胸腺上皮肿瘤的临床CT表现与术后存活时间的关系

Correlation between the CT manifestations and post-operative survival time in patients with thymicepithelial tumor

目的分析胸腺上皮肿瘤的临床和CT表现与患者术后存活时间的相关性。方法回顾性复习91例经手术病理证实，并作了WHO病理分类的胸腺上皮肿瘤的CT表现。根据肿瘤大小、形态、边缘、密度、强化程度、纵隔淋巴结、有无大血管侵犯及肺内或胸膜转移灶，并结合是否伴发重症肌无力、WHO病理分类等，评价各因素对患者预后的影响。用Kaplan-Meier法计算总生存率，Logrank检验用于评价各因素间的差异，Cox回归比例风险模型用于多因素分析影响存活的预后因素，X^2检验用于分析CT表现与WHO分类的关系。结果91例中因非肿瘤因素病死2例，其余89例中病死13例，5年总生存率为84．3％（75例）。89例共有病灶91个，在CT表现上肿瘤≥5cm、边缘分叶、密度不均匀、出现血管侵犯、纵隔淋巴结肿大及有远处转移者存活时间较短，5年生存率分别为72．7％、77．3％、76．7％、73．8％、30．0％、68．8％。多因素分析显示肿瘤大小、患者是否合并重症肌无力和是否出现纵隔肿大淋巴结是影响预后的独立影响因素，其偏回归系数（B）分别为0．378、-1．756和1．853，P值分别为0．002，0．009和0．025。CT表现与WHO分类的比较结果和单因素分析结果一致，WHO病理分类不同，则肿瘤的大小、边缘、血管侵犯情况、纵隔淋巴结肿大以及是否有远处转移差异有统计学意义（x。值分别为6．598、5．737、18．307、8．465、15．608，P值均〈0．05）。结论CT表现可以提示肿瘤的生物学特性，肿瘤大小和有无纵隔淋巴结肿大是影响患者存活时间的主要因素，而伴发重症肌无力多提示肿瘤级别较低，患者存活时间相对较长。

explore the correlation between CT findings and post-operative tumor-related survival time. Methods Ninety-one patients who underwent CT scan before operation were reviewed retrospectively. All cases had operation and were classified according to the WHO classification. The size, contour, shape, density and enhancement of the tumors on CT were assessed. Presence of mediastinal lymphadenopathy, great vessel invasion, metastasis to the lung or plural, myasthenia gravis （MG） were also analyzed. The survival rate was obtained using the Kaplan-Meier method. The Cox model was applied to determine the factors affecting the tumor-related survivals. Chi square test was used to analyze the relationship between CT findings and WHO classification. Results Two patients were excluded because of dying of myocardial infarction and colon cancer. The total 5-year survival rate was 84. 3% （ n = 75）. Eighty-nine patients had total 91 tumors. Tumors with diameter larger than 5 cm, lobular contour, heterogenous density, and presence of great vessel invasion, mediastinal lymphadenopathy, and metastasis were adverse factors which could significantly affect the survival time. Five-year survival rates of these factors were 72. 7% , 77. 3% , 76. 7% , 73.8% , 30. 0% , and 68.8% , respectively. Presence of MG was a favorable factor which also significantly affected the survival time （ P 〈 0. 05 ）. While the shape and enhancement of the tumors and the age, gender of the patients did not significantly affect the survival time （ P 〉 0. 05 ）. The result of the Cox multivariate analysis was consistent with that of the Log-rank test. For different WHO classification, there were significant different among the size or contour of the tumors, presence of great vessel invasion, mediastinal lymphadenopathy, and metastasis （ X^2 value were 6. 598, 5. 737, 18. 307, 8. 465, and 15. 608, respectively P 〈 0.05） . Condusions CT findings may be served as predictors of clinical prognosis of the thymic epithelial tumors.Adverse factors for survival time are the size of the tumors and presence of mediastinal lymphadenopathy, while MG is a favorable factor for survival time.