Histologic Changes During Treatment With Vismodegib in Locally Advanced Basal Cell Carcinoma: A Series of 19 Cases.

BACKGROUND: There are no large series describing cutaneous histologic changes during treatment with vismodegib in locally advanced basal cell carcinoma (BCC). OBJECTIVE: To analyze histologic changes in skin biopsy specimens from patients with locally advanced BCC treated with vismodegib. METHODS: A descriptive, retrospective study of patients with locally advanced BCC treated with vismodegib between June 2012 and December 2017 at the Instituto Valenciano de Oncología, Spain. Nineteen patients were biopsied before and during the treatment with vismodegib, and we compared histologic changes observed. RESULTS: Seven patients (37%) achieved complete response, which was characterized by replacement of tumor stroma with a hyaline scar, lymphocytic inflammatory infiltrate, keratin formation, and infundibular cysts. Twelve patients (63%) achieved partial response; 5 showed no phenotypic changes, whereas 7 showed histologic changes; 5 cases showed metatypical differentiation; and 2 cases presented squamous differentiation. We observed no cases of squamous cell carcinoma arising at vismodegib treatment sites and no association between initial histologic subtype and clinical response. LIMITATIONS: Many biopsy specimens were obtained by punch biopsy and may not be representative of the full tumors. We studied histologic changes only in complete and partial responses. CONCLUSION: Vismodegib can induce histologic changes toward metatypical or squamous differentiation of BCC in patients with partial response. Keratinizing phenomena were frequent, both in partial and complete response groups.

Histologic Features Associated with Deep Invasion in Dermatofibrosarcoma Protuberans. / Estudio de los factores histológicos asociados a la infiltración en profundidad en el dermatofibrosarcoma protuberans.

BACKGROUND: Dermatofibrosarcoma protuberans (DFSP) is a rare, slow-growing cutaneous tumor that can invade the subcutaneous tissue, muscle tissue, and even bone. OBJECTIVE: To identify histologic features associated with greater depth of invasion, i.e., local aggressiveness, in DFSP. MATERIAL AND METHODS: We analyzed associations between histologic features of DFSP (e.g., type of subcutaneous invasion, histologic pattern, cell type, areas of fibrosarcoma) and the presence and absence of muscle fascia involvement. RESULTS: We studied 155 cases of DFSP. The following histologic characteristics were significantly associated with involvement of the muscle fascia: the presence of a sheetlike pattern, a high degree of cellular pleomorphism, and more than 1 mitotic figure. The tumor did not extend beyond the subcutaneous tissue in the majority of cases (62.6%), but there was involvement of the fascia or galea aponeurotica in 17 cases (11%) and of the muscle tissue in 36 cases (23.2%). CONCLUSIONS: Histologic patterns, degree of pleomorphism, and number of mitotic figures are important predictors of deep invasion (fascia or muscle) in DFSP; these layers can be involved in up to 30% of cases.

A 12-Day Course of Imiquimod 5% for the Treatment of Actinic Keratosis: Effectiveness and Local Reactions. / Tratamiento con imiquimod al 5% durante 12 días para las queratosis actínicas: estudio de la eficacia y la reacción local.

INTRODUCTION AND OBJECTIVES: Imiquimod is an excellent option for patients with actinic keratosis, although its use may be limited by the long course of treatment required (4 weeks) and the likelihood of local skin reactions. The objectives of the present study were to demonstrate the effectiveness of a 12-day course of imiquimod 5% for the treatment of actinic keratosis and to examine the association between treatment effectiveness and severity of local reactions. PATIENTS AND METHODS: We included patients with at least 8 actinic keratoses treated with imiquimod 5% cream for 12 consecutive days. Local reactions were classified as mild, moderate, or severe. The statistical analysis of the association between local reactions and clinical response was based on the Pearson χ2 test and the Spearman rank correlation test. RESULTS: Sixty-five patients completed the study. Complete response was recorded in 52.3% and partial response in 75.4%. We found a statistically significant association between severity of the local reaction and response to treatment in both the Pearson χ2 test and the Spearman rank correlation test. CONCLUSIONS: A 12-day course of imiquimod 5% proved effective for the treatment of actinic keratosis. Severity of local reactions during treatment was correlated with clinical response.

Experience With Vismodegib in the Treatment of Advanced Basal Cell Carcinoma at a Cancer Center. / Experiencia con vismodegib en carcinoma basocelular avanzado en un centro oncológico.

INTRODUCTION AND OBJECTIVES: Vismodegib is the first selective Hedgehog inhibitor approved for the treatment of locally advanced and metastatic basal cell carcinoma (BCC). In this article, we describe our experience with the use of this drug to treat advanced and/or multiple BCCs at a cancer center over 5 years. MATERIAL AND METHODS: We analyzed the following variables: patient age and sex; tumor location, size, type, and characteristics; time since onset; primary or recurrent status; duration of treatment; response to treatment (complete, partial, stabilization, or absence of response); adverse effects; and recurrences. RESULTS: We treated 22 patients, of whom 20 had locally advanced BCCs and 2 had metastatic BCCs with lymph node involvement. The treatment was administered over a mean of 11.8 months. Nine patients (41%) achieved complete response and 10 (45%) partial response. The disease was stabilized in 3 (14%). Two patients relapsed after a median of 21 months. The main adverse effects were dysgeusia, alopecia, and muscle cramps, all of which were mild. None of the patients developed squamous cell carcinoma in an area treated with vismodegib, although metatypical changes were observed after treatment. CONCLUSIONS: With a response rate of 96%, vismodegib is a safe and effective treatment for locally advanced BCC. Adverse effects are generally mild but they need to be taken into account owing to their high frequency.