Table 1.

Demographics, clinical characteristics of patients aged >50 with advanced melanoma.

Variable	Whole population		Training cohort		Validation cohort		P value
	n	%	n	%	n	%
	5166		3614		1552
Age	0
50-60	1696	32.83%	1183	32.73%	513	33.05%	0.372
60-75	2540	49.17%	1795	49.67%	745	48.00%
>75	930	18.00%	636	17.60%	294	18.94%
Race
Black	68	1.32%	55	1.52%	13	0.84%	0.124
White	4990	96.59%	3477	96.21%	1513	97.49%
Other	108	2.09%	82	2.27%	26	1.68%
Sex
F	1743	33.74%	1226	33.92%	517	33.31%	0.591
M	3423	66.26%	2388	66.08%	1035	66.68%
Thickness
0-1	1102	21.33%	778	21.53%	324	20.88%	0.633
1-2	1214	23.50%	860	23.80%	354	22.81%
2-4	1452	28.11%	1000	27.67%	452	29.12%
>4	1398	27.06%	976	27.01%	422	27.19%
Ulceration
Yes	2631	50.93%	1828	50.58%	803	51.74%	0.482
No	2535	49.07%	1786	49.42%	749	48.26%
Number
1	4435	85.85%	3100	85.78%	1335	86.02%	0.752
>1	731	14.15%	514	14.22%	217	13.98%
Stage_M
No	4756	92.06%	3328	92.09%	1428	92.01%	0.891
Yes	410	7.94%	286	7.91%	124	7.99%
Stage_N
N1	3033	58.71%	2136	59.10%	897	57.80%	0.532
N2	1388	26.87%	960	26.56%	428	27.58%
N3	745	14.42%	518	14.33%	227	14.63%
Location
Head and face	832	16.11%	578	15.99%	254	16.37%	0.704
Trunk	1804	34.92%	1279	35.39%	525	33.83%
Upper limb and shoulder	1124	21.76%	768	21.25%	356	22.94%
Lower limb and hip	1276	24.70%	896	24.79%	380	24.48%
Others	130	2.52%	93	2.57%	37	2.38%
AJCC Stages a
III	4362	84.44%	3047	84.31%	1315	84.73%	0.622
IV	804	15.56%	567	15.69%	237	15.27%
Chemotherapy
Yes	479	9.27%	344	9.52%	135	8.70%	0.411
No	4687	90.73%	3270	90.48%	1417	91.30%
Surgery
No	1395	27.00%	988	27.34%	407	26.22%	0.383
Yes	3771	73.00%	2626	72.66%	1145	73.78%

^aAJCC Stages: The eighth edition American Joint Committee on Cancer (AJCC) TNM staging system.