Changing trends in mortality from malignant melanoma.

Five-year survival rates for both men and women treated at the melanoma clinics at St Vincent's Hospital and Sydney Hospital and at Royal Prince Alfred Hospital were found to have gradually improved over a 26-year time period. It is concluded that the improved survival rates do not result from changes in the sex ratio of the patients presenting for treatment, their age or the site distribution of their primary lesion. It is suggested that a change in the biological nature of malignant melanoma may have occurred over this time period. Such a change, if proven, would cast doubt on the value of investigations in which historical controls are used to monitor the effects of changes in therapy.