Association of tumour size with clinical stages (CS). Box plot showing the associations of tumour size with CS. Each box represents one particular subgroup of the patient population. Horizontal line within box denotes median tumour size; upper and lower limits of boxes denote interquartile ranges (IQRs). Whiskers show lowest and highest values within a range of 1.5 IQR. Stars within boxes denote mean values of tumour size in the corresponding subgroups. The plot illustrates the markedly higher tumour sizes in patients with CS > CS1. This finding is almost identical in all groups examined: entire group of germ cell tumours (GCT), seminomas and nonseminomas.