To determine whether FGFR1 overexpression is associated with progression of HN tumours to the CR state as defined by the time to biochemical relapse (persistent and significant rise in serum PSA levels), Kaplan–Meier graphs for tumours expressing low (below median) and high (above median) levels of FGFR1 were plotted and compared using the log-rank test. This evidence concerns the gene KLK3 and neoplasm.