Multimodal management of stages III-IVa malignant thymoma.

Purpose: The optimal therapy for locally advanced malignant thymoma is controversial. We review our experience with a multimodal approach in 63 consecutive cases.

Patients And Methods: Forty-three patients had stage III and 20 stage IVa disease. Surgery with radical intent was initially performed in 30 cases, while 33 cases not amenable to radical surgery underwent neoadjuvant treatment (radiotherapy in 8 and chemotherapy in 25) before surgical reassessment. All patients, whether or not surgically resected, received radiation therapy.

Results: Radical resection (RR) was performed in 20 patients ab initio (all stage III) and in 12 patients after neoadjuvant treatment (eight stage III and four stage IVa). With the addition of patients radically operated with neoadjuvant treatment, the radical resection rate increased from 46 to 65% in stage III patients, and from 0 to 20% in those with stage IVa disease, respectively. Radical surgery was associated with longer progression free survival and overall survival according to both univariate analysis ( P< 0.001 and P<0.01, respectively) and multivariate analysis after adjustment for age, gender, histology and disease stage ( P<0.001 and <0.02, respectively). Progression free survival (median 56.9 months) was slightly lower in patients undergoing radical surgery after neoadjuvant approaches than in those radically resected ab initio (median not achieved), but overall survival (median not achieved) was similar in both groups. Subtotal surgical resection promoted complete response to subsequent radiation therapy. This condition significantly correlated with a better outcome.

Conclusions: Complete surgical resection is an independent prognostic parameter in locally advanced thymoma treated with a multimodal approach. Preoperative treatment to increase the complete resection rate could improve the overall survival of these patients.