Nelson R L, Persky V, Turyk M
Department of Surgery, College of Medicine, University of Illinois at Chicago, USA.
J Surg Oncol. 1999 Jun;71(2):123-9. doi: 10.1002/(sici)1096-9098(199906)71:2<123::aid-jso13>3.0.co;2-c.
To determine if Americans of African origin (blacks) have less access to colonoscopic polypectomy than Americans of European origin (whites), the rate of carcinoma in situ of the colorectum (CIS), a disease more similar to benign adenoma of the colorectum than invasive cancer in its symptomatology, discovery, and treatment, was determined in the United States from 1973 to 1994. The hypothesis being tested is that CIS will be far less common in blacks than in whites and that rates of CIS should be increasing in whites from 1973 to 1994.
CIS and invasive carcinoma of the colorectum incidence data were obtained from Surveillance, Epidemiology, and End Results (SEER) Public Use Files from 1973 through 1994. Rates were age adjusted and proportions determined by division of CIS rates for each subsite by total carcinoma rates, for each year, race, and gender. The colorectum was divided anatomically in this analysis at the junction of the descending and sigmoid colon.
The relationships between male/female and black/white CIS incidence rates were broadly similar to invasive cancer rates over the 21 years of SEER, demonstrating a white male predominance for distal disease, a black male predominance for proximal disease, and a decline in incidence since 1988. CIS as a proportion of total colorectal cancer increased in all races and genders from 1973 to 1987, but then declined in all groups.
The majority of CIS is excised by endoscopic resection. Therefore, this might be considered a surrogate population for those individuals who have colonoscopic resection of benign adenomas. It is this latter treatment that has been hypothesized to be the cause for the declining incidence of invasive colorectal cancer. However, data presented herein do not support this hypothesis.
为了确定非洲裔美国人（黑人）接受结肠镜息肉切除术的机会是否少于欧洲裔美国人（白人），我们在美国测定了1973年至1994年期间结直肠癌原位癌（CIS）的发病率。原位癌在症状、发现和治疗方面比浸润性癌更类似于结直肠良性腺瘤。正在检验的假设是，CIS在黑人中比在白人中少见得多，并且1973年至1994年期间白人的CIS发病率应该在上升。
结直肠癌原位癌和浸润性癌的发病率数据来自1973年至1994年的监测、流行病学和最终结果（SEER）公共使用文件。发病率进行了年龄调整，每年、种族和性别的原位癌发病率比例通过各亚部位原位癌发病率除以总癌发病率来确定。在本分析中，结肠按解剖学在降结肠和乙状结肠交界处划分。
在SEER的21年中，男性/女性和黑人/白人原位癌发病率之间的关系与浸润性癌发病率大致相似，显示出远端疾病以白人男性为主，近端疾病以黑人男性为主，且自1988年以来发病率下降。从1973年到1987年，原位癌占结直肠癌总数的比例在所有种族和性别中均有所增加，但随后在所有组中均下降。
大多数原位癌通过内镜切除。因此，这可能被视为接受结肠镜下良性腺瘤切除术的人群的替代人群。正是后一种治疗方法被认为是浸润性结直肠癌发病率下降的原因。然而，本文提供的数据不支持这一假设。
