The metastatic risk profile of microscopic lymphatic and venous invasion in medullary thyroid cancer is ill-defined. This evidence gap calls for evaluation of the suitability of microscopic lymphatic and venous invasion at thyroidectomy for prediction of lymph node and distant metastases in medullary thyroid cancer. In this study of 484 patients with medullary thyroid cancer who had≥5 lymph nodes removed at initial thyroidectomy, microscopic lymphatic and venous invasion were significantly associated with greater primary tumor size (27.6 vs. 14.5 mm, and 30.8 vs. 16.2 mm) and more frequent lymph node metastasis (97.0 vs. 25.9%, and 85.2 vs. 39.5%) and distant metastasis (25.0 vs. 5.1%, and 32.8 vs. 7.3%). Prediction of lymph node metastases by microscopic lymphatic invasion was better than prediction of distant metastases by microscopic venous invasion regarding sensitivity (97.0 vs. 32.8%) and positive predictive value (58.4 vs. 39.2%); comparable regarding negative predictive value (98.5 vs. 90.5%) and accuracy (80.4 vs. 85.1%); and worse regarding specificity (74.1 vs. 92.7%). On multivariable logistic regression, microscopic lymphatic invasion predicted lymph node metastasis better (odds ratio [OR] 65.6) than primary tumor size (OR 4.6 for tumors>40 mm and OR 2.7 for tumors 21–40 mm, relative to tumors≤20 mm), whereas primary tumor size was better in predicting distant metastasis (OR 8.3 for tumors>40 mm and OR 3.9 for tumors 21–40 mm, relative to tumors≤20 mm) than microscopic venous invasion (OR 3.2). These data show that lymphatic invasion predicts lymph node metastases better in medullary thyroid cancer than venous invasion heralds distant metastases.

中文翻译：

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甲状腺髓样癌显微镜下淋巴和静脉浸润的转移风险概况

甲状腺髓样癌显微镜下淋巴和静脉浸润的转移风险特征不明确。这一证据差距要求评估甲状腺切除术中显微镜下淋巴和静脉浸润对预测甲状腺髓样癌淋巴结和远处转移的适用性。在这项研究中，484 名甲状腺髓样癌患者在初次甲状腺切除术时切除了≥5 个淋巴结，显微镜下淋巴和静脉侵犯与更大的原发肿瘤大小（27.6 对 14.5 毫米，30.8 对 16.2 毫米）及更多显着相关频繁淋巴结转移（97.0 对 25.9%，85.2 对 39.5%）和远处转移（25.0 对 5.1%，32.8 对 7.3%）。在敏感性（97.0 vs. 32.8%）和阳性预测值（58.4 vs. 39.2%）方面，通过显微镜下淋巴浸润预测淋巴结转移优于通过显微镜下静脉浸润预测远处转移；在阴性预测值（98.5 对 90.5%）和准确度（80.4 对 85.1%）方面具有可比性；特异性更差（74.1 对 92.7%）。在多变量逻辑回归中，显微镜下淋巴浸润预测淋巴结转移（优势比 [OR] 65.6）优于原发肿瘤大小（肿瘤>40 mm 的 OR 4.6 和 21-40 mm 的肿瘤 OR 2.7，相对于肿瘤≤20 mm） ，而原发性肿瘤大小在预测远处转移方面更好（肿瘤> 40 mm的OR 8.3和肿瘤21-40 mm的OR 3.9，相对于肿瘤≤20 mm）比显微镜下静脉浸润（OR 3.2）更好。