原发性肝癌与出生顺序的研究

目的：分析原发性肝癌患者的出生顺序，探讨环境因素与肝癌的关系。方法：根据Greenwood及Haldane的出生顺序方法，对来自江苏省海门市8年随访队列的100个家系中100例先证者及22例患病同胞进行出生顺序研究，结果：Greenwood法分析结果显示，患者出生顺序在1－3胎次的个体较多，当控制了乙型肝炎病毒感染的影响后，结果仍显示肝癌病人好生出生顺序较早的个体。Haldane法计算∑6A实验值＝1806，∑A理论值＝1988，实际6A值与期望6A值相差两个标准差以上，|∑6A实际值－∑6A期望值|／√∑V6A=2.1657，差异有显著的统计学意义（0．02＜P＜0．05），实际6A值比期望6A值小，说明出生顺序越小的个体越容易患肝癌，生态学研究结果显示，海门市普及自来水10年后的肝癌死亡率随时间推移明显下降，经Spearman相关显著性检验，相关系数为－0．818（P＜0．01），提示早期出生的个体中肝癌的发病与当地饮用水的水质有关。结论：肝癌的发生与出生顺序有关，发生在出生较早的个体，这与国外报道的肝癌好发于出生顺序较晚个体的结论不一致。生态学研究表明，长期饮用沟塘水与肝癌好在出生顺序较早的个体有关，提示环境因素对肝癌的发生有一定的影响。

A study on the relationship of birth order hepatocellular carcinoma

OBJECTIVE: To explore the association of hepatocellular carcinoma (HCC) with environmental factors through analyzing birth order data from pedigree sibships. METHODS: A birth order study was conducted based on the methods of Greenwood and Haldane for 100 probands and 22 affected siblings from 100 pedigrees in a cohort which was followed up for 8 years in Haimen, Jiangsu, China. RESULTS: The findings from the Greenwood method suggested that there was a tendency for cases of HCC to concentrate at lower birth orders of 1 to 3. With the effects of hepatitis B virus on the birth orders being controlled, the same tendency was also observed. The results from Haldane method showed that difference between actual value and expected value of 6A was more than the double standard deviation. Sigma 6A(actual value) = 1,806, Sigma 6A(expected value) = 1,988, the absolute value of (Sigma 6A(actual value) - Sigma 6A(expected value))/the square root of Sigma V6A = 2.1657 (0.02 < P < 0.05). The actual value of 6A was lower than the expected value of 6A suggesting that individuals at lower birth orders were at a higher risk of suffering from HCC. In addition, through data from ecologic research, there was a decreasing tendency of mortality of HCC within 10 years after the prevalence of tap water in Haimen city. The correlation coefficient by Spearman test was -0.818 (P < 0.01). The contribution of the quality of drinking water in the locality to the onset of HCC was found among people born in earlier period. CONCLUSIONS: There was a tendency that the onset of HCC cases concentrating was at lower birth orders in this research, which was inconsistent with several reports of foreign authors' which showed a reverse tendency. According to the ecological results, it was suggested that long-term drinking of ditch-water was responsible for the tendency of cases of HCC concentrating at lower birth orders. There were also certain effects of environmental factors exerted on the onset of HCC being discovered.