Table 2.

Postoperative recurrence rates and hazard ratios in ARC-CLSTs among sub-stages

	Crude recurrence rate % [No.]	Hazard ratio [95% CI]
Stage I	P = 0.002	P < 0.001
CLST A [78]	3.8 [3]	1.00 [ref.]
B [23]	17.4 [4]	5.59 [1.25- 25.06]
C [66]	16.7 [11]	4.96 [1.38- 17.78]
D [20]	35.0 [7]	11.47 [2.96- 44.39]
Stage IA	P = 0.007	P < 0.001
CLST A [65]	3.1 [2]	1.00 [ref.]
B [12]	0.0 [0]	N.A.
C [45]	4.4 [2]	1.53 [0.22- 10.89]
D [8]	37.5 [3]	17.18 [2.82-104.69]
Stage IB	P = 0.191	P = 0.153
CLST A [13]	7.7 [1]	1.00 [ref.]
B [11]	36.4 [4]	7.45 [0.82- 67.44]
C [21]	42.9 [9]	7.82 [0.99- 61.94]
D [12]	33.3 [4]	5.77 [0.64- 51.67]

ARC-CLSTs, clusters based on architectural elements; No., number of cases; CLST, cluster; P, P value for crude reccyrrence rate and harad ratio are calculated by Fisher's exact test and and Log-rank test, respectively; CI, confidence interval; ref., reference; N.A., not available Squamous cell carcinomas were excluded from analysis.