Imiquimod 5% cream in the treatment of superficial and nodular basal cell carcinomas: study of 10 cases

Cutaneous field cancerization: clinical, histopathological and therapeutic aspects

The concept of "field cancerization" was first introduced by Slaughter in 1953 when studying the presence of histologically abnormal tissue surrounding oral squamous cell carcinoma. It was proposed to explain the development of multiple primary tumors and locally recurrent cancer. Organ systems in which field cancerization has been described since then are: head and neck (oral cavity, oropharynx, and larynx), lung, vulva, esophagus, cervix, breast, skin, colon, and bladder. Recent molecular studies support the carcinogenesis model in which the development of a field with genetically altered cells plays a central role. An important clinical implication is that fields often remain after the surgery for the primary tumor and may lead to new cancers, designated presently as "a second primary tumor" or "local recurrence," depending on the exact site and time interval. In conclusion, the development of an expanding pre-neoplastic field appears to be a critical step in epithelial carcinogenesis with important clinical consequences. Diagnosis and treatment of epithelial cancers should not only be focused on the tumor but also on the field from which it developed. The most important etiopathogenetic, clinical, histopathological and therapeutic aspects of field cancerization are reviewed in this article.

Topical treatment of actinic keratosis with imiquimod 5% cream

The viability and the efficiency of imiquimod 5% cream in a cat which suffered from nasal actinic keratosis were evaluated. The procedures were carried out at home by the owners themselves. Six packets of the cream were used, one per week, in three consecutive daily applications, with a four-day interval (without treatment). The cytological results were negative for neoplastic cells 30 days after the end of the treatment. A clinical revision was conducted 18 months later and the animal showed no signs of recurrence. The cream proved to be safe and efficient. There are no reports regarding efficiency in animals concerning the treatment with imiquimod 5% cream and also regarding other effects related to this treatment. A case report presenting a positive response can reveal with terapeutical possibilities that it would be easily available and applicable for all professionals. In the future it would be a new alternative to avoid progressions of this kind of neoplasia which is often observed in the small animal clinic.

Treatment of cutaneous tumors with topical 5% imiquimod cream

INTRODUCTION

There are various approaches to the treatment of cutaneous tumors; one of them is treatment with imiquimod, a synthetic toll-like receptor agonist with a low molecular weight that offers a topical, noninvasive, and non-surgical therapeutic option. The main objective of our study was to provide data on 89 patients who used a 5% imiquimod cream for the treatment of cutaneous tumors at the Cutaneous Oncology Group of the Dermatology Department of Hospital das Clinicas from 2003 to 2008.

MATERIALS AND METHODS

Here, we present our experience in the treatment of 123 cutaneous tumors of various types, including basal cell carcinoma (BCC), squamous cell carcinoma (SCC), Bowen's disease, erythroplasia of Queyrat, Paget's disease, and trichoepithelioma, with 5% imiquimod cream from 2003 to 2008 in the Cutaneous Oncology Group of the Dermatology Department of Hospital das Clinicas. Patients were divided into two separate groups according to their diagnosis and comorbidities; these comorbidities included epidermodysplasia verruciformis, xeroderma pigmentosum, albinism, basal cell nevus syndrome, Brooke-Spiegler syndrome, HIV, chronic lymphocytic leukemia, B-cell lymphoma, and kidney transplantation. Treatment duration, response to imiquimod, follow-up, recurrence, and local and systemic reactions associated with use of the drug were analyzed. Epidemiological data were obtained and cure rates were calculated.

RESULTS

The ratio of women to men was 1.28:1, and the mean age was 63.1 years. Tumors were located mainly on the face, back, trunk, and legs. For patients with comorbidities, the overall cure rate was 38%. These specific patients demonstrated cure rates of 83.5% for superficial BCC and 50% for Bowen's disease. Aggressive BCC and superficial and nodular BCC did not present a good response to treatment. Trichoepitheliomas and nodular BCC showed a partial response, and erythroplasia of Queyrat showed a complete response. For patients without comorbidities, the overall cure rate was 73%. For these patients, the cure rates were 85.7% for superficial and nodular BCC, 88% for superficial BCC, 57% for Bowen's disease, 50% for nodular BCC, and 50% for aggressive BCC. One SCC lesion demonstrated a complete response, and tumors caused by Paget's disease and erythroplasia of Queyrat presented a partial response. None of the tumors considered as clinically cured recurred. Thirty-seven lesions demonstrated no response to imiquimod. Having a cutaneous comorbidity, high-risk tumors such as mixed aggressive BCC (sclerodermiform or micronodular), nodular BCC, or Bowen's disease, and presenting no local reaction to imiquimod were considered as risk factors for a worse prognosis. We demonstrate that patients with no response to imiquimod, even when they demonstrated no local reaction, can undergo another cycle of six weeks of imiquimod treatment and show a complete response. The healing pattern led to good cosmetic outcomes, and the side effects were tolerable.

CONCLUSIONS

Our experience confirms imiquimod as an effective treatment option for several types of cutaneous tumors, especially in patients without the cutaneous comorbidities cited above and with low-risk tumors. Imiquimod has a relatively low cost compared to other therapeutic options and can be delivered via ambulatory care to patients with surgery contraindications, and its side effects are tolerable.