Table 2. Patient characteristics in association with the SII.

		Discovery set				Validation set
		SII				SII
Variable	N	Mean	s.e.m.	Median	P-value	N	Mean	s.e.m.	Median	P-value
All patients	171	1664	144	1003	NA	181	1034	98	611	NA
Histology
Seminoma	31	1259	336	932	0.703	33	966	231	608	0.059
Non-seminoma	127	1686	166	971		148	1050	109	1437
N/A	13
Tumour primary
Primary testicular	143	1487	153	909	<0.001	179	1032	99	600	0.238
Extragonadal	28	2571	347	1627		2	1302	939	1302
IGCCCG risk group
Good	90	900	178	644	<0.001	146	744	93	534	<0.001
Intermediate	24	2163	345	1319		19	1440	258	739
Poor	57	2661	224	1991		16	3203	281	2961
Number of metastatic sites
0	8	530	647	467	<0.001	55	548	153	461	<0.001
1–2	103	1437	180	751		101	882	113	611
⩾3	60	2207	236	1610		25	2725	227	1785
Retroperitoneal LN metastases
Absent	25	1213	348	709	<0.001	60	718	159	467	<0.001
1–5 cm	53	760	239	585		63	767	155	496
>5 cm	93	2302	181	2256		55	1605	166	1019
N/A	0					3
Mediastinal LN metastases
Absent	126	1480	165	759	<0.001	163	861	95	569	<0.001
Present	45	2180	276	1571		18	2609	287	1461
Lung metastases
Absent	109	1447	178	753	<0.001	142	760	102	522	<0.001
Present	62	2046	236	1464		39	2035	195	1153
Liver
Absent	137	1412	154	794	<0.001	172	933	95	580	<0.001
Present	34	2683	310	2411		9	2980	417	3154
Non-pulmonary visceral metastases
Absent	125	1357	162	757	<0.001	173	950	96	583	<0.001
Present	46	2500	266	1921		8	2860	448	2952
S-stage
0	25	799	339	638	<0.001	82	614	126	495	<0.001
1	65	939	210	660		65	982	141	634
2	24	2163	346	1320		21	1416	248	743
3	57	2662	225	1991		13	3338	315	2768

Abbreviations: IGCCCG=International Germ Cell Cancer Collaborative Group; LN=lymph node; NA=not applicable; SII=systemic immune-inflammation index.