The melanoma 'epidemic': lessons from prostate cancer.

The rise in malignant melanoma incidence has been termed "epidemic". Closer scrutiny of epidemiologic data suggests overdiagnosis as the true cause of the dramatic rise in melanoma incidence. In epidemiologic terms, "overdiagnosis" describes lesions that are histologically malignant but biologically benign. Overdiagnosis is not unique to melanoma screening but is prevalent in screening for cancers of other organs, including the thyroid and prostate glands.