Cancer Registry of Norway, Oslo, Norway.
Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.
Acta Oncol. 2020 Mar;59(3):260-267. doi: 10.1080/0284186X.2019.1669817. Epub 2019 Sep 30.
Women diagnosed with breast cancer are offered treatment and therapy based on tumor characteristics, including tumor diameter. There is scarce knowledge whether tumor diameter is accurately reported, or whether it is unconsciously rounded to the nearest half-centimeter (terminal digit preference). This study aimed to assess the precision (number of digits) of breast cancer tumor diameters and whether they are affected by terminal digit preference. Furthermore, we aimed to assess the agreement between mammographic and histopathologic tumor diameter measurements. This national registry study included reported mammographic and registered histopathologic tumor diameter information from the Cancer Registry of Norway for invasive breast cancers diagnosed during 2012-2016. Terminal digit preference was assessed using histograms. Agreement between mammographic and histopathologic measurements was assessed using the intraclass correlation coefficient (ICC) and Bland-Altman plots. Mammographic, histopathologic, or both tumor measurements were available for 7792, 13,541 and 6865 cases, respectively. All mammographic and 97.2% of histopathologic tumor diameters were recorded using whole mm. Terminal digits of zero or five were observed among 38.7% and 34.8% of mammographic and histopathologic measurements, respectively. There was moderate agreement between the two measurement methods (ICC = 0.52, 95% CI: 0.50-0.53). On average, mammographic measurements were 1.26 mm larger (95% limits of agreement: -22.29-24.73) than histopathologic measurements. This difference increased with increasing tumor size. Terminal digit preference was evident among breast cancer tumor diameters in this nationwide study. Further studies are needed to investigate the potential extent of under-staging and under-treatment resulting from this measurement error.
被诊断患有乳腺癌的女性会根据肿瘤特征（包括肿瘤直径）接受治疗和疗法。目前尚不清楚肿瘤直径是否准确报告，或者是否无意识地四舍五入到最接近的半厘米（尾数偏好）。本研究旨在评估乳腺癌肿瘤直径的精度（数字位数），以及它们是否受到尾数偏好的影响。此外，我们旨在评估乳腺摄影和组织病理学肿瘤直径测量之间的一致性。这项全国性注册研究包括 2012 年至 2016 年间诊断的浸润性乳腺癌患者的挪威癌症登记处报告的乳腺摄影和登记的组织病理学肿瘤直径信息。尾数偏好使用直方图进行评估。使用组内相关系数（ICC）和 Bland-Altman 图评估乳腺摄影和组织病理学测量之间的一致性。分别有 7792、13541 和 6865 例患者的乳腺摄影、组织病理学或两者的肿瘤测量值可用。所有乳腺摄影和 97.2%的组织病理学肿瘤直径均以全毫米记录。在乳腺摄影和组织病理学测量中，尾数为零或五的分别占 38.7%和 34.8%。两种测量方法之间的一致性中等（ICC=0.52，95%置信区间：0.50-0.53）。平均而言，乳腺摄影测量值比组织病理学测量值大 1.26 毫米（95%置信区间：-22.29-24.73）。这种差异随着肿瘤大小的增加而增加。在这项全国性研究中，乳腺癌肿瘤直径存在尾数偏好。需要进一步研究以调查由于这种测量误差导致的潜在分期不足和治疗不足的程度。
