Wray Charlie M, Ziogas Argyrios, Hinojosa Marcelo W, Le Hoa, Stamos Michael J, Zell Jason A
College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, California, USA.
Dis Colon Rectum. 2009 Aug;52(8):1359-66. doi: 10.1007/DCR.0b013e3181a7b7de.
Proximal colon cancers are more likely to present with advanced stage than distal cancers; however, previous reports conflict regarding the independent prognostic significance of tumor location on survival. We examined survival by colon cancer subsite location by use of data from the California Cancer Registry.
An analysis of colon cancer cases from 1994 to 2004 was conducted, with follow-up through 2006. Colon subsite location was defined as proximal colon (cecum, ascending colon, hepatic flexure), transverse colon, descending colon (splenic flexure, descending colon), and sigmoid colon. Subsite-specific survival analyses were conducted with use of the Kaplan-Meier method and Cox proportional hazards ratios.
A total of 82,926 colon cancer cases were identified, including 40,078 proximal (48%), 8,023 transverse (10%), 8,657 descending (10%), and 26,168 sigmoid cancers (32%). A larger proportion of sigmoid cancers (30.5%) presented as Stage I compared with proximal (18.5%), transverse (16.8%), or descending colon cancers (20.1%). Proximal cancers had the greater proportion with high tumor grade (27%), and had a greater mean number of lymph nodes examined. There were no differences in treatment rendered when each colon subsite was stratified by stage. After adjustment for stage, grade, treatment, lymph node examination, and other relevant clinical variables, sigmoid cancers had decreased colorectal cancer-specific mortality compared with proximal tumors (hazards ratio = 0.88; 95% confidence interval, 0.85-0.92).
In this analysis, sigmoid colon cancers were observed to have earlier stage, lower tumor grade, and independently decreased colorectal cancer-specific mortality compared with proximal tumors.
近端结肠癌比远端结肠癌更易出现晚期；然而，先前的报告在肿瘤位置对生存的独立预后意义方面存在冲突。我们利用加利福尼亚癌症登记处的数据，按结肠癌亚部位分析了生存率。
对1994年至2004年的结肠癌病例进行分析，并随访至2006年。结肠亚部位定义为近端结肠（盲肠、升结肠、肝曲）、横结肠、降结肠（脾曲、降结肠）和乙状结肠。采用Kaplan-Meier法和Cox比例风险比进行亚部位特异性生存分析。
共识别出82926例结肠癌病例，包括40078例近端结肠癌（48%）、8023例横结肠癌（10%）、8657例降结肠癌（10%）和26168例乙状结肠癌（32%）。与近端结肠癌（18.5%）、横结肠癌（16.8%）或降结肠癌（20.1%）相比，更大比例的乙状结肠癌（30.5%）表现为I期。近端结肠癌高肿瘤分级的比例更高（27%），且平均检查的淋巴结数量更多。按分期对每个结肠亚部位进行分层时，治疗方面无差异。在对分期、分级、治疗、淋巴结检查及其他相关临床变量进行调整后，与近端肿瘤相比，乙状结肠癌的结直肠癌特异性死亡率降低（风险比=0.88；95%置信区间，0.85-0.92）。
在本分析中，观察到乙状结肠癌与近端肿瘤相比，分期更早、肿瘤分级更低，且结直肠癌特异性死亡率独立降低。
