Basal cell carcinoma (BCC) incidence rate is one the rise in Europe. Cancer registries were once the primary method to collect prevalence rates and population details. Due to an increase in multiple BCCs in patients, histological data has become significant. Also, treatment strategies vary from standard surgery to non-invasive methods. This study investigates BCC diagnosis and treatment choices without histological details.

EPIDERM project conducted an audit in 4 European countries (Netherlands, Scotland, Finland, and Malta) in different timeframes. Patients with one or more BCCs were retrospectively and prospectively studied. Clinical diagnosis and treatment choices underwent investigation. Electronic patient records and hospital pathology databases helped to confirm histological evidence.

About 1089 Netherland patients with first histology developed 1974 BCCs. Of these, 1833 or 92.9% had histological confirmation, while 141 or 7.1% were not. In Scotland, 294 patients with 344 BCCs were the subjects. About 306 or 89% were histological confirmed, while 38 or 11% were not. Here, a 3-month prospective study identified 44 patients with 58 BCCs. About 44 or 75.9% were histology confirmed, while 14 or 24.1% were not. In Finland, 701 patients had 977 BCCs, of which 807 were histological, while 170 were not. In Malta, with 420 patients having 477 BCCs, only 3 or 0.7% were histologically confirmed. Netherlands and Scotland patients prefer cryotherapy without histology. While in Scotland, 5% imiquimod cream was the preferred treatment.

The clinically diagnosed BCCs without histology differed in countries in the 0.7% to 24.1% range. The study confirms an underestimation of BCC burden based on pathology and cancer registries.