BACKGROUND

Thymic carcinomas (TCs) are rare aggressive tumors with no standard first-line treatment. This study was conducted to determine the optimal chemotherapy regimen for advanced TC.

METHODS

This retrospective study included 67 patients treated for stage IV TC in 2006-2015. The primary endpoints were the objective response rate (ORR) and progression-free survival (PFS) with different chemotherapy regimens. Multivariate Cox regression analysis was used to identify factors associated with PFS, including metastatic status, radiotherapy post-chemotherapy, primary lesion resection before chemotherapy, and chemotherapy regimen.

RESULTS

A total of 36 patients received a paclitaxel-platinum regimen, 31 received a gemcitabine-platinum regimen, 14 underwent primary lesion resection, and 33 underwent radiotherapy. ORR was 31% (11/36) and 29% (9/31) in the paclitaxel-platinum and gemcitabine-platinum groups, respectively (P = 0.890). Median PFS, one-year PFS rate, and two-year PFS rate were 7.0 months, 26%, and 6% with paclitaxel-platinum treatment and 12 months, 48%, and 24% with gemcitabine-platinum treatment (log-rank P = 0.030). Median PFS, one-year PFS rate, and two-year PFS rate were 18.0 months, 57%, and 33% with surgical resection and 7.3 months, 31%, and 7% without resection (log-rank P = 0.030). Median PFS, one-year PFS rate, and two-year PFS rate were 13.0 months, 52%, and 20% with radiotherapy and 4.3 months, 22%, and 7% without radiotherapy (log-rank P = 0.001). In multivariate analysis, metastatic status (hazard ratio [HR], 0.33, P = 0.004), surgical resection (HR, 0.32; P = 0.004), and radiotherapy (HR, 0.32; P < 0.001) were associated with superior PFS.

CONCLUSIONS

Both gemcitabine-platinum and paclitaxel-platinum regimens were efficacious for advanced TC. Primary lesion resection and radiotherapy may also benefit selected patients.