Table 1.

Patient characteristics and biopsy specimens

Case groupControl groupP
Total no. patients4897
Sex
    Male (%)27 (56.3)50 (51.5)
    Female (%)21 (43.7)47 (48.5)0.59
No. biopsies before SCC
    One2297
    More than one26
Total no. tissue specimens examined14497
    Non-SCC9697
    SCC48
Mean age at initial biopsy (SD)70.4 (10.4)57.1 (21.2)<0.001
Time from initial biopsy to SCC
        Mean years (SD)3.2 (2.9)
        Range (y)0.08-13