Recurrence Risk And Role Of Adjuvant Radiotherapy For Dermatofibrosarcoma Protuberans After Resection

Purpose: To evaluate the recurrent risk of Dermatofibrosarcoma protuberans(DFSP)after surgical resection, and analyze the necessity of postoperative adjuvant radiotherapy.Methods: We retrospectively analyzed 104 pathologically confirmed DFSP patients from 2003 to 2015 in our institution. Enhance labeled polymer system(ELPS) was applied in immunohistochemistry, and the primary antibodies included CD34, Des,S100 and SMA. All patients' pathological type was identified by hematoxylin-eosin(HE) staining. Statistical analyses were performed using the SPSS statistical software package version 20.0. Univariate analysis was performed using Chi-square test and multivariate analysis was performed using Logistic regression model, differences in P values of <0.05 were considered significant.Result: A total of 104 DFSP patients were enrolled in our study. The median follow-up time was 53.5 months(range from 13.87-149.70 mouths). Of all the patients, 97 cases still alive and 7cases were died. Three patients died from tumor and3 patients died from other causes. Distant metastasis were found in 4 patients.Univariate analysis, performed using Chi-square test, was used to evaluate the recurrent factors such as age, gender, history of recurrence, size of tumor, location of tumor, surgical method, margin, pathological type, situation of radiotherapy after local excision and situation of radiotherapy after wide excision. Univariate analysis showed that age( ? 2 = 5.828, P = 0.035), size of tumor( ? 2 =6.324, P = 0.040), surgical method(x~2 = 19.76, P = 0.010), margin(x~2 = 14.204, P = 0.002) and pathological type(x~2 = 17.206, P = 0.002) significantly affect the recurrence rate of patients with DFSP. Gender(x~2 = 0.010, P = 1.000), history of recurrence(x~2 = 6.218, P = 0.139),location of tumor( ? 2 = 3.289, P = 0.142), situation of radiotherapy after local excision(x~2 = 1.875, P = 0.242) and situation of radiotherapy after wide excision(x~2= 0.555, P = 1.000) have no statistical difference for the influence of postoperative recurrence in patients with DFSP.Multivariate analysis, performed using Logistic regression model, was used to evaluate age, size of tumor, surgical method, margin and pathological type. Multivariate analysis showed pathological type(P = 0.011) and margin(P = 0.014) were the independent factors for DFSP.Conclusion: Pathological type and margin were the independent factors for DFSP.Patients received adjuvant radiotherapy or not had no influence in postoperative recurrence rate after wide excision.Adjuvant radiotherapy has a tendency to reduce the postoperative recurrence rate after local excision.