Clarke Christina A, Undurraga Dawn M, Harasty Patricia J, Glaser Sally L, Morton Lindsay M, Holly Elizabeth A
Northern California Cancer Center, Fremont, CA 94538, USA.
Cancer Epidemiol Biomarkers Prev. 2006 Apr;15(4):630-8. doi: 10.1158/1055-9965.EPI-05-0549.
Because lymphoma comprises numerous histologic subtypes, understanding the reasons for ongoing increases in its incidence requires surveillance and etiologic study of these subtypes. However, this research has been hindered by many coexisting classification schemes. The Revised European American classification of Lymphoid Neoplasms (REAL)/WHO system developed in 1994 and now used in clinical settings was not incorporated into the International Classification of Diseases-Oncology (ICD-O), used by cancer registries, until the release of the third edition (ICD-O-3) in 2001. Studies including patients diagnosed before 2001 may have codes from earlier ICD-O versions that must be converted to ICD-O-3 and have higher proportions of unclassified (e.g., lymphoma and not otherwise specified) cases. To better understand (a) the agreement of computer-converted ICD-O-3 codes to ICD-O-3 codes generated directly from diagnostic pathology reports and (b) the reproducibility of unclassified status, we reviewed a population-based series of diagnostic pathology reports for lymphoma patients diagnosed before (1988-1994; n = 1,493) and after (1998-2000; n = 1,527) the REAL/WHO scheme was introduced. Overall, computer- and coder-assigned ICD-O-3 codes agreed for 77% of patients in both groups and improved slightly (82%) when codes were grouped. The most common lymphoma subtypes, diffuse large B cell and follicular, had relatively good reliability (84-89%) throughout the study period. T-cell and natural killer cell lymphomas had worse agreement than B-cell lymphomas, even when grouped. Many (42-43%) lymphomas reported as unclassifiable could be assigned a subtype upon pathology report review. These findings suggest that the study of lymphoma subtypes could be improved by (a) use of more standardized terminology in pathology reports, (b) grouping individual ICD-O-3 codes to reduce misclassification bias, and (c) routine secondary editing of unclassified lymphomas by central cancer registries.
由于淋巴瘤包含众多组织学亚型，要理解其发病率持续上升的原因，就需要对这些亚型进行监测和病因学研究。然而，这项研究受到多种并存分类方案的阻碍。1994年制定并现用于临床的《欧美淋巴瘤修订分类（REAL）/世界卫生组织（WHO）系统》，直到2001年第三版《国际疾病分类-肿瘤学（ICD-O-3）》发布才被纳入癌症登记处使用的ICD - O中。包括2001年以前诊断患者的研究可能使用的是早期ICD - O版本的编码，这些编码必须转换为ICD - O-3，且未分类（如淋巴瘤，未另行说明）病例的比例更高。为了更好地理解（a）计算机转换的ICD - O-3编码与直接从诊断病理报告生成的ICD - O-3编码的一致性，以及（b）未分类状态的可重复性，我们回顾了一系列基于人群的淋巴瘤患者诊断病理报告，这些患者分别在REAL/WHO方案引入之前（1988 - 1994年；n = 1493）和之后（1998 - 2000年；n = 1527）被诊断。总体而言，两组中77%的患者计算机和编码员分配的ICD - O-3编码一致，编码分组后一致性略有提高（82%）。在整个研究期间，最常见的淋巴瘤亚型弥漫性大B细胞淋巴瘤和滤泡性淋巴瘤具有相对较好的可靠性（84 - 89%）。T细胞和自然杀伤细胞淋巴瘤的一致性比B细胞淋巴瘤差，即使进行了分组。经病理报告复查，许多报告为不可分类的淋巴瘤（42 - 43%）可以确定亚型。这些发现表明，通过（a）在病理报告中使用更标准化的术语，（b）对单个ICD - O-3编码进行分组以减少错误分类偏差，以及（c）癌症中央登记处对未分类淋巴瘤进行常规二次编辑，可改进淋巴瘤亚型的研究。
