Björk J, Akerbrant H, Iselius L, Alm T, Hultcrantz R
The Swedish Polyposis Registry, Dept. of Gastroenterology and Hepatology, Karolinska Hospital, Stockholm, Sweden.
Scand J Gastroenterol. 1999 Dec;34(12):1230-5. doi: 10.1080/003655299750024751.
The Swedish Polyposis Registry was set up in Sweden in the late 1950s to promote screening of familial adenomatous polyposis (FAP). The aim of this study was to examine the epidemiology of FAP in Sweden, including the influence of screening on morbidity and mortality in colorectal cancer (CRC).
Four hundred and thirty-one patients (213 males and 218 females) with FAP from 145 families recorded by the Swedish Polyposis Registry were investigated. The effect of screening on morbidity and mortality in CRC was evaluated by comparing the 216 probands with the 215 call-up patients. Three different periods were studied: the pre-screening period (1912-1956), the first screening period (1957-1976), and the second screening period (1977-1996).
The mean annual incidence rates during the three periods were 0.2, 1.38, and 0.86 per million, respectively. The birth frequency was calculated to be 1 in 18,000 between 1947 and 1966, and the prevalence was 32 per million at the end of 1996. The proportion of new mutants among the FAP patients born between 1927 and 1966 was estimated to be 11%. The median age at diagnosis of probands was 39 (range, 11-71) years and did not change over time, although an increase was seen in the subgroup with CRC at diagnosis (P = 0.02). In the call-up group the median age at diagnosis was 22 (range, 3-65) years. Sixty-seven per cent of the probands and 3.3% of the call-up patients had CRC at diagnosis, and the corresponding mortality figures were 44% and 1.9%. The risk among probands of having CRC at diagnosis decreased from 81% to 49% (P = 0.0006). Female probands were diagnosed with symptoms (P = 0.03) and CRC (P = 0.04) earlier than male probands.
A nationwide screening program facilitates detection and early diagnosis of FAP. A decrease in CRC morbidity among probands contributed to the improved prognosis. An earlier onset of symptoms and CRC in females indicate that the course of FAP is influenced by sex.
瑞典息肉病登记处于20世纪50年代末在瑞典设立，以促进家族性腺瘤性息肉病（FAP）的筛查。本研究的目的是调查瑞典FAP的流行病学情况，包括筛查对结直肠癌（CRC）发病率和死亡率的影响。
对瑞典息肉病登记处记录的145个家庭中的431例FAP患者（213例男性和218例女性）进行了调查。通过比较216例先证者和215例被召回患者，评估筛查对CRC发病率和死亡率的影响。研究了三个不同时期：筛查前期（1912 - 1956年）、首次筛查期（1957 - 1976年）和第二次筛查期（1977 - 1996年）。
三个时期的年平均发病率分别为每百万0.2、1.38和0.86。1947年至1966年间出生频率经计算为1/18000，1996年底患病率为每百万32。1927年至1966年间出生的FAP患者中新发突变体的比例估计为11%。先证者诊断时的中位年龄为39岁（范围11 - 71岁），且未随时间变化，尽管诊断时患有CRC的亚组有增加趋势（P = 0.02）。在被召回组中，诊断时的中位年龄为22岁（范围3 - 65岁）。67%的先证者和3.3%的被召回患者在诊断时患有CRC，相应的死亡率分别为44%和1.9%。先证者诊断时患CRC的风险从81%降至49%（P = 0.0006）。女性先证者比男性先证者更早出现症状（P = 0.03）和CRC（P = 0.04）。
全国性筛查计划有助于FAP的检测和早期诊断。先证者中CRC发病率的降低有助于改善预后。女性症状和CRC发病更早表明FAP的病程受性别影响。
