NKX2-1 and Superior Vena Cava Syndrome: Between the chemotherapy-insensitive group (n = 32) and the chemotherapy-sensitive group (n = 110), no significant differences were observed in sex, age, smoking status, tumor size, lymph-node metastasis, vascular invasion, carcinomatous lymphangitis, mediastinal invasion, superior vena cava syndrome, tumor stage, brain metastases, pleural metastasis, lung metastasis, adrenal metastasis, or the immunohistochemical markers cytokeratin, synaptophysin, chromogranin A, thyroid transcription factor-1, and Ki-67 (all P > .05).