Survival outcome after surgery in patients with thymoma distant recurrence.

OBJECTIVE: Aim of this study is to describe characteristics and survival outcome of patients who underwent surgical treatment for distant thymoma relapse according to the International Thymic Malignancy Interest Group definition(ITMIG).

METHODS: Data of patients affected by thymoma recurrence from 4 different Institution were collected and retrospectively reviewed.Patients with loco-regional metastases, who underwent non-surgical therapies and with incomplete data on follow-up were excluded.According to the ITMIG distant recurrence definition,patients with recurrence due to hematogenic localization were included. Clinical and pathological characteristics were described using descriptive statistics while survival outcome was calculated using Kaplan-Meier curves and Cox regression analysis.

RESULTS: The analysis was conducted on 40 patients.A single localization was present in 13 patients,the relapse was intrathoracic in 28(70%),involving the lung in 26cases. Liver was operated in 7 cases, while other kind of abdominal involvement was detected in 8 cases.Adjuvant treatment was administered in 22cases(55%). Five and 10 year OS resulted 67% and30%. Univariable analysis identified as significant favorable factor a low-grade histology(A,B1, B2):5YOS 92.3% vs53.3% in high-grade (B3-C)(p=0.035). Site of recurrence and number of localization did not influence the prognosis, while in patients with adjuvant therapy administration there were a survival advantage also if not statistically significant:5YOS 84.8%vs54.5% in patients without adjuvant therapy(p=0.101). Multivariable analysis confirmed as independent prognostic factor low grade histology:HR=0.176,95% CI 0.042-0.744,p=0.018.

CONCLUSIONS: Our study showed a good survival outcome in patients who underwent surgery for distant thymoma recurrence,independently from the number and site of the relapse localization. Patients with A,B1,B2 histology presented a significantly better survival than patients with B3-C.