Thymic carcinoma: current staging does not predict prognosis.

BACKGROUND

Thymic carcinomas are currently staged by Masaoka classification, a staging system for thymomas. We retrospectively evaluated surgical patients with thymic carcinoma to determine prognostic factors and to evaluate the usefulness of Masaoka staging in this disease.

METHODS

Our computerized tumor registry yielded 118 patients with thymoma. Review of pathologic material revealed 43 cases of thymic carcinoma. Collection of data was by review of hospital and physician charts and telephone contact with patients. Analysis of prognostic factors was performed in patients undergoing complete resection by the method of Kaplan-Meier and Cox proportional hazards regression.

RESULTS

Between 1949 and 1993, 43 patients underwent surgery for thymic carcinoma. Overall survival was 65% at 5 years and 35% at 10 years. Overall recurrence was 65% at 5 years and 75% at 10 years. On univariate analysis, survival was not dependent on age, sex, tumor size, or Masaoka stage but was dependent on innominate vessel invasion. By multivariate analysis, survival was dependent only on innominate vessel invasion.

CONCLUSIONS

Patients with thymic carcinoma have a high rate of recurrence. Tumor invasion of the innominate vessels is associated with a particularly poor prognosis. Although Masaoka staging is useful in staging patients with thymoma, it does not appear to predict outcome for patients with thymic carcinoma.