[Outcome of Nonsurgical Treatment for Locally Advanced Thymic Tumors].

Background: Surgical resection remains the mainstay of treatment for patients with early-staged thymic tumors, while chemotherapy is most commonly used in stage IV cases. As for locally advanced thymic tumors, especially those unsuitable for surgery, the optimal therapy is still controversial. Thus, we conducted this retrospective study by comparing three nonsurgical treatment modalities to find some clues.
Methods: Three treatment modalities were used in 42 patients from October 2000 to December 2010, including radiotherapy (RT) alone, sequential chemoradiation (SCRT) and concurrent chemoradiation (CCRT). Objective response rate (ORR), overall survival (OS) and toxicity of the three regimens were compared accordingly.
Results: The ORR in all 42 patients was 61.9%, and 5-year OS was 46%. The ORR of RT, SCRT and CCRT were 43.8%, 50% and 87.5%, respectively (RT vs SCRT, P=0.692; RT vs CCRT, P=0.009; SCRT vs CCRT, P=0.051). The 5-year OS of RT, SCRT and CCRT were 30%, 50% and 61.9%, respectively (RT vs SCRT, P=0.230; RT vs CCRT, P=0.011; SCRT vs CCRT, P=0.282). Eleven patients developed neutropenia of grade 3-4, with 7 in CCRT group and 4 in SCRT, respectively. Nine patients experienced esophagitis of grade 3 with 2 in RT, 3 in SCRT and 4 in CCRT. There were also two cases of grade 3 radiation induced pneumonitis in CCRT group. No life-threatening side effects were noted.
Conclusions: When used to treat locally advanced thymic tumors unsuitable for surgery, CCRT performed more favorably than RT alone or SCRT in both tumor response and long time survival, but probably with the increasing risk of pulmonary damage. CCRT may offer the best chance of disease control in the management of locally advanced disease.