Table 1. Cohort demographics in relation to whether the primary tumor was reported as being ulcerated or not.

Cases with no nodal primary were excluded.

	Total*	Cases with Ulcerated Tumors	Cases without Ulcerated Tumors	P value Testing Cases with/without Ulcerated Tumor
Age at Diagnosis				0.0001**
Median (range)	56 (17–90)	60 (22–90)	55 (17–85)
Gender				0.001***
Male	924 (43.0 %)	215 (50.5%)	699 (41.2%)
Female	1223 (57.0%)	211 (49.5%)	997 (58.8%)
Adjusted Vitamin D* (nmol/l)				0.09***
<20	109 (6%)	27 (8%)	82 (5.8%)
20–60	1172 (67%)	222 (66.7%)	942 (66.9%)
60–85	394 (22.4%)	74 (22%)	315 (22.3%)
85–100	55 (3%)	10 (3%)	44 (3.1%)
100+	26 (1.5%)	0 (0%)	25 (1.8%)
BMI (units)				0.06***
<18.5	17 (0.8%)	1 (0.2%)	16 (1%)
18.5–25	799 (37.8%)	140 (33.7%)	652 (38.9%)
25–30	854 (40.4%)	174 (41.8%)	670 (40.0%)
30+	446 (21%)	101 (24.3%)	338 (20.2%)
NSAIDs (BNF 10.1.1)				0.9***
Ever used	184 (8.6%)	36 (8.5%)	147 (8.7%)
Never used	1949 (91.4%)	387 (91.5%)	1539 (91.3%)
Aspirin				0.008***
Ever used	247 (12%)	65(15%)	181 (11%)
Never used	1886 (88%)	358 (85%)	1505 (89%)
Duration of aspirin use for users (years)				1**
Median (range)	4.7 (0.08–43.5)	4.7 (0.28–43.5)	4.7 (0.08–24.1)
Diabetes				0.002***
Yes	81 (4%)	27 (6.7%)	53 (3.3%)
No	1968 (96%)	376 (93.3%)	1570 (96.7%)
Ever smoked				0.04***
Yes	926 (45%)	202 (49.5%)	715 (43.8%)
No	1137 (55%)	206 (50.5%)	917 (56.2%)
Still smoke (yes/no)				0.2***
Yes	243 (11.8%)	55 (13.5%)	184 (11.3%)
No	1821 (88.2%)	354 (86.6%)	1448 (89.7%)
Duration smoked, excluding non smokers (years).				0.05**
Median (range)	20.9 (0.1–72)	23 (0.3–58.1)	20 (0.1–72)
Pack years (inc. rolls and cigars per 10 packyears)				0.02**
Median (range)	1.4 (0.003–188)	1.6 (0.05–10.7)	1.4 (0.003–188)

^*Including cases with missing ulceration status

^**P value calculated using a Mann Whitney U test

^***P value calculated using a chi squared test.