Bhatia S, Pratt C B, Sharp G B, Robison L L
Division of Pediatrics, City of Hope National Medical Center, Duarte, California, USA.
Med Pediatr Oncol. 1999 Nov;33(5):470-5. doi: 10.1002/(sici)1096-911x(199911)33:5<470::aid-mpo6>3.0.co;2-a.
Family history of colorectal cancer among adult patients has been reported in the literature. Although extremely rare in children, colorectal cancer in this population may represent a unique group in whom genetic factors play a significant etiologic role. The aim of the present study was to assess genetic contribution, as measured by family history, to the development of colorectal cancer in probands under 21 years of age at diagnosis.
Detailed family histories were obtained from surviving patients or their parents. The risk [standardized incidence ratio (SIR)] of cancer in the relatives was calculated by comparing the observed and the expected incidence based on rates in the general population and person-years at risk.
Twenty-five patients (median age at diagnosis 15 years) diagnosed with colorectal cancer at St. Jude Children's Research Center since 1964 or their surviving next of kin were available for interview. The 461 relatives contributed 18,908 person-years of follow-up. Statistically significant increased risk of colorectal cancer was present among all relatives (SIR = 6.0, 95% CI, 2.7-10.6), and the increased risk of colorectal cancer was confined to relatives of probands who were under 15 years of age at diagnosis (SIR = 10.0, 95% CI, 4.5-17.6). In addition, there was an excess of uterine/cervical cancer among all female relatives (SIR = 6.5, 95% CI, 3.2-10.9).
The observed excess of colorectal cancer, in relatives of younger probands, suggests the need to examine these kindreds for genetic instability resulting from defects in mismatch repair genes to characterize further the patterns of risk observed.
文献中已报道成年患者的结直肠癌家族史。尽管儿童结直肠癌极为罕见，但该人群中的结直肠癌可能代表了一个独特的群体，其中遗传因素起着重要的病因学作用。本研究的目的是评估家族史所衡量的遗传因素对诊断时年龄在21岁以下的先证者患结直肠癌的影响。
从存活患者或其父母处获取详细的家族史。通过比较观察到的发病率与基于一般人群发病率和风险人年数预期的发病率，计算亲属患癌风险[标准化发病比（SIR）]。
自1964年以来在圣裘德儿童研究中心诊断为结直肠癌的25名患者（诊断时中位年龄15岁）或其存活的近亲可供访谈。461名亲属提供了18908人年的随访数据。所有亲属患结直肠癌的风险在统计学上显著增加（SIR = 6.0，95%可信区间，2.7 - 10.6），结直肠癌风险增加仅限于诊断时年龄在15岁以下的先证者的亲属（SIR = 10.0，95%可信区间，4.5 - 17.6）。此外，所有女性亲属中子宫/宫颈癌的发病率也有所增加（SIR = 6.5，95%可信区间，3.2 - 10.9）。
在较年轻先证者的亲属中观察到的结直肠癌发病率过高，表明有必要检查这些家族中错配修复基因缺陷导致的遗传不稳定性，以进一步明确所观察到的风险模式。
