Comparison of patterns of relapse in thymic carcinoma and thymoma

Abstract

Objective Thymic carcinomas (TC) are considered to be more aggressive than thymomas and carry a worse prognosis. We reviewed our recent experience with the surgical management of thymic tumors and compared the outcomes and patterns of relapse between TC and thymoma. Methods Single institution retrospective cohort study. Data included patient demographics, stage, treatment, pathologic findings, and postoperative outcomes. Results During the period 1995–2006, 120 patients with thymic tumors underwent surgery, including 23 patients with TC and 97 patients with thymoma by the WHO 2004 histologic classification. The overall 5 year survival was significantly different between TC and thymoma (TC 53%, thymoma 89%, p=0.01). Data on relapse was available for 112 patients. The progression-free 5 year survival was also significantly different between TC and thymoma (TC 36%, thymoma 75%, p<0.01). By multivariate analysis, thymic carcinoma and incomplete resection were found to be independent predictors of progression-free survival. Relapses in TC tended to occur earlier, and occurred signficantly more frequently at distant sites than in thymoma (60% vs. 13%, p=0.01). Conclusions Patterns of relapse differ significantly between TC and thymoma with lower progression-free survival, earlier onset and more distant relapses in TC. Given the greater propensity for distant failures, the inclusion of systemic therapy in the treatment of TC may take on greater importance. Despite significantly higher rates of distant relapse, good overall survival in TC can be achieved.

Patterns of metastasis and recurrence in thymic epithelial tumours: longitudinal imaging review in correlation with histological subtypes

“…Metastasis or recurrence occurred more frequently in high-risk thymomas (B2 and B3) than low-risk thymomas (A, AB, and B1). The results support the previously reported observations indicating more aggressive behaviours of thymic carcinomas compared to thymomas, as well as the association between oncological behaviour and the WHO histological classifications of thymic tumours 7, 21, 32 .…”

“…This finding is similar to the recent report of Ruffini et al , 31 which noted 24 cases of locoregional (including 12 pleural) recurrence among 47 thymic carcinoma patients, although the frequency of pleural involvement was higher in the present cohort. Lung metastasis was significantly more common in thymic carcinomas than in thymomas, as were the other sites of haematogenous spread, which supports the observations by Huang et al 21 in their prior study comparing thymomas and thymic carcinomas. Thoracic nodal involvement was noted in supraclavicular, para-oesophageal, retrocrural, pericardial, and axillary nodes; however, no other mediastinal or hilar nodes were involved, which contrasts the patterns of spread in other types of thoracic malignancy such as lung cancer.…”

“…Frequent pleural involvement was expected and was as described in previous reports 21, 33 ; however, no difference was noted for the frequency of pleural involvement between thymomas and thymic carcinomas. Indeed, 60% (6/10) of thymic carcinoma patients with metastasis had pleural involvement, indicating it is a common pattern of spread in this group as well.…”

“…Among the few prior reports for prognostic factors of thymoma after surgical resection and relapse patterns focusing on clinical outcome, Huang et al 21 studied 120 patients with thymic epithelial tumours who underwent surgical intervention, and reported that thymic carcinoma patients had significantly shorter 5-year overall and progression-free survival than thymoma patients, and had earlier occurrence of relapse, which was more frequent at the distant sites. Given the important role of imaging in the follow-up evaluations of patients with thymic epithelial tumours, a systematic radiological investigation based on the longitudinal imaging data may help to provide additional important knowledge of these tumours and may contribute to improve patient management.…”

Treatment Modalities and Outcomes in Patients With Advanced Invasive Thymoma or Thymic Carcinoma

“…Consistent with our results, Huang et al found differing patterns of relapse between patients with thymic carcinoma versus thymoma, with thymic carcinoma being associated with lower progression-free survival and higher rates of distant failures. 19 If complete or incomplete resection can be achieved, long-term survival rates have been as high as 60%–70% for those who receive adjuvant treatment. 6–8 A multimodality approach such as trimodality therapy or definitive concurrent chemoradiation in unresectable cases is recommended for thymic carcinoma regardless of disease stage.…”