Table 1.

Patient, tumor, and treatment characteristics between patients with primary GI melanoma and cutaneous melanoma, 1973-2016 (N=320,199)

		Cutaneous Melanoma (N=319,327)		All GI Melanoma (N=872)			Anorectal Melanoma (N=730)		Other GI Melanoma Sites (N=142)
		N	%	N	%	p-value*	N	%	N	%	p-value**
Age at diagnosis	18-49	102646	32.1	98	11.2	<.001	82	11.2	16	11.3	0.94
	50-69	134043	42.0	351	40.3		292	40.0	59	41.6
	70-100	82638	25.9	423	48.5		356	48.8	67	47.2
Sex	Female	142144	44.5	509	58.4	<.001	447	61.2	62	43.7	<.001
	Male	177183	55.5	363	41.6		283	38.8	80	56.3
Race	White	301336	94.4	736	84.4	<.001	610	83.6	126	88.7	0.12
	Non-White	17991	5.6	136	15.6		120	16.4	16	11.3
Married	Yes	164910	51.6	464	53.2	0.36	391	53.6	73	51.4	0.64
	No	154417	48.4	408	46.8		339	46.4	69	48.6
Year of diagnosis	1973-1987	26710	8.4	68	7.8	0.98	54	7.4	14	9.9	0.37
	1988-1994	23032	7.2	62	7.1		52	7.1	10	7.0
	1995-2001	47839	15.0	130	14.9		109	14.9	21	14.8
	2002-2008	93167	29.2	258	29.6		209	28.6	49	34.5
	2009-2016	128579	40.3	354	40.6		306	41.9	48	33.8
GI cancer sites	Esophagus	-	-	54	6.2	-	-	-	54	38.0	-
	Stomach	-	-	28	3.2		-	-	28	19.7
	Intestine	-	-	40	4.6		-	-	40	28.2
	Colon	-	-	20	2.3		-	-	20	14.1
	Rectum	-	-	295	33.8		295	40.4	-	-
	Anus	-	-	435	49.9		435	59.6	-	-
SEER Summary Stage (missing=16,817)	Localized	261025	86.2	263	36.4	<.001	226	37.5	37	30.8	0.001
	Regional	29376	9.7	202	27.9		179	29.7	23	19.2
	Distant	12258	4.1	258	35.7		198	32.8	60	50.0
Tumor Sizea (missing=52,318)	<2 mm/cm	229240	85.8	89	16.5	-	87	18.8	32b	40.5 b	<.001
	2-<5 mm/cm	26374	9.9	267	49.4		237	51.3
	>=5 mm/cm	11726	4.4	185	34.2		138	29.9	47	59.5
Treatment (year diagnosis ≥1988)	Local tumor excision only	238343	81.5	220	27.4	<.0001	217	32.1	53b	41.4b	<.0001
	Major surgery only	24819	8.5	186	23.1		136	20.1
	Radiation only	2320	0.8	55	6.8		44	6.5	11	8.6
	Chemotherapy only	1356	0.5	26	3.2		19	2.8	7	5.5
	Radiation & chemotherapy	1168	0.4	27	3.4		26	3.9	c	c
	Local excision & chemotherapy	2185	0.8	29	3.6		28	4.1	15b	11.7b
	Major surgery & chemotherapy	338	0.1	47	5.9		33	4.9
	Local excision & radiation	2405	0.8	47	5.9		47	7.0	c	c
	Major surgery & radiation	332	0.1	18	2.2		14	2.1	c	c
	Local excision & Radiation & Chemotherapy	554	0.2	20	2.5		25b	3.7b	c	c
	Major surgery & Radiation & Chemotherapy	79	0.0	8	1.0		28	4.1	c	c
	No Treatment	18718	6.4	121	15.1		87	12.9	34	26.6

^*p-value is between Cutaneous melanoma and all GI melanoma patients

^**p-value is between GI melanoma sites anorectal and other sites

^aTumor size is thickness in mm for cutaneous melanoma and size in cm for GI melanoma

^bTreatment categories had to be collapsed for the Other GI Melanoma Sites due to small numbers

^cTreatment categories had to be suppressed for the Other GI Melanoma Sites due to small numbers