Two thousand eight hundred fifty-one SCC antigen assays were performed from 384 patients. An elevated pretreatment SCC level was associated with poorer cumulative survival over time (P<0.05). Fifty-five patients had recurrences, with 10 local and 45 distant recurrences. SCC levels were elevated in 47 patients (85%). The median lead time was 7.8 months. The cost of finding 1 recurrence was US$4750