The Journal of dermatologic surgery and oncology最新文献

Retinoids, the natural and synthetic analogs of vitamin A, and alpha-interferon have been used effectively in the treatment of certain cutaneous premalignancies and malignancies. Retinoids have shown impressive activity against premalignant disorders of the skin (actinic keratoses, keratoacanthoma, epidermodysplasia verruciformis) and of other epithelial sites (oral leukoplakia, cervical dysplasia). In established basal cell skin cancers, topical retinoid treatment has produced a complete response rate of 33%, and systemic retinoids have produced an objective response rate of 51%. In advanced squamous cell skin cancers, systemic retinoids have produced a response rate of over 70%. Intralesional alpha-interferon has produced impressive responses and systemic alpha-interferon has produced a 50% objective response rate in basal and squamous cell carcinoma. Retinoid therapy and alpha-interferon have produced modest overall results in melanoma, although striking individual responses have been reported. In cutaneous T-cell lymphoma, which is notably refractory to chemotherapy, retinoids and alpha-interferon have produced responses in 60%+ and 70%+ of cases, respectively. Retinoids and alpha-interferon, either alone or in combination, offer exciting prospects for primary and neoadjuvant therapy for advanced malignancy. Retinoids also show promise as relatively nontoxic preventive and adjuvant therapy. Researchers should focus on integrating these drugs with other biological response modifiers, differentiation agents, and cytotoxic drugs for treating advanced malignancy.

In order to determine if individuals with dysplastic nevi (DN) are relatively more sun-sensitive than controls who do not have DN, the sun-reactivity skin types (based on the Harvard classification) were determined in these two groups. Compared with controls, sun-sensitive types were significantly overrepresented in the DN group. This is consistent with the hypothesis that the fundamental defect in the dysplastic nevus syndrome is the genetically unstable melanocyte, which is susceptible to neoplastic transformation induced by sunlight.

Because of recent growth in the uses and production of certain chlorofluorocarbon compounds, the ozone layer is at risk of diminishing. The major effect of a decrease in ozone will be an increase in the amount of UV-B radiation in sunlight. Even a small increase in UV-B radiation will almost certainly affect human health. The most obvious effect of increased UV-B radiation will be an increase in the incidence of basal and squamous cell carcinomas. Other possible effects include a contribution to the development of cutaneous melanoma, ocular changes leading to the formation of cataracts, and immunologic perturbations.

Our understanding of the carcinogenic process as it relates to human skin cancer is growing rapidly. As this understanding increases, so will our ability to alter the process in a positive fashion. Presently, sun exposure is known to be the major carcinogen in human skin. The use of sunscreens is, and will continue to be, the most effective method of preventing human skin cancer. As these agents become more effective, especially against long-wave UV radiation, and as patients begin to use them more conscientiously, we should experience a decrease in skin cancer rates. In addition, a number of chemical agents are presently being investigated as anticarcinogens, especially in those patients who are at high risk for the development of skin cancers. A number of these hold promise as safe and effective chemopreventatives in reducing the morbidity and mortality of cancer in human skin.

Exposure of people to indoor ultraviolet (UV) radiation has vastly increased in the past one or two decades, mainly due to increased recreational exposure and partly as a result of therapy for skin disease. This trend will result in an increased incidence of skin cancer, but the magnitude of the increase is speculative at present because of a lack of information about the extent and nature of the recreational UV exposure.

The process of cancer metastasis is sequential and selective and contains stochastic elements. The growth of melanoma metastases represents the endpoint of many lethal events that few tumor cells can survive. Primary tumors consist of multiple subpopulations of cells with heterogeneous metastatic properties, and the outcome of metastasis depends on the interplay of metastatic tumor cells with various host factors. This viewpoint is more optimistic than that of metastasis as a random process. A selective biological process is regulated by the interaction of tumor cells with their host, and these complex interactions can now be studied and manipulated.

In accordance with the sunlight hypothesis for its etiology, the incidence of malignant melanoma generally increases with increasing proximity to the equator. There are exceptions to this pattern, prominent among which is the tendency for incidence to increase with increasing distance from the equator beyond latitude 50 degrees north in Europe. This anomaly is probably explicable in terms of climatic factors, geographic variation in skin pigmentation, and the sun-seeking behavior of those in the north. The incidence of malignant melanoma is increasing at about 5% a year in most white populations, while there is no consistent tendency for it to increase in black populations. This difference suggests that the increase is due to increasing sun exposure. Evidence from recent case-control studies is consistent with both intermittent intense exposure and total accumulated exposure to the sun causing an increase in risk of malignant melanoma. Reconciliation of these two different patterns of effect of sun exposure may lie in more careful measurement of sun exposure and analysis of exposure specific to the site at which each melanoma is observed to occur.

Pigmented Bowen's disease is rare. We report an unusual case of pigmented Bowen's disease of the ring finger, which clinically presented as a superficial, spreading melanoma. Records of 420 lesions of Bowen's disease were reviewed; 7 lesions (1.67%) were pigmented and all occurred outside the anogenital area. We conclude that Bowen's disease should be considered in the differential diagnosis of pigmented lesions.