Levesque J, Bell R S, Coyte P C, Wright J G
Department of Surgery, Division of Orthopaedic Surgery, Room S107, The Hospital For Sick Children, 555 University Ave., Toronto, University of Toronto, ON, M5G 2X4, Toronto, Canada.
J Clin Epidemiol. 2001 Mar;54(3):225-31. doi: 10.1016/s0895-4356(00)00306-1.
Changing cancer rates, abstracted from tumor registries, are used to make inferences about the effect of carcinogens and cancer treatments on a population-wide basis. We compared the annual age-standardized incidence rates of extremity soft tissue sarcomas from two large tumor registries using different case definitions. We identified all limb soft tissue sarcoma cases diagnosed 1973-1993 in the Ontario Cancer Registry (OCR) and the Surveillance, Epidemiology, and End Results (SEER) databases. Two case definitions for limb soft tissue sarcoma were used based on missing data, incomplete diagnostic methods and ICD-9 codes; an upper limit estimate of the rates which included all possible cases of limb soft tissue sarcoma and a lower limit estimate of the rates which included all definite cases of limb soft tissue sarcoma (with the true rates lying in between). The upper limit OCR rates showed a statistically significant decreasing linear trend (slope = -0.021, P < 0.01). Whereas the slope of the OCR lower limit regression line showed a statistically significant increase in rates (slope = 0.01, P = 0.04). Neither the upper or lower limit SEER rates had a statistically significant linear trend (slope = 0.002, P = 0.60 and slope = 0.001, P = 0.18, respectively). Case definition affects incidence rates and changing rates of cancer. Thus the use of a single case definition along with changing coding practices may alone explain changing cancer rates.
从肿瘤登记处提取的癌症发病率变化情况，被用于推断致癌物和癌症治疗方法对整个人口的影响。我们使用不同的病例定义，比较了两个大型肿瘤登记处的四肢软组织肉瘤的年度年龄标准化发病率。我们在安大略癌症登记处（OCR）和监测、流行病学及最终结果（SEER）数据库中，确定了1973年至1993年期间诊断出的所有肢体软组织肉瘤病例。基于缺失数据、不完整的诊断方法和ICD - 9编码，我们使用了两种肢体软组织肉瘤的病例定义；一种是发病率的上限估计，包括所有可能的肢体软组织肉瘤病例；另一种是发病率的下限估计，包括所有明确的肢体软组织肉瘤病例（真实发病率介于两者之间）。OCR发病率上限呈现出具有统计学意义的线性下降趋势（斜率 = -0.021，P < 0.01）。而OCR发病率下限回归线的斜率显示发病率有统计学意义的上升（斜率 = 0.01，P = 0.04）。SEER发病率的上限和下限均无统计学意义的线性趋势（斜率分别为0.002，P = 0.60和斜率为0.001，P = 0.18）。病例定义会影响发病率和癌症发病率的变化。因此，仅使用单一的病例定义以及不断变化的编码方式，可能就解释了癌症发病率的变化。
