Ito Yasuhiro, Miyauchi Akira, Yabuta Tomonori, Fukushima Mitsuhiro, Inoue Hiroyuki, Tomoda Chisato, Uruno Takashi, Kihara Minoru, Higashiyama Takuya, Takamura Yuuki, Miya Akihiro, Kobayashi Kaoru, Matsuzuka Fumio
Department of Surgery, Kuma Hospital, 8-2-35, Shimoyamate-dori, Chuo-ku, Kobe, 650-0011, Japan.
World J Surg. 2009 Jan;33(1):58-66. doi: 10.1007/s00268-008-9795-2.
Medullary thyroid carcinoma (MTC) accounts only for 1.4% of all thyroid malignancies in Japan. Since 1996, we have performed hemithyroidectomy, instead of total thyroidectomy, for sporadic nonhereditary MTC when the primary lesion is located in only one lobe. Regarding lymph node dissection, modified radical neck dissection (MND) at least ipsilateral to the tumor has been routinely performed, even if there is no clinically apparent metastasis. We investigated the clinical outcomes of MTC patients in our department.
A series of 118 patients with MTC who underwent initial surgery between 1975 and 2005 were enrolled in this study. The RET gene mutations were analyzed for all patients and 46 had germline RET gene mutations. Of those 46 patients, 26 were diagnosed as MEN 2A and 2 were diagnosed as MEN 2B. Postoperative follow-up periods averaged 141 months.
Of 115 patients who did not have distant metastasis at surgery and who underwent locally curative surgery, 78 (67.8%) were biochemically cured. All patients without pathological lymph node metastasis were biochemically cured, and 44.8% of patients with node metastasis were also biochemically cured. The 10-year and 20-year disease-free survival rates were 89.0% and 82.5%, respectively. None of the patients who did not show lymph node metastasis and only 2 (2.6%) of 78 patients who were biochemically cured showed clinically apparent carcinoma recurrence. The 10-year and 20-year cause-specific survival rates were 96.6% and 91.7%, respectively. Lymph node metastasis, tumor size>4 cm, extrathyroid and extranodal tumor extensions significantly affected cause-specific survival of patients.
Clinical outcomes of MTC patients in our series were better than those in Western countries, a result that might have resulted in part because of our routine MND regardless of whether clinically apparent node metastasis was detected.
在日本，甲状腺髓样癌（MTC）仅占所有甲状腺恶性肿瘤的1.4%。自1996年以来，对于散发性非遗传性MTC，若原发灶仅位于一侧叶，我们实施的是甲状腺半切术而非全甲状腺切除术。关于淋巴结清扫，即使无临床明显转移，也常规对肿瘤至少同侧实施改良根治性颈清扫术（MND）。我们对本部门MTC患者的临床结局进行了调查。
本研究纳入了1975年至2005年间接受初次手术的118例MTC患者。对所有患者进行RET基因突变分析，其中46例有生殖系RET基因突变。在这46例患者中，26例被诊断为MEN 2A，2例被诊断为MEN 2B。术后随访期平均为141个月。
115例手术时无远处转移且接受局部根治性手术的患者中，78例（67.8%）获得生化治愈。所有无病理淋巴结转移的患者均获得生化治愈，有淋巴结转移的患者中44.8%也获得生化治愈。10年和20年无病生存率分别为89.0%和82.5%。无淋巴结转移的患者均未出现临床明显的癌复发，在78例生化治愈的患者中仅2例（2.6%）出现临床明显癌复发。10年和20年病因特异性生存率分别为96.6%和91.7%。淋巴结转移、肿瘤大小>4 cm、甲状腺外和淋巴结外肿瘤侵犯显著影响患者的病因特异性生存。
我们系列研究中MTC患者的临床结局优于西方国家，这一结果可能部分归因于我们无论是否检测到临床明显的淋巴结转移均常规进行MND。
