California Cancer Registry, Public Health Institute, Sacramento, CA 95825, USA.
J Natl Cancer Inst. 2011 Jul 20;103(14):1130-3. doi: 10.1093/jnci/djr207. Epub 2011 Jun 22.
Inaccurate coding of patients' Underlying Cause of Death (UCOD) has constrained cause-specific survival estimates for colon and rectal cancers. Using California data from the Accuracy of Cancer Mortality study, we compared the cancer site data from the California Cancer Registry (CCR) with UCODs reported on death certificates and reclassified the UCODs based on cancer registry data when they disagreed. We then calculated 1-, 3-, 5-, and 10-year cause-specific survival for colon and rectal cancers separately, before and after the reclassification. Records from 26 312 colon and 10 687 rectal cancer patients were examined. UCOD records disagreed with CCR records for 700 (6%) of 11 404 colon cancer deaths and with 1958 (39%) of 5011 rectal cancer deaths, and 82% of the misclassified rectal cancer deaths were coded as colon cancer deaths in the UCOD. Reclassification decreased cause-specific survival for both colon and rectal cancers, but the impact was more pronounced for rectal cancer (eg, 5-year cause-specific survival of colon cancer decreased by 2.8% and of rectal cancer decreased by 20.0% relative to previous estimates; absolute rates changed from 65.4% to 63.6%, and 81.2% to 64.9%, respectively, after reclassification). Interchangeable use of the terms colon cancer and colorectal cancer is likely to be one of the reasons for UCOD misclassification. Educational measures could improve the accuracy of UCOD for colon and rectal cancer deaths.
患者根本死因（UCOD）编码不准确限制了结肠癌和直肠癌的特定病因生存估计。利用来自癌症死亡率准确性研究（Accuracy of Cancer Mortality study）的加利福尼亚州数据，我们比较了加州癌症登记处（California Cancer Registry，CCR）的癌症部位数据与死亡证明报告的 UCOD，并在不一致时根据癌症登记处数据重新分类 UCOD。然后，我们分别计算了结肠癌和直肠癌在重新分类前后的 1 年、3 年、5 年和 10 年的特定病因生存。共检查了 26312 例结肠癌和 10687 例直肠癌患者的记录。11404 例结肠癌死亡中有 700 例（6%）和 5011 例直肠癌死亡中有 1958 例（39%）的 UCOD 记录与 CCR 记录不一致，82%的分类错误的直肠癌死亡被编码为 UCOD 中的结肠癌死亡。重新分类降低了结肠癌和直肠癌的特定病因生存率，但对直肠癌的影响更为明显（例如，5 年结肠癌特定病因生存率相对于之前的估计降低了 2.8%，直肠癌降低了 20.0%；绝对生存率分别从 65.4%变为 63.6%，从 81.2%变为 64.9%）。术语结肠癌和结直肠癌可互换使用可能是 UCOD 分类错误的原因之一。教育措施可以提高结肠癌和直肠癌死亡的 UCOD 准确性。
