Background: Pyrotinib, a newly-developed irreversible pan-ErbB inhibitor, has shown promising antitumor activity and acceptable tolerability in phase 1-3 studies. However, findings from randomized clinical trials may have limited generalizability to patients treated in routine clinical practice. Herein, we conducted this multicenter real-world study to examine the treatment patterns, effectiveness and safety of pyrotinib-based therapy in human epidermal growth factor receptor 2 (HER2)-positive breast cancer (BC) patients in China.Methods: This is a China-based, observational study of HER2-positive BC patients receiving pyrotinib-based therapy (NCT04158505). Both early stage and advanced disease were included. Demographics, treatment patterns, and diarrhea management were summarized. The data cutoff date was April 30, 2021, and the study is ongoing to enroll. Real-world progression-free survival (PFS) and overall survival (OS) will be analyzed. Results: Between October 2019 and April 2021, a total of 907 patients (45 in the neoadjuvant setting [median age, 51 years] and 862 in the advanced setting [median age, 54 years]) from 65 sites received at least one dose of pyrotinib. Considering the limited sample size of early stage patients so far, we focused on advanced BC patients in this report. Of 862 patients with advanced disease, 44.2% had visceral metastases, 12.5% had brain metastases, 31.1%, 35.7%, and 33.2% received pyrotinib-based therapy as first-line, second-line, and third- or later-line treatment, respectively. The majority of patients (82.5%) were trastuzumab-exposed, and 10.2% were lapatinib-treated before receiving pyrotinib. Among 744 patients with available treatment information, 75.8% started with standard dose of pyrotinib (400 mg). Pyrotinib plus capecitabine (372 [50.0%]) was the most commonly used regimen for advanced disease, followed by pyrotinib plus chemotherapy other than capecitabine (189 [25.4%]), pyrotinib plus trastuzumab and chemotherapy (100 [13.4%]), and pyrotinib alone (77 [10.3%]). At the time of data cutoff, there were 164 (19.0%) progression or death events in 862 patients with advanced disease, and the median PFS and OS was not mature for the whole population. The median PFS for patients receiving second-line pyrotinib-based therapy was 11.7 months (95% CI, 8.8-not reached). The most common adverse event was diarrhea. Any grade and grade ≥3 diarrhea occurred in 70.5% and 14.9% of 907 patients, respectively. Diarrhea in eight (0.9%) patients with advanced disease were deemed as serious adverse events. Eighty-nine (9.8%) patients received diarrhea prophylaxis, and 436 (48.1%) used antidiarrhea drugs after diarrhea occurred. Montmorillonite powder (6.0% and 33.6%) were the most commonly used drug for both diarrhea prophylaxis and treatment, followed by loperamide (3.9% and 27.9%).Conclusions: In real world, a high percentage of physicians chose to use pyrotinib-based therapy in front lines when treating HER2-positive advanced BC patients, which might maximize its antitumor activity. Diarrhea is manageable in the real-world setting. Citation Format: Yiqun Li, Zhongsheng Tong, Quchang Ouyang, Xinhong Wu, Wei Li, Li Cai, Zhiyong Yu, Zhengxiang Han, Xiaojia Wang, Man Li, Jin Yang, Li Li, Zhaofeng Niu, Haibo Wang, Qitang Wang, Yi Li, Yuee Teng, Shiguang Zhu, Binghe Xu. Treatment patterns and adverse events of pyrotinib-based therapy in HER2-positive breast cancer patients in China: Results from a multicenter, real-world study [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P2-13-40.

virus cellular receptor 2 (HAVCR2), is a negative immune checkpoint mole cule expressed on a variety of immune cells including T cells [5], dendritic cells [6], and macrophages [7]. Accumulating evidence demonstrate that Tim-3 can reduce cell proliferation, decrease the production of effective cytokines and increase apoptosis of effector T cells, through interaction with its ligands including galectin-9, high mobility group protein B1 (HMGB1), carcinoembryonic antigen related cell adhesion molecule 1 (CEACAM-1) and phosphatidylserine [8,9].Tim-3 is now considered as a critical mediator in cancer pro gression and attracts considerable attention as a therapeutic target. Blocking Tim-3 indeed shows some promising results in multiple preclinical cancer models [10]. More importantly, there is evidence suggesting that resistance to anti-CTLA-4 (cytotoxic T-lymphocyte-associated antigen 4) or anti-PD-1/PD-L1 inhibitors is partially by compensatory upregulation of additional immune checkpoints including Tim-3 [11]. And co-blockade of PD-1 and Tim-3 shows a significant survival advantage in a lung cancer mouse model [12]. These findings support the view that Tim-3 may be a potential target for tumour therapy.Interestingly, Tim-3 is not only expressed on immune cells but also overexpressed on many types of malignant tumours. In vitro findings revealed that Tim-3 promoted metastasis of esophageal squamous cell carcinoma (ESCC) by inducing epithelial-mesenchymal transition (EMT) via the Akt/GSK-3/Snail signalling pathway. Tim-3 knockdown markedly inhibited proliferation, migration, and invasion of ESCC cell lines [13]. Additionally, Interfering Tim-3 expression can significantly suppress osteosarcoma cell proliferation and metastasis via the NF-κB/Snail signalling pathway and EMT [14].Recently, a study in liver cancer indicated that tumour cell-intrinsic Tim-3 promotes cell proliferation via the NF-κB/IL-6/STAT3 cascade signalling axis [15]. Clinically, The ectopic expression of Tim-3 in tumour cells were correlated with more advanced pathologic T classification in non-small-cell lung carcinoma [16], lymph-vascular invasion in gastric cancer [17], lung metastasis in clear cell renal cell carcinoma [18], and lymphatic metastasis in colon cancer [9]. A meta-analysis revealed that higher expression of Tim-3 in solid tumours had significantly shorter overall survival [19]. Therefore, Tim-3 has been depicted as a prognostic indicator for those cancer patients. But contradictory results were also reported in terms of the role of Tim-3. Down-regulated Tim-3 promotes invasion and metastasis

Objective: Benign breast disease (BBD), especially benign proliferative breast disease (BPBD), is related to increased breast cancer risk. However, few studies have examined whether conventional breast cancer risk factors influence risk of breast cancer among women with BBD. The aim of this study was to evaluate the associations of lifestyle factors with risk of breast cancer among women biopsied for BBD within a multi-center, hospital-based, case-control study in China, in order to provide scientific basis of health guidance for BBD patients and lay the foundation for primary prevention of breast cancer. Methods: A multi-center, hospital-based, case-control study was conducted. Patients with BPBD (n=608) and patients with non-proliferative breast disease (NPBD) (n=366) were collected from 23 hospitals in 11 provinces during April 2012 to April 2013. A face-to-face survey, baseline data and fasting blood was collected with all study subjects. Serum adiponectin levels were assayed using ELISA. After 10 years, the cumulative incidence rate of breast cancer in the two groups was counted through follow-up. Logistic regression analysis was used to obtain the association between specific factors and risk of breast cancer. Results: After 10 years’ follow-up, 388 BPBD and 240 NPBD cases were included in the final analysis (Table 1), of which 16 (4.12%) and 3 (1.25%) developed breast cancer, respectively. The cumulative incidence of breast cancer between the two groups was significant difference (P=0.041). Compared with women in the NPBD group, BPBD group were more likely to be central obesity (with higher waist-to-hip ratio (WHR)) (OR 24.98, 95% CI 1.845-336.203, P=0.015) and less likely to have physical activity (OR 0.626, 95% CI 0.416-0.943, P=0.025) and less often to eat carrots (OR 0.616, 95% CI 0.398-0.953, P=0.030) (Table 2). Subgroup analyze indicated that, physical activity, eat carrots and ham sausage, body weight, BMI, waist circumference and WHR were statistical differences in premenopausal BPBD patients, while only physical activity (OR 0.423, 95% CI 0.269-0.665 P < 0.001) was the independent risk factors. Meanwhile, among the factors of Tea consumption, Glycemia, Body weight, BMI, Waist circumference, WHR and HMW/total adiponectin ratio in postmenopausal group, only HMW/total adiponectin ratio (OR 0.041, 95% CI 0.002-0.820 P=0.037) was statistically significant factor. These stratified multivariate logistic regression analysis results are shown in Table 3. Conclusion: In patients with BBD, physical activity may be the protect factor for breast cancer carcinogenesis in premenopausal women while lower HMW/total adiponectin ratio is a risk factor for postmenopausal women, which can provide direction for primary prevention of breast cancer. Table 1. Pathological types of all subjects. Table 2. The results of multivariate Logistic regression analysis. Table 3. Stratified multivariate Logistic regression analysis by menopause status. Citation Format: Chao Zheng, Dandan Ma, Linfeng Zhao, Maolin Guo, Shude Cui, Fuguo Tian, Zhimin Fan, Cuizhi Geng, Xuchen Cao, Zhenlin Yang, Xiang Wang, Hong Liang, Shu Wang, Hongchuan Jiang, Xuening Duan, Haibo Wang, Guolou Li, Qitang Wang, Jianguo Zhang, Feng Jin, Jinhai Tang, Liang Li, Shi-Guang Zhu, Wenshu Zuo, Fei Wang, Lixiang Yu, Fei Zhou, Yujuan Xiang, Mingming Guo, Yongjiu Wang, Wenzhong Zhou, Shuya Huang, Zhaohui Li, Yajie Zhou, Lijuan Hou, Xinyi Yang, Xuan Zhang, Liyuan Liu, Zhigang Yu. Lifestyle factors are associated with breast cancer risk in women biopsied for benign breast diseases in China: 10-year results of a multi-center, hospital-based, case-control study [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P4-03-31.

Background: As a first-echelon nodal drainage site of breast cancer, the status of axillary lymph nodes (ALN) and internal mammary lymph nodes (IMLN) is both valuable for regional staging and treatment choice. The internal mammary sentinel lymph node biopsy (IM-SLNB) may provide minimally invasive staging, and guide individual IMLN radiation. Modified technique (periareolar intraparenchymal, high volume and ultrasound guidance) got a high internal mammary sentinel lymph nodes (IM-SLN) visualization rate of 71.1% in single center, and the prospective multicenter study was designed to verify its repeatability (CBCSG026, NCT03541278). High visualization rate and low false negative rate are prerequisites for the widespread of IM-SLNB. The question arises as to whether IM-SLN detected with the modified technique should be considered as “true” IM-SLN. The prospective, multicenter, clinical validation study of IM-SLNB followed by internal mammary lymph node dissection (IM-LND) was designed to verify the accuracy of IM-SLNB in patients with ALN positive breast cancer (CBCSG027, NCT03024463). Methods: While CBCSG026 trial enrolled patients with both axillary negative and positive breast cancer, CBCSG027 trial only enrolled axillary positive patients receiving mastectomy (either biopsy proving cN+ disease or cN0 with positive axillary SLN). The 1st to 3rd intercostal IM-LND was performed immediately after IM-SLNB to verify its accuracy in the CBCSG027 trial. Result: From May 2018 to June 2022, 600 and 264 patients were enrolled in the CBCSG026 and CBCSG027 trial from seven centers in China, respectively. Among the 600 recruited patients in the CBCSG026, the IM-SLN visualization rate was 65.0% (390/600), which was significantly related to patient’s age, body mass index, radiotracer intensity and interval time between injection and IM-SLN identification (all P< 0.05). The IM-SLNB successful rate was 97.4% (380/390), and the complication was 6.9%. The median number of IM-SLN was 1. The overall IM-SLN metastases rate was 18.9% (72/380), with 33.0% (65/195) and 3.8% (7/185) in ALN positive and negative patients, respectively. Multivariate analysis showed that the tumor size (P=0.028), the tumor location (P< 0.001) and the number of positive ALNs (P< 0.001) were independent predictors of IM-SLN metastasis. Those variables were included in a novel nomogram (Table 1), which was significantly better than the probability based on the number of metastatic ALNs alone according to the current guidelines (area under the curve: 0.860 vs. 0.804, P< 0.001). Of the 264 patients enrolled in the CBCSG027 trial, 185 patients (70.1%) had IM-SLN visualization (included 107 with cN+ disease and 78 with positive axillary SLN). The median number of IM-SLN and IM-nSLN was 2 (1~4) and 3 (1~9), respectively. The positive rate of IMLN and IM-SLN was 37.8% (70/185) and 36.8% (68/185), respectively, yielding the false negative rate of IM-SLNB 2.9% (2/70), the accuracy of 98.9% (183/185) and the sensitivity of 97.1% (68/70). The false negative rate of patients with cN+ disease and patients with positive axillary SLN was 4.8% (2/42) and 0, respectively. The positive IM-SLNs were the only positive IMLNs identified in 51.4% (36/70) patients. IM-SLNB can change the pN stages of 37.2% (68/183) patients. IMLN irradiation could be avoided in 72.7% (80/110) patients with axillary pN1 and 46.7% (35/75) with pN2/N3 disease in the study. Conclusions: The modified technique of radiotracer injection (periareolar intraparenchymal, high volume, and ultrasound guidance) can significantly improve the detection rate of IM-SLN with very low false-negative rate with the prospective, multicenter validation results, providing minimally invasive staging and guiding individual IMLN radiation. When there is no IM-SLN visualization, the nomogram can predict the risk of IMLN metastasis and guide IMLN radiation. The nomogram which can predict the risk of IMLN metastasis The nomogram which can predict the risk of IMLN metastasis Citation Format: Yong-Sheng Wang, Qing Lu, Shi-Guang Zhu, Wen-He Zhao, Guang-Lun Yang, Yuan-Xi Huang, Hong Zhong, Xiao Sun, Pengfei Qiu. Prospective, multicenter, clinical validation study of the repeatability and accuracy of internal mammary sentinel lymph node biopsy with modified injection technique (CBCSG026/CBCSG027) [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P2-14-06.

Background: T-cell immunoglobulin and mucin-domain containing molecule-3 (Tim-3) has been recognized as a promising target for cancer immunotherapy, but its exact role in breast cancer has not been fully elucidated. Methods: The gene expression level of Tim-3 in breast cancer and its prognostic significance were analysed. In vitro functions and associated mechanisms were then explored through establishing Tim-3 overexpressing breast cancer cells.Results: The gene expression level of Tim-3 was significantly higher (p<0.001) in breast cancer tissue compared to normal tissue following pooled analysis of TCGA database. Tim-3 was a prognosis indicator in breast cancer patients as shown by KM-plotter (RFS: p=0.004; OS: p=0.099). Overexpression of the Tim-3 in Tim-3low breast cancer cells promoted aggressiveness of breast cancer cells including proliferation, migration, invasion, tight junction deterioration and tumour-associated tubal formation. Furthermore, Tim-3 enhanced cellular resistance to paclitaxel. Tim-3 exerted its function by activating the NF-κB/STAT3 signalling pathway, and mediating gene regulation (upregulating CCND1, C-Myc, MMP1, TWIST, VEGF while downregulating E-cadherin). Additionally, Tim-3 downregulated tight junction molecules: ZO-2, ZO-1 and Occludin, which might further facilitate the tumour progression. Conclusions: Tim-3 plays a tumour-promoting role in breast cancer, which suggests targeting Tim-3 may acquire a clinical benefit in antitumor therapy.