title: Role of sun exposure in melanoma.
abstract: BACKGROUND
  Malignant melanoma is the third most common skin cancer in the United States. It is commonly thought that sun exposure is causative in these tumors. Recently, however, the significance of the role of sun exposure in melanoma has come into question. Some have suggested that other factors, such as genetics, play a larger role, and that sun protection may even be harmful.
  
  
  OBJECTIVE
  To investigate the role of sun exposure in melanoma etiology. An extensive review of basic science and clinical literature on this subject was conducted.
  
  
  RESULTS
  Although exceptions exist, sun exposure likely plays a large role in most melanomas. The pattern of this exposure, however, is not fully known, and controversy exists, especially in the use of sunscreens. Sun exposure may interact with genetic factors to cause melanomas, and sun protective measures appear to be prudent.
  
  
  CONCLUSIONS
  The cause of melanoma is probably variable and multifactorial. Sun exposure may play a primary or supporting role in most melanoma tumors.
authors: Department of Dermatology, USC Keck School of Medicine, Los Angeles, California, USA.
authors: Gil B
authors: GB
authors: Ivry
authors: Christina A
authors: CA
authors: Ogle
authors: Elisabeth K
authors: EK
authors: Shim