肿瘤浸润淋巴细胞（TILs）被认为是乳腺癌肿瘤微环境中的关键参与者，但是病理医生之间存在较大的观察者间的差异，阻碍了其作为生物标志物的应用。我们开发了一种基于深度学习（DL）的TIL分析器，用于评估乳腺癌中的间质TIL（sTILs）。三名病理学家评估了402个乳腺癌全切片图像，并解读了sTIL评分。DL模型在210个显示sTIL评分差异小于10个百分点的病例（52.2％）中进行了独立的性能评估，与病理医生的评分相比，得到了0.755的一致性相关系数（95％置信区间[CI]，0.693-0.805）。对于226个显示病理医生评分与DL模型之间存在10个百分点或更大差异的切片（56.2％），进行了修订。DL辅助下不一致的病例数量降至116个（28.9％）（p < 0.001）。DL辅助还增加了每两名病理学家之间sTIL评分的一致性相关系数。在经新辅助化疗的三阴性和人类表皮生长因子受体2（HER2）阳性乳腺癌患者中，DL辅助修订明显强调了对应者的更高sTIL评分（26.8 ± 19.6 vs. 19.0 ± 16.4，p = 0.003）。此外，DL辅助修订揭示了sTIL高表达肿瘤（sTIL ≥ 50）与化疗反应的相关性（奇异比1.28 [95％置信区间，1.01-1.63]，p = 0.039）。通过提高病理学家之间sTIL解读的一致性，并预测新辅助化疗反应，在这里我们报道了DL工具作为乳腺癌评估中sTIL评分的参考价值。 © 2023. Springer Nature Limited.

Tumor-infiltrating lymphocytes (TILs) have been recognized as key players in the tumor microenvironment of breast cancer, but substantial interobserver variability among pathologists has impeded its utility as a biomarker. We developed a deep learning (DL)-based TIL analyzer to evaluate stromal TILs (sTILs) in breast cancer. Three pathologists evaluated 402 whole slide images of breast cancer and interpreted the sTIL scores. A standalone performance of the DL model was evaluated in the 210 cases (52.2%) exhibiting sTIL score differences of less than 10 percentage points, yielding a concordance correlation coefficient of 0.755 (95% confidence interval [CI], 0.693-0.805) in comparison to the pathologists' scores. For the 226 slides (56.2%) showing a 10 percentage points or greater variance between pathologists and the DL model, revisions were made. The number of discordant cases was reduced to 116 (28.9%) with the DL assistance (p < 0.001). The DL assistance also increased the concordance correlation coefficient of the sTIL score among every two pathologists. In triple-negative and human epidermal growth factor receptor 2 (HER2)-positive breast cancer patients who underwent the neoadjuvant chemotherapy, the DL-assisted revision notably accentuated higher sTIL scores in responders (26.8 ± 19.6 vs. 19.0 ± 16.4, p = 0.003). Furthermore, the DL-assistant revision disclosed the correlation of sTIL-high tumors (sTIL ≥ 50) with the chemotherapeutic response (odd ratio 1.28 [95% confidence interval, 1.01-1.63], p = 0.039). Through enhancing inter-pathologist concordance in sTIL interpretation and predicting neoadjuvant chemotherapy response, here we report the utility of the DL-based tool as a reference for sTIL scoring in breast cancer assessment.© 2023. Springer Nature Limited.