Department of Thoracic Surgery, University of Torino, Turin, Italy.
Eur J Cardiothorac Surg. 2013 Aug;44(2):219-24; discussion 224. doi: 10.1093/ejcts/ezs663. Epub 2013 Jan 11.
Although thymoma is considered a relatively indolent neoplasia, patients affected by this disease are at high risk of developing second tumours (STs). The aim of this study is to assess the risk of developing STs after surgical thymoma resection.
A multicentre retrospective study of patients operated on for thymoma within five Italian Thoracic Surgery Institutions, between 2000 and 2011, was conducted. The overall STs number and incidence were calculated. The number of metachronous STs was compared with the expected cancer number (ECN) in an Italian population, and the standardized incidence ratio (SIR) and 95% confidence intervals were calculated. Potential variables of STs predictors were also evaluated.
There were 302 patients; myasthenia gravis (MG) was observed in 166 (55%) and other autoimmune syndromes in 49 of them. In 118 patients (39.1%), the Masaoka thymoma stage was greater than II and in 194, the WHO histological type ranged from B1 to C. Fifty STs were observed (28 metachronous, 4 synchronous and 18 detected before thymoma). The observed metachronous STs number was significantly higher than ECN. An increased risk of STs development was observed in advanced stage thymomas and in those with histological high grade. On the contrary, MG seems to be a protective factor in STs development.
Our study confirms the high risk of developing STs in patients with thymoma. Aggressive forms of thymoma are those in which this risk appears to be more evident. The central role of an intrinsic immune system alteration might be the key to interpret this phenomenon.
尽管胸腺瘤被认为是一种相对惰性的肿瘤，但患有这种疾病的患者发生第二肿瘤（STs）的风险很高。本研究旨在评估胸腺瘤切除术后发生 STs 的风险。
对 2000 年至 2011 年间在意大利五家胸外科机构接受胸腺瘤手术的患者进行了一项多中心回顾性研究。计算了总 STs 数量和发病率。将同时性 STs 的数量与意大利人群的预期癌症数量（ECN）进行比较，并计算标准化发病比（SIR）及其 95%置信区间。还评估了 STs 预测因子的潜在变量。
共纳入 302 例患者；166 例（55%）患者存在重症肌无力（MG），49 例患者存在其他自身免疫性疾病。118 例（39.1%）患者的 Masaoka 胸腺瘤分期大于 II 期，194 例患者的 WHO 组织学类型为 B1 至 C 型。共观察到 50 例 STs（28 例为同时性，4 例为同步性，18 例在胸腺瘤之前发现）。观察到的同时性 STs 数量明显高于 ECN。高级别胸腺瘤和组织学高级别患者发生 STs 的风险增加。相反，MG 似乎是 STs 发展的保护因素。
本研究证实胸腺瘤患者发生 STs 的风险较高。侵袭性胸腺瘤的这种风险似乎更为明显。固有免疫系统改变的核心作用可能是解释这一现象的关键。
