A lot of this so far is speculative and lacks important nuance. Many of the reports about this issue use mean/median melanoma thickness as an outcome which can be misleading for a scrutiny dependent cancer like melanoma. https://twitter.com/Medscape/status/1328191312718401536

During lockdowns less melanoma screening happens so by definition the number of melanomas diagnosed will decrease. The question is does this affect morbidity/mortality?

Melanoma screening leads to the diagnosis of more thin lesions, many of which may be overdiagnosed. Therefore, it should not be surprising that mean/median thickness changes between pre-post lockdown time periods. But does it matter?

Its possible that many of the indolent, thin tumors are just not being counted.

While I think we must monitory this important issue closely, I hope we can agree the problem is way more complicated than measuring mean/median Breslow thickness or surveying dermatologists about their experience.

We need to examine hard endpoints like mortality, but we probably won't have those data for 1-2 years. I understand that we are doing what we can now, but we should accept the fact that this is all highly uncertain.

Finally, can somebody tell me what the difference between "real world" and "observational data"? And is one inherently better than the other?