Management of Thymic Neoplasms: Egyptian NCI Experience

Abstract

Background: Thymic tumors are rare entity with little information regarding outcomes after therapy with curative intent. They are heterogeneous group of neoplastic lesions with wide spectrum of morphologic appearances. They show different presentations with a variable & unpredictable evolution ranging from indolent attitude to highly infiltrative and metastasizing one. The optimal treatment includes surgical resection, chemotherapy, and radiotherapy. Objectives: To analyze, to report & to better understand the clinico-pathologic features, results of treatment, and prognostic factors of these tumors. Materials and Methods: From 2008 to 2014, 13 patients (8 men, 5 women) underwent surgical resection of thymic tumor at a mean age of 47 years. Patient demographics, extent of surgical resection, and outcomes were compiled. Demographic variables, use of chemotherapy or radiotherapy, peri-operative variables, recurrence rates, and long term survival were analyzed retrospectively. The Masaoka stage and tumor diameter were recorded along with other variables that potentially influenced survival such tumor grade, site & number of metastatic disease. Results: The mean age of our patients was 47 years (range: 21 to 58 years) & 8 cases (61.5%) were men. The distribution of patients according to the Masaoka staging at presentation was, stage I (6 cases, 47%), stage II (3 cases, 23%), stage III in (1 patient, 7%), and stage IV (3 cases, 23%). Neoadjuvant chemotherapy was administered to 3 patients (23%) whose tumors were deemed to be more locally advanced precluding R0 resection from the start & 2 patients (15%) received neoadjuvant concomitant chemo-radiotherapy. No patient demonstrated an associated immunologic disorder such as myasthenia gravis. In all patients (13 cases, 100%) pathologic confirmation of thymic tumor was by CT guided fine needle aspiration/biopsy. Surgical resection was done for all our cases (13 patients, 100%) through median sternotomy approach in (11 cases, 86%), cervical approach (1 patient, 7%) & transverse sternotomy with clamshell incision in 1 patient (7%) with a large thymic carcinoma whose postoperative pathology revealed a close margin of resection (R1). Resection of nearby structures was done in our cohort to fulfill R0 resection; pulmonary wedge resection in (2 cases, 15%), pleural resection in (5 cases, 38%), lobectomy in (1 patient, 7%) & unilateral phrenic nerve resection was performed in (2 patients, 15%). None patients with phrenic nerve injury underwent diaphragmatic plication to improve respiratory insufficiency No superior vena cava resection was done in any of our cases. There were no perioperative deaths, tracheostomy, or postoperative respiratory failure occurred. Complete R0 resection was achieved in 12 cases (92.3%), and of these patients, only 1 patient (7.7%) experienced local recurrence whose primary resection was R1. 4 patients received adjuvant chemotherapy or radiotherapy or both. Mean duration of survival in the entire group was 22.7 months (range: 14 to 36 months). At the last follow-up, (8 patients, 61.5%) were alive without disease, (1 case, 7.5%) was alive with disease, and (4 cases, 31%) were dead. Conclusions: Thymic tumors are amenable to surgical therapy, with increased use of computed tomography imaging. Patients with early stage disease are being identified more frequently. Complete surgical resection appears to have favorable cure rates in these patients. Patients with locally advanced disease can experience long term survival with a multimodality approach.