at the time of MIS detection was 69 years. The most common site for MIS was the head-neck region. The number of MIS cases collected exceeded the number of invasive malignant melanoma cases during the study period, with an observed ratio of 1.35:1.

LIMITATIONS

For 136 patients, data were collected retrospectively for lesion size, location, gender, and age. For these patients, patient-reported change in lesion and concern about lesion were not collected. Patients often did not consent to a full body examination, therefore, it is possible that MIS lesions may have been missed in double-clothed areas.

CONCLUSION

Careful attention to pigmented lesions, even lesions less than 4 mm, on sun-exposed areas, including scalp, trunk, and feet, will facilitate earlier diagnosis of MIS. As only 30.4% of male patients and 50% of female patients had concern about these lesions, it still falls to the dermatologist to discover MIS.