UVB: susceptibility in malignant melanoma.

BACKGROUND It is well established that UV radiation provokes an immunological depletion in the skin, enabling the development of malignant cutaneous tumors. Most nonmelanoma skin cancer patients are considered to be UVB-susceptible. OBJECTIVE To study the behavior of UVB- susceptibility in malignant melanoma (MM) patients and whether this is a risk factor to the development of MM. METHODS Eighty-eight volunteers were selected and divided into two groups: healthy control group (n = 61) and MM group (n = 27), which were identified according to the following clinical criteria: histopathological type, level of invasion, skin phototype, sex and age. Susceptibility to ultraviolet B (UVB) radiation was measured by the onset of a contact hypersensitivity reaction to diphenylcyclopropenone among individuals sensitized in previously irradiated areas. RESULTS Susceptibility to UVB radiation was 81.5 in the MM group and 31.2% in the control group. The risk of an UVB-susceptible individual to develop MM was 9.7 times higher than when UVB resistant. CONCLUSION UVB susceptibility should be considered an important risk factor to the development of this type of cancer.