Risk factors related to postoperative recurrence of dermatofibrosarcoma protuberans: A retrospective study and literature review

Table 1 Clinical characteristics of 44 patients with dermatofibrosarcoma protuberans

Factor	Total	Primary group	Recurrent group	P value
Sex				0.741
Male	21	9	12
Female	23	11	12
Onset age (mean ± SEM, yr)	31.82 ± 1.64	30.90 ± 2.34	32.58 ± 2.24	0.616
Duration (mean ± SEM, mo)	82.09 ± 12.19	54.50 ± 15.40	105.08 ± 16.63	0.037
Tumor diameter (mean ± SEM, cm)	3.61 ± 0.46	2.25 ± 0.36	4.75 ± 0.70	0.004
Location				0.540
Trunk	26	12	14
Other sites	18	10	8

SEM: Standard error of the mean.

Table 2 Detailed information of misdiagnosed patients with dermatofibrosarcoma protuberans

Characteristic	Total	No. of patients with recurrence	No. of patients without recurrence	Recurrence rate (%)	P value
With misdiagnosis history	25	17	8	68.00
Without misdiagnosis history	19	7	12	36.84
Total	44	24	20	54.55	0.04

Table 3 Recurrence details

Characteristic	No. of patients with recurrence	No. of patients without recurrence	Percentage (%)	P value
Sex				0.294
Male	1	21	6.67
Female	3	19	7.70
Onset age				0.130
< 50	3	38	7.89
≥ 50	1	2	3.33
Age at diagnosis				0.213
< 5 yr	1	23	4.17
≥ 5 yr	3	17	15.00
Tumor size				0.252
< 3 cm	1	22	4.35
≥ 3 cm	3	18	14.29
Location				0.773
Trunk	2	23	8.00
Other sites	2	17	10.52
Premier or recurrence				0.028
Premier	0	23	0
Recurrence	4	17	19.05
No. treatment				/
0	0	19	0
1	0	16	0
2	2	3	40
≥ 3	2	0	100

Table 4 Surgical characteristics of patients with dermatofibrosarcoma protuberans

Characteristic	No. of patients with recurrence	No. of patients without recurrence	P value
Resection margin			0.841
< 3 cm	2	17
≥ 3 cm	2	21
Unknown	0	2
Resection depth			0.120
Above the fascia layer	1	24
Below the muscular layer	3	13
Unknown	0	2

Table 5 Radiotherapy of patients with dermatofibrosarcoma protuberans

	Radiotherapy group	Without radiotherapy group	P value
No. of patients without recurrence	3	35
No. of patients with recurrence	2	2
Recurrence rate (%)	33.33	5.41	0.013