Persistent and Aggressive Treatment for Thymic Carcinoma

Objectives: The aim of this study is to retrospectively evaluate the role of several therapies, mainly chemotherapy, for thymic carcinoma (TC). Methods: From July 1973 to July 2005, 25 patients (15 males and 10 females) with histologically proven TC were treated at our department. The median age of the patients was 59 years, with a range of from 30 to 78 years. According to Masaoka’s staging system, there was 1 stage I patient, 3 stage II, 7 stage III, 6 stage IVa, and 8 stage IVb patients. The histological subtype was in all cases squamous cell carcinoma, nonkeratinizing type. Results: There were 6 complete surgical resections, 1 incomplete resection followed by chemoradiotherapy, 6 with radiotherapy alone, 3 with radiotherapy plus chemotherapy, and 9 with chemotherapy alone as the initial treatment. Eighteen patients were administered second-line therapy. The regimen obtaining the best response rate was doublet chemotherapy consisting of carboplatin (CBDCA) and paclitaxel. The median survival time and survival rate at 5 years for the patients excluding surgical cases with stage I/II disease were 32 Received: February 17, 2006 Accepted after revision: July 3, 2006 Published online: December 12, 2006 Oncology Dr. Yukito Ichinose Department of Thoracic Oncology, Kyushu Cancer Center 3-1-1, Notame Minami-ku, Fukuoka 811-1395 (Japan) Tel. +81 92 541 3231, Fax +81 92 551 4585, E-Mail [email protected] © 2006 S. Karger AG, Basel 0030–2414/06/0705–0325$23.50/0 Accessible online at: www.karger.com/ocl Maruyama et al. Oncology 2006;70:325–329 326 carcinoma, sarcomatoid carcinoma (carcinosarcoma), clear cell carcinoma, adenocarcinoma, papillary adenocarcinoma, carcinoma with t(15; 19) translocation, and undifferentiated carcinoma [2] . Whereas the clinicopathological features of TC have often been discussed, information about the optimal treatment modalities and long-term prognosis is limited due to the rarity of this disease. We retrospectively reviewed 25 cases of TC treated with various modalities and followed them long-term, while also discussing the overall management of this disease. Material and Methods Patients and Methods From July 1973 to July 2005, 25 patients with histologically proven TC were treated at the Department of Thoracic Oncology, Kyushu Cancer Center. We excluded any thymic neuroendocrine tumors in this retrospective study, because their clinical behavior differs from that of the others. The clinical or pathological stage of the disease was based on the staging system described by Masaoka et al. [3] . The histological analysis of the tumor was based on the WHO classification of cell types [2] . Percutaneous biopsy was performed in the cases without a surgical resection to determine the pathological classification. The cases diagnosed before the establishment of the Masaoka criteria or WHO classification were reevaluated by two independent reviewers or pathologists. The clinicopathological characteristics of the patients are shown in table 1 . All patients had a good performance status except for performance status 2 due to the superior vena cava syndrome in only 1 patient. Treatment The initial therapies are summarized in table 2 . A complete resection as the initial therapy was performed in 6 patients, which included 1 patient who received postoperative radiotherapy and 1 postoperative chemotherapy. One patient had an incomplete resection followed by chemoradiotherapy, radiotherapy alone in 6, radiotherapy plus chemotherapy in 3, and chemotherapy alone in 9 as the initial treatment. Nine of the patients with unresectable tumors were treated with irradiation of from 40.0 to 61.2 Gy to the primary tumors. Eighteen patients were administered secondline therapy (chemotherapy in 10, radiotherapy in 4, chemoradiotherapy in 3 and surgical resection followed by radiotherapy in 1), while 12 received third-line (radiotherapy in 6, chemotherapy in 3, chemoradiotherapy, surgical resection and other treatment in 1 each), 10 had fourth-line (radiotherapy in 5, chemotherapy in 2, chemoradiotherapy in 2 and surgical resection followed by chemotherapy in 1), 4 had fifth-line (chemotherapy and radiotherapy in 2 each), 3 had sixth-line (surgical resection, radiotherapy and chemotherapy in 1 each) and 2 had seventh-line treatment (radiotherapy in 2) after the failure of the initial treatment. Several chemotherapy regimens were used, and the results of the firstor second-line chemotherapy for at least 4 patients are summarized in table 3 . Tumor Assessment during and after Treatment The measurability of target lesions at baseline and the response criteria was based on the Response Evaluation Criteria in Solid Tumours (RECIST) [4] . In brief, lesions that can be accurately measured in at least one dimension as 6 20 mm with conventional techniques or as 6 10 mm with a spiral CT scan were defined as measurable lesions. The response criteria were categorized as follows: complete response: the disappearance of all target lesions; partial response: at least a 30% decrease in the sum of the pleural thickness at three separate levels; progressive disease: at least a 20% increase in the sum of the pleural thickness at three separate levels or the appearance of one or more new lesions; stable disease: neither sufficient shrinkage to qualify for partial response nor a sufficient increase to qualify for progressive disease. The cases diagnosed before establishment of the RECIST criteria were reevaluated by two independent reviewers of our department. Statistical Analysis The duration of stable disease was measured from the start of the treatment until the criteria for disease progression was met. The survival was calculated from the date of the initial treatment until death due to any cause or the last follow-up (censored). The survival curve was made using the Kaplan-Meier method [5] . The Table 1. Clinicopathological characteristics of the patients