Shaevitch Dana, Taghipour Sharareh, Miller Anthony B, Montgomery Neil, Harvey Bart
Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario M5T 3M7, Canada.
Department of Mechanical and Industrial Engineering, Ryerson University, Toronto, Ontario M5B 2K3, Canada.
J Cancer Res Ther. 2017 Jul-Sep;13(3):562-569. doi: 10.4103/0973-1482.174539.
This study set out to explore if breast cancers of different sizes are detected with varying sensitivity. In addition, we attempt to determine the effect of tumor size on screening detectability.
Data arising from the Canadian National Breast Screening Study (CNBSS) was used to perform all analyses. The CNBSS consists of two randomized controlled trials, which includes data on detection methods, age, and allocation groups. We stratified tumor size by 5 mm; age into 40-49 and 50-59 years age groups; and cancer detection or presentation methods into mammography only, physical breast examination only, both mammography and physical breast examination, interval cancers, and incident cancers.
This study revealed that a difference in tumor size exists for age (smaller tumor sizes are found in older women) and breast cancer detection or presentation modes. More specifically, breast cancers detected by mammography screening are statistically smaller than those detected by physical breast examination or those presenting as incident or interval cancers. This study also found that tumor size affects screening detectability for women in their 50's but not in their forties. That is, a statistically significant difference between mammography screening alone and physical examination alone was observed for women between the ages of 50-59 for tumor sizes up to 20 mm, including prevalent cases, and up to 15 mm when prevalent cases were excluded.
The results of this study suggest that smaller breast cancers are more likely to be detected among women in their 50s.
本研究旨在探讨不同大小的乳腺癌是否以不同的敏感性被检测到。此外，我们试图确定肿瘤大小对筛查可检测性的影响。
所有分析均使用来自加拿大国家乳腺筛查研究（CNBSS）的数据。CNBSS由两项随机对照试验组成，其中包括检测方法、年龄和分组的数据。我们将肿瘤大小按5毫米分层；年龄分为40 - 49岁和50 - 59岁年龄组；癌症检测或发现方法分为仅乳腺X线摄影、仅体格检查、乳腺X线摄影和体格检查两者、间期癌和新发癌。
本研究表明，在年龄（老年女性中发现的肿瘤较小）和乳腺癌检测或发现方式方面，肿瘤大小存在差异。更具体地说，通过乳腺X线摄影筛查检测到的乳腺癌在统计学上比通过体格检查检测到的或表现为新发或间期癌的乳腺癌更小。本研究还发现，肿瘤大小影响50多岁女性的筛查可检测性，但对40多岁的女性没有影响。也就是说，对于年龄在50 - 59岁的女性，在包括现患病例在内的肿瘤大小达20毫米时，以及排除现患病例时肿瘤大小达15毫米时，单独乳腺X线摄影筛查和单独体格检查之间在统计学上存在显著差异。
本研究结果表明，50多岁的女性更有可能检测到较小的乳腺癌。
