Factors predicting recurrence and postrecurrence survival in completely resected thymic carcinoma.

BACKGROUND

There are few data on factors predicting recurrence of completely resected thymic carcinoma. This study analyzed prognosticators for recurrence and postrecurrence survival.

METHODS

Eighty-two patients with surgically treated thymic carcinoma were reviewed between June 1988 and March 2013, and 54 who underwent complete resection were enrolled. Sex, age, myasthenia gravis, tumor histologic classification, Masaoka staging, characteristics of locoregional invasion and recurrence, and the treatment for recurrence were collected. Continuous variables between groups were compared using Student's t test, and categorical variables were compared using the χ2 test, Fisher's exact test, or Spearman rank correlation. Survival analysis was performed using the Kaplan-Meier and log-rank test. Statistical significance was set at a probability value of less than 0.05.

RESULTS

A total of 54 patients underwent complete resection for thymic carcinoma, 21 of whom had recurrent diseases and 33 of whom remained disease-free. Patients without recurrent disease had a significantly better 5-year overall survival of 79% than 26% of those who had recurrent disease (p=0.000). Masaoka staging and tumor invasion of the superior vena cava were significantly associated with recurrence-free survival in the univariate analysis (p=0.047 and 0.019, respectively). In the multivariate analysis for survival, tumor invasion into the superior vena cava was the only prognostic variable for recurrence-free survival (p=0.047). Patients who underwent surgical intervention followed by chemotherapy for recurrent diseases had the best progression-free survival after recurrence (p=0.000).

CONCLUSIONS

Superior vena cava invasion as well as Masaoka staging was significantly associated with recurrence-free survival in patients with completely resected thymic carcinoma. In patients with recurrent disease, surgical resection should be attempted for localized disease because it might provide some benefit for progression-free survival.