Professor of Surgery (Emeritus), Harvard Medical School, Boston, MA, USA.
Professor of Surgery (Emeritus), Warren Alpert Medical School of Brown University, Providence, USA.
Breast Cancer Res Treat. 2020 Nov;184(1):135-147. doi: 10.1007/s10549-020-05834-9. Epub 2020 Aug 10.
Controversy exists regarding proportional contributions of mammographic screening versus systemic therapy to declining disease-specific mortality of female invasive breast cancer (IBC) in the United States. Understanding relative contributions may help address allocation of medical resources.
A 31-year (1987-2017) review of Rhode Island (RI) Cancer Registry data of female IBC was carried out in a state with high rates of mammographic screening.
Over 31 years in RI, statistically significant improvements occurred at initial diagnosis of IBC: mean and median maximum cancer diameters decreased by 21% and 30% respectively. Despite 1997 introduction of more accurate sentinel lymph node biopsy, the proportion of patients with axillary lymph node metastases (LNM) decreased by 27%. Extent of LNM also decreased as patients with over three node metastases decreased 67%. By 2017, 53% of all patients with LNM had only one. Poorly differentiated cancers decreased 50%. Disease-specific mortality decreased 57%.
Improvements in initial presentation of IBC are consistent with most having progressive growth, from cellular origin to palpable mass, the currently accepted biological model. Breast cancers identified earlier at initial diagnosis through screening mammography are characterized by smaller size, fewer axillary LNMs, better grade differentiation, and decreased mortality. Statistical analysis from these improved diagnostic parameters indicate that the majority of mortality decline from invasive breast cancer in RI can be attributed to earlier detection. Thus, mammography predominates in preventing mortality.
在美国，关于乳腺筛查与全身治疗对女性浸润性乳腺癌（IBC）疾病特异性死亡率下降的比例贡献存在争议。了解相对贡献可能有助于解决医疗资源的分配问题。
对罗德岛（RI）癌症登记处的女性 IBC 数据进行了为期 31 年（1987-2017 年）的回顾性研究，该州的乳腺筛查率很高。
在 RI 超过 31 年的时间里，IBC 的初始诊断发生了统计学意义上的显著改善：最大癌症直径的平均值和中位数分别下降了 21%和 30%。尽管 1997 年引入了更准确的前哨淋巴结活检，但腋窝淋巴结转移（LNM）患者的比例下降了 27%。随着转移至三个以上淋巴结的患者减少了 67%，LNM 的范围也有所减少。到 2017 年，所有 LNM 患者中有 53%仅存在一处转移。低分化癌症减少了 50%。疾病特异性死亡率下降了 57%。
IBC 初始表现的改善与大多数从细胞起源到可触及肿块的渐进性生长相一致，这是目前公认的生物学模型。通过筛查性乳房 X 光检查在初始诊断时更早发现的乳腺癌，其特征是体积更小、腋窝淋巴结转移（LNM）更少、分化程度更好，死亡率降低。这些改进的诊断参数的统计分析表明，RI 浸润性乳腺癌死亡率的大部分下降可归因于早期发现。因此，乳腺 X 光检查在预防死亡率方面占主导地位。
