. 2021 May 5;157(6):727–729. doi: 10.1001/jamadermatol.2021.1098

Table. Frequency and Source of Discrepancies in Tumor Stage Among Primary Cutaneous Melanomas Within SEER Registries, 2004-2017.

Years of diagnosis	No. of discrepancies for each supplementary staging variable							Total discrepancies by resulting stage change^a
Years of diagnosis	Breslow depth (SSF1)^b	Ulceration status (SSF2)^b	Presence of mitoses (SSF7)^b	Regional nodes positive^c	Clinical lymph node status (SSF3)^c	Other distant metastasis^d	SEER combined summary stage 2000^e	Not stage changing	Stage increase	Stage decrease
Introduction of AJCC 6th edition staging to SEER
2004	0	0	NA	20	4	0	129	13	118	22
2005	2	0	NA	12	7	0	107	12	101	15
2006	2	0	NA	12	8	0	111	12	110	11
2007	3	0	NA	15	6	0	106	9	105	16
2008	0	0	NA	25	13	0	111	16	109	24
2009	7	0	NA	25	22	0	115	30	109	30
Introduction of AJCC 7th edition staging to SEER
2010	29	356	355	20	28	0	118	23	121	762
2011	108	262	261	35	39	0	133	25	156	657
2012	134	217	217	60	91	0	243	51	304	607
2013	175	203	209	58	104	0	218	70	287	610
2014	131	170	175	61	113	0	240	103	282	505
2015	129	151	152	88	119	0	224	99	265	499
Introduction of UICC 7th edition staging to SEER
2016	0	105	713	72	38	3	202	0	811	322
2017	0	62	532	70	58	3	163	0	655	233
Totals	720	1526	2614	573	650	6	2220	463	3533	4313

Abbreviations: AJCC, American Joint Committee on Cancer; NA, not applicable; SEER, Surveillance, Epidemiology, and End Results Program; SSF, site-specific factor; UICC, Union for International Cancer Control.

^{^a}

Stage-changing discrepancies are those that result in an increase or decrease to the tumor stage listed (eg, stage IIIB T4aN1bM0 tumor with site-specific factor 3 coded as “nodes negative on pathologic examination” would imply decrease to stage II).

^{^b}

Mismatch with T (tumor) component of TNM cancer staging system.

^{^c}

Mismatch with N (node) component of TNM cancer staging system.

^{^d}

Mismatch with M (metastasis) component of TNM cancer staging system.

^{^e}

The SEER Combined Summary Stage 2000 variable allowed for comparison of all 3 TNM components because it incorporates distant nodes/sites involved, regional by nodes involved, regional by extension only, regional by nodes involved and extension, regional not otherwise specified, and localized only.