Bülow C, Vasen H, Järvinen H, Björk J, Bisgaard M L, Bülow S
Danish Polyposis Register, Hvidovre University Hospital, Copenhagen, Denmark.
Gastroenterology. 2000 Dec;119(6):1454-60. doi: 10.1053/gast.2000.20180.
BACKGROUND & AIMS: This study reevaluates the risk of rectal cancer and the frequency of subsequent proctectomy for nonmalignant causes in patients with familial adenomatous polyposis (FAP) who have undergone colectomy with ileorectal anastomosis (IRA). Potential risk factors for rectal cancer in this setting are also examined, and recommendations for the choice of surgical procedure are made.
The national polyposis registries in Denmark, Finland, The Netherlands, and Sweden included 659 patients undergoing surgery with IRA in 1940-1997. Kaplan-Meier analysis and Cox regression analysis were performed to evaluate cumulative risk, survival, and predictive risk factors.
Rectal carcinoma was diagnosed in 47 patients, with a cumulative 40-year risk of 0.32. The cumulative risk according to chronologic age was 0.30 at age 60, and higher in patients undergoing surgery above age 25 (P = 0.0016). Chronologic age was the only independent risk factor (P = 0.0016). The cumulative 5-year survival rate after rectal carcinoma was 0.60. The apc mutation was known in 167 patients, of whom 7 had rectal cancer. The cumulative 40-year risk of secondary proctectomy was 0.70, and higher in patients with a mutation in codon 1250-1500 than outside this region (P = 0.005). However, all 7 rectal cancers were found in the latter group. None of the 18 patients with attenuated FAP (mutation in codon 0-200 or >1500) had a secondary proctectomy.
IRA is recommended in (1) young patients with few rectal adenomas and a family history of a mild phenotype and (2) patients with attenuated FAP (a mutation in codon 0-200 or >1500), provided there is acceptance of life-long rectal surveillance. Patients with many rectal polyps and/or a family history of severe polyposis should be offered a restorative proctocolectomy with an ileal pouch-anal anastomosis.
本研究重新评估了接受回肠直肠吻合术（IRA）结肠切除术的家族性腺瘤性息肉病（FAP）患者患直肠癌的风险以及因非恶性原因进行后续直肠切除术的频率。还研究了这种情况下直肠癌的潜在危险因素，并对手术方式的选择提出建议。
丹麦、芬兰、荷兰和瑞典的国家息肉病登记处纳入了1940年至1997年间接受IRA手术的659例患者。采用Kaplan-Meier分析和Cox回归分析来评估累积风险、生存率和预测风险因素。
47例患者被诊断为直肠癌，40年累积风险为0.32。按实足年龄计算，60岁时累积风险为0.30，25岁以上接受手术的患者风险更高（P = 0.0016）。实足年龄是唯一的独立危险因素（P = 0.0016）。直肠癌后的5年累积生存率为0.60。167例患者已知有腺瘤性息肉病（APC）突变，其中7例患有直肠癌。二次直肠切除术的40年累积风险为0.70，密码子1250 - 1500发生突变的患者高于该区域以外的患者（P = 0.005）。然而，所有7例直肠癌均在后者组中发现。18例轻度FAP（密码子0 - 200或>1500发生突变）患者均未进行二次直肠切除术。
对于（1）直肠腺瘤少且有轻度表型家族史的年轻患者，以及（2）轻度FAP（密码子0 - 200或>1500发生突变）患者，若接受终身直肠监测，建议采用IRA。对于直肠息肉多和/或有严重息肉病家族史的患者，应提供回肠储袋肛管吻合术的恢复性直肠结肠切除术。
