This could be due to increased diagnoses and treatment of benign lesions as Stage 1 melanomas — the 5-year survival rate of which is 92-97%.
The Austrian Tribune reports:
According to the recent revelations made by Cancer Research UK, it has been unveiled that a significant improvement has been noticed in the survival rate of people suffering from malignant melanoma.
It has now been found that more than 80% people diagnosed with malignant melanoma now have chances to survive the cancer. Cancer Research UK scientists were of the view that if situation of early 1970s is compared with present scenario then a drastic change will be noticed.
At that time, there were either more or less than 50% chances of survival. However, now things have changed. Due to the improved diagnosis rate, better treatment and increased awareness level, survival rate has improved.
There would be a real epidemiology problem — borderline misconduct — if basal and squamous carcinomas or benign lesions were being labeled Stage 1 melanoma and counted into the survival rates. It would push up the diagnostic rate at the same time. Is that what I understood your lede to say?