Department of General Surgery, Manchester Royal Infirmary, Central Manchester University Hospitals Foundation Trust, Manchester, UK.
Colorectal Dis. 2013 Mar;15(3):309-16. doi: 10.1111/codi.12005.
Lifetime risk of a metachronous colorectal cancer (mCRC) is 0.6-3% following sporadic colorectal cancer (CRC) and 15-26% in Lynch syndrome. The lifetime incidence of CRC in individuals with moderate familial risk is 8-17%. Risk of mCRC is unknown.
A retrospective longitudinal study of the Regional Familial CRC Registry was performed. Patients who had at least one CRC were categorized as follows: moderate risk (n = 383), Lynch syndrome (n = 528) and average (population) risk (n = 409). The Kaplan-Meier estimate (1-KM) and the cumulative incidence function were used to calculate the risk of mCRC. The 1-KM gives the risk for individuals remaining at risk (alive) at a given time point and thus is useful for counselling. The cumulative incidence function gives the risk for the whole population.
The 1-KM and the cumulative incidence function demonstrated that the risk of mCRC was significantly higher in moderate-risk patients compared with average (population)-risk patients (1-KM, P = 0.008; cumulative incidence function, P = 0.00097). However, the risk of mCRC was higher in patients with Lynch syndrome than in moderate-risk or average (population)-risk patients. The 1-KM in moderate-risk patients was 2.7%, 6.3% and 23.5% at 5, 10 and 20 years, respectively. In average (population)-risk patients, the 1-KM was 1.3%, 3.1% and 7.0% at 5, 10 and 20 years, and the cumulative incidence function was 0.3%, 0.6% and 2.4% at the same time points, respectively.
These data indicate that the risk of mCRC is significantly higher in patients with a moderate family history of CRC than in those with an average (population) risk. This justifies proactive lifelong surveillance.
散发性结直肠癌（CRC）患者发生异时性结直肠癌（mCRC）的终生风险为 0.6-3%，林奇综合征患者为 15-26%。家族中度结直肠癌风险患者的终生 CRC 发病率为 8-17%。mCRC 的风险未知。
对区域性家族性 CRC 登记处进行了回顾性纵向研究。至少患有一次 CRC 的患者被分为以下几类：中度风险（n=383）、林奇综合征（n=528）和平均（人群）风险（n=409）。使用 Kaplan-Meier 估计（1-KM）和累积发生率函数来计算 mCRC 的风险。1-KM 给出了在给定时间点仍处于风险中（存活）的个体的风险，因此对于咨询很有用。累积发生率函数给出了整个人群的风险。
1-KM 和累积发生率函数表明，中度风险患者的 mCRC 风险明显高于平均（人群）风险患者（1-KM，P=0.008；累积发生率函数，P=0.00097）。然而，林奇综合征患者的 mCRC 风险高于中度风险或平均（人群）风险患者。中度风险患者的 1-KM 在 5、10 和 20 年时分别为 2.7%、6.3%和 23.5%。在平均（人群）风险患者中，1-KM 在 5、10 和 20 年时分别为 1.3%、3.1%和 7.0%，累积发生率函数分别为 0.3%、0.6%和 2.4%。
这些数据表明，与平均（人群）风险患者相比，有中度结直肠癌家族史的患者 mCRC 的风险明显更高。这证明了积极的终身监测是合理的。
