Table 2.

Lesion characteristics and local control rate.

	Local control rate
Category (n)	1 year (%)	2 years (%)	5 years (%)	10 years (%)	P-value
All lesions (75)	93	78	70	68
Longest axisa, cm
< 4.3 (54)	94	84	75	75	0.03
≥ 4.3 (19)	89	61	52	42
Site
High stretch tension (24)	92	78	72	66	0.91
Low stretch tension (51)	94	79	68	68
Earlobe keloid
Yes (35)	100	86	76	76	0.13
No (40)	87	71	64	60
Etiologyb
Large scar (30)	93	87	78	73	0.30
Small scar (45)	93	72	63	63
Age of onset, years
≤ 29 (48)	92	77	66	66	0.29
≥ 30 (25)	96	88	83	76
Shape
Regular (36)	97	94	80	80	0.02
Irregular (37)	89	63	59	54
Pain or pruritus before treatment
Yes (44)	98	79	66	63	0.83
No (15)	80	66	66	66
History of previous surgery for the lesion
Yes (34)	100	94	83	83	0.03
No (36)	86	67	64	59
Total radiation dose
15 Gy (61) or 10 Gy (1)	94	77	69	66	0.64
20 Gy (13)	92	85	74	74
Interval day from surgery to RT, day
0 (35)	90	78	69	63	0.64
≥ 1c (40)	95	79	70	70
Tranilast prescription
Yes (62)	92	78	68	65	0.52
No (10)	100	78	78	78

RT = radiotherapy.

The total number of lesions in some categories may not be 75 due to lack of data.

^aThe cutoff value was determined as 4.3 cm, which was an approximation of the mean of the recurred lesions.

^bLarge scar includes surgical wound, while small scar includes piecing, insect bite, or acne. No lesion was derived from burns.

^cAmong the 40 lesions in this group, 38 lesions were treated with RT the next day of the surgical excision. One of the remaining two lesions received RT 6 days later and the other 10 days after surgery considering the patient’s circumstances.