Departments of Clinical Effectiveness, The University of Texas MD Anderson Cancer Center, Houston, USA.
Am J Clin Oncol. 2011 Dec;34(6):573-80. doi: 10.1097/COC.0b013e3181fe41ed.
The objectives of the current study were to examine the trends in incidence rates of subsite-specific colorectal cancer at all stages in a large US population and to explore the impact of age and sex on colorectal cancer incidence.
Data were obtained from the Surveillance, Epidemiology, and End Results (SEER) 9 registries. Colorectal cancer incidence was divided into 3 anatomic subsite groupings: proximal colon, distal colon, and rectum. Incidence rates and relative risk were calculated using the SEER*Stat software provided by the National Cancer Institute.
From 1976 to 2005, age-adjusted incidence of proximal colon, distal colon, and rectal cancers per 100,000 population have steadily decreased from 22.5, 18.8, and 19.2 to 21.1, 11.7, and 13.6, respectively, contributing to the overall decline in the incidence of colorectal cancer from 60.5 to 46.4. Distal colon cancer had the greatest incidence decline (-37.79%), whereas the most minimal change in the incidence rates occurred for proximal colon cancer (-6.37%) because of increased incidence rates of ascending colon (24.8%) and hepatic flexure (21.3%) over 30 years. The steadily increased proportion of proximal colorectal cancer subsites was observed in both men and women starting at age 50 although women experienced a greater increase than did men.
Overall incidence rate of colorectal cancer decreased over the past 3 decades. The percent of ascending colon and hepatic flexure cancers diagnosed at early stages (localized and regional) increased. The finding on sex difference over years suggests that great attention should be paid in the future studies to male and female disparities.
本研究旨在探讨美国大型人群中各期结直肠肿瘤亚部位特异性发病率的变化趋势，并探讨年龄和性别对结直肠癌发病率的影响。
数据来源于监测、流行病学和最终结果（SEER）9 个登记处。结直肠癌发病率分为 3 个解剖亚部位分组：近端结肠、远端结肠和直肠。使用美国国家癌症研究所提供的 SEER*Stat 软件计算发病率和相对危险度。
1976 年至 2005 年，年龄校正后的近端结肠、远端结肠和直肠癌发病率每 10 万人分别从 22.5、18.8 和 19.2 降至 21.1、11.7 和 13.6，导致结直肠癌的总体发病率从 60.5 降至 46.4。远端结肠癌的发病率下降幅度最大（-37.79%），而近端结肠癌的发病率变化最小（-6.37%），原因是升结肠癌（24.8%）和肝曲结肠癌（21.3%）在 30 年内的发病率上升。在 50 岁以上的男性和女性中，近端结直肠肿瘤亚部位的比例逐渐增加，尽管女性的增加幅度大于男性。
在过去 30 年中，结直肠癌的总发病率呈下降趋势。诊断为早期（局部和区域）的升结肠癌和肝曲结肠癌比例增加。多年来的性别差异发现表明，未来的研究应特别关注男性和女性的差异。
