Outdoor activities in childhood: a protective factor for cutaneous melanoma? Results of a case-control study in 271 matched pairs

Background A matched case-control study was performed in Munich, Germany, i n 1996-97 to evaluate the risk of cutaneous melanoma due to ultraviolet (UV ) exposure behaviour in Southern Bavaria, Germany. Objectives Patients with cutaneous melanoma and controls were investigated by two physicians using a standardized questionnaire to identify risk facto rs for the development of melanoma, such as professional and leisure sun ex posure behaviour. In each person, a total body examination was performed to detect benign skin alterations, phenotypic characteristics and precursor l esions for skin cancer. Patients/methods A total of 271 melanoma patients and 271 controls were ind ividually matched for residence. age and gender. A multiple conditional log istic regression analysis was performed. Results Of 56 factors. those risk factors with a strong effect on the devel opment of melanoma were: the existence of melanoma in first degree relative s, solar lentigo, actinic keratosis, actinic cheilitis, skin phototype, imm ediate skin reaction to UV light at the start of the outdoor season, sunbur n in childhood and sun exposure during holidays in sunny areas 20 years bef ore melanoma was diagnosed: outdoor activities in childhood were found to b e protective. Conclusions Sunburn in childhood and increased sun exposure during annual h olidays in sunny areas should be avoided. In contrast, outdoor activities i n childhood, including soccer and gardening, should be encouraged because t hey are associated with a lower risk of melanoma formation.