Background: Excess adipose tissue has been associated with the increased prevalence and aggressiveness of many human cancers. While its role in differentiated thyroid cancer is well established, in medullary thyroid cancer (MTC), data are conflicting. We aimed to evaluate the impact of excess adipose tissue on MTC prevalence, aggressiveness at diagnosis, and outcome in a large series of patients.Methods: We evaluated 529 patients with sporadic MTC from a prospectively maintained database. Weight and height were measured in all patients at the time of surgery, and body mass index (BMI) was calculated. Therefore, patients were classified according to BMI categories suggested by the WHO for Caucasian patients. Data about somatic mutations were available in 254/529 patients (48.0%).Results: The prevalence of subjects with obesity was higher than that in the Italian general population (20.2 vs. 12.0%). Patients with obesity presented smaller tumors, lower T and N stage, and lowerAJCC 8th editionstage, as well as lower preoperative calcitonin values compared to under/normal and overweight ones. The prevalence of somaticRETandRASmutations did not differ significantly across the WHO BMI categories. At the end of follow-up, structural disease was less common in patients with obesity (15.4%) compared to under/normal (25.6%,p< 0.05) and overweight (24.1%,p= 0.079). Further surgeries for local recurrence were less common in patients with obesity (3.8%) compared to overweight ones (11.0%,p< 0.05). Survival was superimposable in the different categories of BMI.Conclusions: Among patients with sporadic MTC, there is a higher prevalence of patients with obesity compared to the general population. A higher BMI was associated with less aggressive clinical presentation and better clinical outcomes.
背景：过量脂肪组织与多种人类癌症发病率升高及侵袭性增强相关。其在分化型甲状腺癌中的作用已明确，但在甲状腺髓样癌（MTC）中相关研究结论存在矛盾。本研究旨在通过大样本患者队列评估过量脂肪组织对MTC发病率、诊断时侵袭性及预后的影响。 方法：我们从前瞻性维护数据库中纳入529例散发性MTC患者。所有患者均在手术时测量体重与身高并计算体重指数（BMI）。根据世界卫生组织针对白种人群的BMI分类标准对患者进行分级。其中254例（48.0%）患者可获得体细胞突变数据。 结果：肥胖患者比例显著高于意大利普通人群（20.2% vs. 12.0%）。与体重不足/正常及超重患者相比，肥胖患者肿瘤体积更小，T分期与N分期更低，AJCC第8版分期更低，术前降钙素水平也更低。不同WHO BMI分级组间RET与RAS体细胞突变发生率无显著差异。随访结束时，肥胖患者结构性病灶发生率（15.4%）低于体重不足/正常组（25.6%，p<0.05）和超重组（24.1%，p=0.079）。肥胖患者因局部复发再次手术的比例（3.8%）显著低于超重组（11.0%，p<0.05）。不同BMI分级组间生存率无显著差异。 结论：在散发性MTC患者中，肥胖患病率高于普通人群。较高的BMI与侵袭性更低的临床表现和更好的临床预后相关。
Body Mass Index and Sporadic Medullary Thyroid Cancer: Insights from a Large Series
肿瘤(癌症)患者之家