Correlation Between Body Mass Index And The Clinicopathological Characteristics Of Papillary Thyroid Carcinoma

Objective:In the past decades,the incidence of thyroid cancer?TC?in most regions of the world has increased annually.The most pathological type in clinicals is thyroid papillary carcinoma?PTC?.It's believed that the over-diagnosis of thyroid micropapillary carcinoma?PTMC?is the major of PTC growth,leading to an increase of TC.However,this view cannot fully explain the increase of TC,especially the increase in tumor volume>1 cm and III and IV stage.A number of studies have shown that obesity is a clear risk that induces an increase of PTC.However,the association between obesity and the clinical pathological characteristics of PTC is still not clear,and lack of big data and prospective studies.This study was to investigate the relationship between the pathological characteristics of PTC and the body mass index?BMI?of Chinese people.Methods:We retrospectively analyzed the clinical data of 1131 patients who underwent surgical treatment at the Tianjin Medical University Cancer institute&Hospital from May 2015 to July 2016 and whose pathological report results were PTC?including PTMC?,including the patient's age,gender,Blood lipids,thyroid stimulating hormone?TSH?,height,weight,tumor diameter,multifocality,ETE,lymph node metastasis,and TNM stage.Univariate analysis was performed using?² test,Fisher's exact test,and Bonferroni method.Logistic regression analysis was used for multivariate analysis to compare the clinical pathological features of PTC in patients with different BMI.Results:1.In the study,246 were males and 885 were females,of which 347?30.68%?had menopause.The age ranged from 18 to 72 years,with an average age of 45.22?±10.44?years,a median age of 46 years.529 cases were<45 years?46.77%?and 602?53.23%??45 years.593 patients were with hyperlipidemia?52.4%?.the BMI was16.37-48.33 kg/m²,the average was 25.69?±3.89?.732 cases?64.72%?extrathyroidal extension?ETE?,and 221 cases?19.54%?were multifocality.462 cases lymph node metastasis?40.85%?.734 cases?64.9%?were T2/3/4 stage.706 patients?62.42%?were stage I and II,and 425?37.58%?were stage III and IV.2.In the univariate analysis,there was a statistically significant difference in gender,age,lymph node metastasis,and TNM stage between overweight group and normal weight group?p<0.017?and gender,age,ETE,T stage and TNM stage between obese group and normal weight group?p<0.017?.3.Multivariate regression analysis showed that the proportion of males?OR=2.622,p<0.001?,advanced age?OR=2.705,p<0.001?and III/IV stages?OR=1.955,p<0.001?in overweight group were increasing compared with normal weight group.The proportion of males?OR=5.455,p<0.001?,senior age?OR=1.422,p=0.045?,risk of ETE?OR=1.951,p=0.005?and T2/3/4 stage?OR=2.280,p<0.001?in obese group were increasing compared with normal weight group.4.In females,the proportion of advanced age?OR=4.726,p<0.001?,III and IV stages?OR=1.865,p<0.001?in overweight group was increased significantly.The risk of III,IV stage?OR=1.869,p=0.028?and T_2/3/4?OR=2.292,p=0.005?in obese group were absolutely ascending compared to the normal weight group.Conclusions:1.Compared with normal weight group,the proportion of males,advanced age and III and IV stage in overweight group was higher?p<0.05?,suggesting that the risk of advanced TNM stage in PTC increased as the BMI ascending.Compared with normal weight group,the proportion of males,advanced age,ETE and T_2/3/4 in obese group was higher?p<0.05?suggested that obesity may promote extrathyroidal invasion and metastasis of PTC.2.The biological behavior of PTC is affected by many factors including gene,race,sex,and hormone.High BMI is associated with ETE and advanced stage.It is an important risk factor in inducing malignant biological behavior of tumors.