遗传因素在乳头状甲状腺癌发生中的作用

Study of Genetic Effect on Papillary Thyroid Carcinoma

目的 探讨遗传因素在乳头状甲状腺癌 (PTC)发生中的作用。方法 采用以医院为基础的病例对照家系研究设计 ,采用Greenwood -Yule法和Haldane -Smith法 ,对 172例PTC先证者及 18例患PTC的亲属进行出生顺序分析。比较先证者一、二级亲属和一般人群的患病率 ,并进行零截尾负二项分布拟合检验 ,分析PTC是否具有家族聚集性。结果 Greenwood -Yule法的分析结果显示 ,PTC出生顺序的实际分布与期望分布相近 ,各出生顺序的实际数与期望数的比值在 1范围波动 ,表明PTC与出生顺序无关。Haldane -Smith法计算得C = 6A实际值 - 6A理论值 / V6A =0 5 67,P >0 0 5 ,实际值与期望值的差异无统计学意义 ,亦表明PTC与出生顺序无关。PTC患者的一、二级亲属和人群患病率分别为 1 0 8%、0 42 %和 0 0 9% ,其中 ,一、二级亲属患病率的差异有统计学意义 (χ2 =4 0 7,P =0 0 44 ) ,二级亲属与人群患病率的差异亦有统计学意义 (FisherP =0 0 46) ,PTC患病率存在一级亲属 >二级亲属 >一般人群的规律。零截尾负二项分布拟合检验结果表明 ,PTC在家系中的分布符合零截尾负二项分布 (χ2 =0 13 ,P >0 0 5 ) ,PTC的发生存在家族聚集性。结论 遗传因素可能是PTC的主要危险因素 ,PTC可能是一种多因子遗传病。

Objective To assess the effect of the genetic factors on the papillary thyroid carcinoma(PTC). Methods A hospital-based case-control study was carried out.A birth order study was conducted among 172 probands and 18 affected relatives.The prevalence rates of the first-degree relatives,the second-degree relatives and the population were calculated.The falmily aggregation was assessed through zero-truncated negative binomial distribution model. Results The result from the method of Greenwood-Yule showed that there was no relation between PTC and the birth order.The analysis with the method of Haldane-Smith suggested the same result:6A actual value=2 664,6A expected value=2 718,V6A=9 084,C=6A actual value-6A expected value/V6A=0.567(P>0.05).The prevalence rates of the first-degree relatives,the second-degree relatives and the population were 1.08%,0.42% and 0.09%,respectively.There was statistically significant difference between the first-degree and second-degree relatives (χ2=4.07,P=0.044).The difference existed between the second-degree relatives and the population as well(Fisher P=0.046).The distribution of PTC accorded with zero-truncated negative binomial distribution in the affected families(χ2=0.13,P>0.05),which indicated that PTC had the family aggregation. Conclusions The genetic factors may be the major risk factors of PTC.The PTC might be a kind of multifactorial genetic disease.