Findings demonstrate a suboptimal diagnosis of keratinocyte carcinoma during the COVID-19 pandemic, because of diagnostic delays probably consequent to both patient and health system related delay. Further studies will require to ascertain the impacts of these diagnostic delays on outcomes.

• Using data from the Netherlands Cancer Registry, experts assessed the effect of COVID-19 pandemic on trends in diagnoses of keratinocyte carcinoma (cutaneous squamous cell carcinoma (cSCC), basal cell carcinoma (BCC)) and evaluated the magnitude of diagnostic delays.

• A substantial reduction in the number of cSCC and BCC diagnoses was evident than the number of diagnoses expected during March to May 2020 (cSCC -29%, BCC -50%).

• Such reductions were seen across all age groups, both genders, and all regions.

• There was a higher than expected number of cSCC and BCC diagnoses in June to September, thereafter it slightly dropped below expected in October to December.

• Overall, 2020 keratinocyte carcinoma diagnoses continued to trail those expected, with a backlog of approximately 1,150 cSCCs and 11,767 BCCs remaining at the end of the year.