Bystryn states the following: “that the absolute number of thick melanomas is not declining probably simply reflects that they represent a continually smaller proportion of a continually increasing number of melanomas, not that they are a different type of melanoma.” I do not agree with this assumption. First, from an epidemiologic point of view, this is highly unlikely. Indeed, according to Bystryn's suggestion, stability in the number of thick melanomas would then mean that the steady improvement in our ability to diagnose this cancer early would have exactly paralleled the actual increase in incidence over a period of 25 years. This is hardly conceivable.
Lipsker D. Increasing Ratio of Thin to Thick Melanoma Lesions: Pathogenesis and Early Detection of This Cancer—Reply. Arch Dermatol. 2007;143(6):799-816. doi:10.1001/archderm.143.6.804-b