Tumour staging of oesophageal cancer in the Swedish Cancer Registry: A nationwide validation study

Figures & data

Figure 1. The TNM classification for oesophageal cancer, adapted from the Union International Contre le Cancer (UICC) 6th edition.

Figure 2. Flowchart describing the selection of the validation cohort of patients, operated for oesophageal cancer in Sweden. cTNM, clinically based TNM staging; pTNM, pathology based TNM staging.

Table I. Descriptive characteristics of the cohort of patients operated for oesophageal cancer in Sweden in 2006–2010.

	All patients Number (%)	pTNM^a Number (%)	cTNM^a Number (%)	TNM not specified^a Number (%)
Total	397 (100.0)	104 (26.2)	183 (46.1)	110 (27.7)
Sex
Men	312 (100)	86 (27.6)	136 (43.6)	90 (28.9)
Women	85 (100)	18 (21.2)	47 (55.3)	20 (23.5)
Age (years)
< 61	138 (100)	39 (28.3)	59 (42.8)	40 (29.0)
61–67	128 (100)	34 (26.6)	62 (48.4)	32 (25.0)
> 67	131 (100)	31 (23.7)	62 (47.3)	38 (29.0)
Year of resection
2006	78 (100)	5 (6.4)	7 (9.0)	66 (84.6)
2007	75 (100)	21 (28.0)	27 (36.0)	27 (36.0)
2008	57 (100)	19 (33.3)	34 (59.7)	4 (7.0)
2009	100 (100)	33 (33.0)	63 (63.0)	4 (4.0)
2010	87 (100)	26 (29.9)	52 (59.8)	9 (10.3)
Histological tumour type
Squamous cell carcinoma	163 (100)	40 (24.5)	74 (45.4)	49 (30.1)
Adenocarcinoma	212 (100)	52 (24.5)	105 (49.5)	55 (25.9)
Other	22 (100)	12 (54.6)	4 (18.2)	6 (27.3)
Hospital type
University	240 (100)	50 (20.8)	119 (49.6)	71 (29.6)
Non-university	157 (100)	54 (34.4)	64 (40.8)	39 (24.8)
Hospital volume (average per year)
1–8 oesophagectomies	102 (100)	33 (32.4)	42 (41.2)	27 (26.5)
9–16 oesophagectomies	157 (100)	41 (26.1)	75 (47.8)	41 (26.1)
16–21 oesophagectomies	138 (100)	30 (21.7)	66 (47.8)	42 (30.4)

cTNM, clinically based TNM staging; pTNM, pathology based TNM staging.

^aAs reported in the Cancer Registry.

Table II. Completeness and concordance of the tumour stage and TNM components between the Swedish Cancer Registry and a comparison clinical cohort of patients receiving resection for oesophageal cancer in 2006–2010, presented per TNM source specified in the Cancer Registry.

	Completeness, number (%)	Concordance, %	Expected concordance, %	Kappa	SE	p
pTNM^a (N = 104)
T	101 (97.1)	82.7	28.6	0.76	0.06	< 0.001
N	103 (99.0)	95.2	49.9	0.90	0.10	< 0.001
M	89 (85.6)	81.7	77.1	0.20	0.05	< 0.001
Stage	102 (98.1)	98.1	33.9	0.97	0.06	< 0.001
cTNM^a (N = 183)
T	169 (92.3)	31.7	26.3	0.07	0.04	0.029
N	175 (95.6)	59.6	48.4	0.21	0.07	0.001
M	174 (95.1)	88.5	86.0	0.18	0.05	< 0.001
Stage	180 (98.4)	98.4	29.3	0.98	0.05	< 0.001
TNM^a not specified (N = 110)
T	85 (77.3)	53.6	22.4	0.40	0.05	< 0.001
N	83 (75.5)	65.5	37.7	0.45	0.07	< 0.001
M	75 (68.2)	65.5	64.3	0.03	0.03	0.110
Stage	108 (98.2)	98.2	29.8	0.97	0.06	< 0.001
All TNM^a assessments (N = 397)
T	355 (89.4)	51.1	26.1	0.34	0.03	< 0.001
N	361 (90.9)	70.5	45.8	0.46	0.04	< 0.001
M	338 (85.1)	80.4	77.7	0.12	0.02	< 0.001
Stage	390 (98.2)	98.2	29.8	0.97	0.03	< 0.001

cTNM, clinically based TNM staging; pTNM, pathology based TNM staging; SE, standard error. ^aT was categorised in 4 groups (T0-1, T2, T3 or T4), N in 2 groups (N0 or N1), M in 2 groups (M0 or M1) and tumour stage in 4 groups (0-1, II, III, or IV).