Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
Histopathology. 2023 Sep;83(3):453-464. doi: 10.1111/his.14966. Epub 2023 May 31.
The 8th Edition of the American Joint Committee on Cancer Staging System (yAJCC) excludes treatment-related fibrosis from the measurement of residual tumour after neoadjuvant chemotherapy (NAC) for breast cancer. The impact of the 8th Ed. yAJCC on post-NAC pathologic staging was examined in 188 breast cancer specimens from 183 patients with measurable residual tumour.
Tumour size, ypT, and ypN categories were reassessed with the current yACC criteria and compared to the original pathology reports. Histological patterns of response in the breast were categorised as concentric or scattered.
The reassessed breast tumour size or ypT category differed from the original report in 101 (53.7%) cases. Changes in the ypT and/or ypN category resulted in downstaging of 45/185 (24.3%). A smaller reassessed tumour size or lower ypT category occurred more often in hormone receptor-positive/HER2-negative (HR+/HER2-) (68.3%) and HER2-positive (HER2+) tumours (74.0%) than triple-negative breast cancer (TNBC) (37.5%) (P < 0.001). A scattered pattern of response was more frequent in HR+/HER2- (54.9%) and HER2+ (66.0%) tumours than TNBC (35.7%) (P = 0.006). Changes in size, ypT, or multifocality based on the 8th Ed. yAJCC criteria were more frequent in tumours with a scattered pattern of response (P < 0.001).
Strict adherence to yAJCC criteria for measurement of the residual breast tumour after NAC resulted in smaller tumour size, lower ypT category, lower yAJCC stage, and more frequent classification of residual tumour as multifocal. Downstaging based on 8th Ed. yAJCC criteria was associated with tumour subtype and histological pattern of response.
第 8 版美国癌症联合委员会（AJCC）分期系统（yAJCC）将新辅助化疗（NAC）后乳腺癌残留肿瘤的测量排除在治疗相关纤维化之外。本研究在 183 例可测量残留肿瘤患者的 188 例乳腺癌标本中，检查了第 8 版 yAJCC 对 NAC 后病理分期的影响。
使用当前的 yACC 标准重新评估肿瘤大小、ypT 和 ypN 分类，并与原始病理报告进行比较。将乳腺组织学反应模式分为同心或散射。
在 101 例（53.7%）病例中，重新评估的乳腺肿瘤大小或 ypT 分类与原始报告不同。ypT 和/或 ypN 分类的改变导致 45/185（24.3%）病例降期。激素受体阳性/HER2 阴性（HR+/HER2-）（68.3%）和 HER2 阳性（HER2+）肿瘤（74.0%）比三阴性乳腺癌（TNBC）（37.5%）（P<0.001）中更常出现较小的重新评估肿瘤大小或较低的 ypT 分类。HR+/HER2-（54.9%）和 HER2+（66.0%）肿瘤比 TNBC（35.7%）（P=0.006）更常出现散射反应模式。根据第 8 版 yAJCC 标准，大小、ypT 或多灶性的改变在散射反应模式的肿瘤中更为常见（P<0.001）。
严格遵循 yAJCC 标准测量 NAC 后残留乳腺肿瘤的大小导致肿瘤体积更小、ypT 分类更低、yAJCC 分期更低，并且更常将残留肿瘤分类为多灶性。基于第 8 版 yAJCC 标准的降期与肿瘤亚型和组织学反应模式相关。
