  Commercially available clinical decision support systems (CDSSs) for skin
cancer have been designed for the detection of melanoma only. Correct use of
the systems requires expert knowledge, hampering their utility for nonexperts.
Furthermore, there are no systems to detect other common skin cancer types,
that is, nonmelanoma skin cancer (NMSC). As early diagnosis of skin cancer is
essential, there is a need for a CDSS that is applicable to all types of skin
lesions and is suitable for nonexperts. Nevus Doctor (ND) is a CDSS being
developed by the authors. We here investigate ND's ability to detect both
melanoma and NMSC and the opportunities for improvement. An independent test
set of dermoscopic images of 870 skin lesions, including 44 melanomas and 101
NMSCs, were analysed by ND. Its sensitivity to melanoma and NMSC was compared
to that of Mole Expert (ME), a commercially available CDSS, using the same set
of lesions. ND and ME had similar sensitivity to melanoma. For ND at 95 percent
melanoma sensitivity, the NMSC sensitivity was 100 percent, and the specificity
was 12 percent. The melanomas misclassified by ND at 95 percent sensitivity
were correctly classified by ME, and vice versa. ND is able to detect NMSC
without sacrificing melanoma sensitivity.
