Ji B T, Devesa S S, Chow W H, Jin F, Gao Y T
Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, Maryland 20952, USA.
Cancer Epidemiol Biomarkers Prev. 1998 Aug;7(8):661-6.
Epidemiological characteristics of colorectal cancer may differ by particular anatomical subsite, suggesting that the subsite-specific colorectal cancers may represent different disease entities. This study explored the time trends over a 23-year period in colorectal cancer incidence at various subsites by sex and age group. Data on the incidence of colorectal cancer were obtained from a population-based cancer registry in Shanghai, People's Republic of China. Between 1972 and 1994, 30,693 patients with colorectal cancer were registered at the Shanghai Cancer Registry. The overall age-adjusted colorectal cancer incidence rates increased > 50%, or 2% per year from 1972-1977 to 1990-1994, from 14 to 22 per 100,000 among men and from 12 to 19 per 100,000 among women. The increases in rates were considerably more rapid for colon cancer, with rates approximately doubling, than they were for rectal cancer. Proximal colon cancer was more common than distal colon cancer over the whole study period, whereas rates for both cancers rose with similar annual percentage changes (> 5% per year) and across virtually all age groups. The estimated annual increases rose from 2% at ages 35-44 years to 7% at ages 75-84 years for proximal colon cancer, but they were more uniform for distal colon cancer (5-6% per year). Age-adjusted and age-specific rectal cancer rates changed little. The male:female age-adjusted rate ratio for colorectal cancer was 1.19 in 1990-1994. The ratios increased over time and varied by subsites, with ratios increasing from the proximal colon to the distal colon and to the rectum. Furthermore, men had higher rates than women for distal colon and rectal cancers at ages 55 and older, whereas women had higher rates than men at younger ages for these two cancers. Male:female rate ratios for proximal colon cancer did not vary substantially with age. The findings from this study indicate that subsite-specific incidence rates of colorectal cancer differ by sex and age and in their time trends. Cancers arising in the proximal colon, distal colon, and rectum may have somewhat different disease etiologies.
结直肠癌的流行病学特征可能因特定的解剖亚部位而异，这表明亚部位特异性结直肠癌可能代表不同的疾病实体。本研究探讨了23年间不同亚部位结直肠癌发病率按性别和年龄组划分的时间趋势。结直肠癌发病率数据来自中国上海市的一项基于人群的癌症登记处。1972年至1994年期间，上海癌症登记处登记了30693例结直肠癌患者。总体年龄调整后的结直肠癌发病率从1972 - 1977年到1990 - 1994年增加了50%以上，即每年增加2%，男性从每10万人14例增至22例，女性从每10万人12例增至19例。结肠癌发病率的增长速度明显快于直肠癌，结肠癌发病率几乎翻了一番。在整个研究期间，近端结肠癌比远端结肠癌更常见，而两种癌症的发病率以相似的年百分比变化（每年>5%）上升，且几乎在所有年龄组中都是如此。近端结肠癌估计的年增长率从35 - 44岁时的2%上升到75 - 84岁时的7%，但远端结肠癌更为一致（每年5 - 6%）。年龄调整和特定年龄的直肠癌发病率变化不大。1990 - 1994年结直肠癌的男性与女性年龄调整发病率之比为1.19。该比值随时间增加且因亚部位而异，从近端结肠到远端结肠再到直肠，比值逐渐增加。此外，55岁及以上男性远端结肠癌和直肠癌的发病率高于女性，而在较年轻年龄段，这两种癌症女性的发病率高于男性。近端结肠癌的男性与女性发病率之比随年龄变化不大。本研究结果表明，结直肠癌亚部位特异性发病率在性别、年龄及其时间趋势方面存在差异。发生在近端结肠、远端结肠和直肠的癌症可能具有 somewhat different disease etiologies。（此处原文“somewhat different disease etiologies”表述不太准确，可能是“有所不同的疾病病因”之意，但按照要求未作修改翻译）
