Anti-Melanoma immunity and local regression of cutaneous metastases in melanoma patients treated with monobenzone and imiquimod; a phase 2 a trial.

Vitiligo development in melanoma patients during immunotherapy is a favorable prognostic sign and indicates breakage of tolerance against melanocytic/melanoma antigens. We investigated a novel immunotherapeutic approach of the skin-depigmenting compound monobenzone synergizing with imiquimod in inducing antimelanoma immunity and melanoma regression. Stage III-IV melanoma patients with non-resectable cutaneous melanoma metastases were treated with monobenzone and imiquimod (MI) therapy applied locally to cutaneous metastases and adjacent skin during 12 weeks, or longer. Twenty-one of 25 enrolled patients were evaluable for clinical assessment at 12 weeks. MI therapy was well-tolerated. Partial regression of cutaneous metastases was observed in 8 patients and stable disease in 1 patient, reaching the statistical endpoint of treatment efficacy. Continued treatment induced clinical response in 11 patients, including complete responses in three patients. Seven patients developed vitiligo-like depigmentation on areas of skin that were not treated with MI therapy, indicating a systemic effect of MI therapy. Melanoma-specific antibody responses were induced in 7 of 17 patients tested and melanoma-specific CD8+T-cell responses in 11 of 15 patients tested. These systemic immune responses were significantly increased during therapy as compared to baseline in responding patients. This study shows that MI therapy induces local and systemic anti-melanoma immunity and local regression of cutaneous metastases in 38% of patients, or 52% during prolonged therapy. This study provides proof-of-concept of MI therapy, a low-cost, broadly applicable and well-tolerated treatment for cutaneous melanoma metastases, attractive for further clinical investigation.

Merkel cell carcinoma of the head and neck: emphasizing the risk of undertreatment.

Merkel cell carcinoma (MCC) is a rare primary cutaneous neuroendocrine carcinoma. It occurs predominantly in the head and neck area and often behaves aggressively. In this single-institution retrospective observational cohort study, we describe the results of a treatment strategy that we developed over the past decades. Endpoints of this study were local, regional and distant control, disease-specific survival and overall survival. In total 47 patients with head and neck MCC, diagnosed in the Netherlands Cancer Institute-Antoni van Leeuwenhoek (NKI-AvL) between 1984 and 2012, were included in this study. Local tumor control was 82 % (95 % CI 71-95 %) at 5 years. Regional lymph node metastases were found at the moment of diagnosis in 13 cases (28 %). In the group of patients who were initially cN0, the 5-year regional control was 80 % (68-95 %). The 5-year metastasis-free interval probability was 80 % (68-94 %). The disease-specific survival (DSS) at 5 years was 70 % (56-86 %). An overall survival of 54 % (40-72 %) was found at 5-year follow-up and of 37 % (23-59 %) at 10-year follow-up. Univariable Cox regression analysis of many clinical and pathological variables did not identify any predictors for DSS. The MCC has a high propensity for locoregional and distant spread in the head and neck region. Undertreatment, especially of the lymph nodes in the neck, is a serious problem as regional (micro)metastasis are common even in T1 tumors. Future research will have to elucidate the role of the sentinel lymph node procedure versus the elective selective node dissection and standardized elective local and regional radiotherapy in the head and neck area.

Propionibacterium acnes and the pathogenesis of progressive macular hypomelanosis.

BACKGROUND: Progressive macular hypomelanosis is a common hypopigmentation mainly on the central parts of the trunk, predominantly in young adults, especially women. It is often mistaken for pityriasis versicolor and pityriasis alba. It occurs in all races and has been described in many parts of the world. We discovered follicular red fluorescence restricted to lesional skin. We suspected a relation with a porphyrin-producing bacteria residing in sebum of the pilosebaceous duct, and we therefore performed a study in 8 patients. Observation In all biopsy specimens taken from lesional skin of 8 women, we could demonstrate gram-positive bacteria in the pilosebaceous duct, and a mild perifollicular lymphocytic infiltrate was seen. In all but 1 patient, Propionibacterium acnes was yielded from cultured biopsy specimens taken from follicular lesional skin. Healthy follicular skin did not show bacteria in histological sections, and cultures did not yield anaerobic bacteria. CONCLUSIONS: There seems to be a relation between the presence of P acnes and the hypopigmented macules. We propose that a factor is produced by these strains of P acnes, which interfere with melanogenesis. Based on these observations, we are undertaking a clinical trial to find a treatment for this troubling, intractable disease.