Triple-negative breast cancer (TNBC) cells are in a more hypoxic and starved state than non-TNBC cells, which makes TNBC cells always maintain high autophagy levels. Emerging evidence has demonstrated that circular RNAs (circRNAs) are involved in the progress of tumorigenesis. However, the regulation and functions of autophagy-induced circRNAs in TNBC remain unclear. In our study, autophagy-responsive circRNA candidates in TNBC cells under amino acid starved were identified by RNA sequencing. The results showed that circEGFR expression was significantly upregulated in autophagic cells. Knockdown of circEGFR inhibited autophagy in TNBC cells, and circEGFR derived from exosomes induced autophagy in recipient cells in the tumor microenvironment. In vitro and in vivo functional assays identified circEGFR as an oncogenic circRNA in TNBC. Clinically, circEGFR was significantly upregulated in TNBC and was positively associated with lymph node metastasis. CircEGFR in plasma-derived exosomes was upregulated in breast cancer patients compared with healthy people. Mechanistically, circEGFR facilitated the translocation of Annexin A2 (ANXA2) toward the plasma membrane in TNBC cells, which led to the release of Transcription Factor EB (a transcription factor of autophagy-related proteins, TFEB) from ANXA2-TFEB complex, causing nuclear translocation of TFEB, thereby promoting autophagy in TNBC cells. Meanwhile, circEGFR acted as ceRNA by directly binding to miR-224-5p and inhibited the expression of miR-224-5p, which weakened the suppressive role of miR-224-5p/ATG13/ULK1 axis on autophagy. Overall, our study demonstrates the key role of circEGFR in autophagy, malignant progression, and metastasis of TNBC. These indicate circEGFR is a potential diagnosis biomarker and therapeutic target for TNBC.

Background: Triple‐negative breast cancer (TNBC) is the most aggressive type of breast cancer. Immune checkpoint inhibitors (ICIs) have been widely used to treat various tumors and have changed the landscape of tumor management, but the data from real‐world studies of ICIs for TNBC treatment remain limited. The aim of this study was to evaluate the efficacy of ICIs in the treatment of patients with advanced TNBC in a real‐world setting and to explore possible correlates.Methods: The clinical data of advanced TNBC patients who received ICI treatment in the Chinese People's Liberation Army (PLA) General Hospital were collected. Treatment responses, outcomes and adverse events (AEs) were assessed.Results: Eighty‐one patients were included in the study. The confirmed objective response rate (ORR) was 32.1%, and the disease control rate (DCR) was 64.2%. The median progression‐free survival (PFS) was 4.2 months, and the median overall survival (OS) was 11.0 months. PFS and OS were longer in patients who achieved clinical benefit from ICIs and shorter in patients who received later‐line ICIs and higher levels of inflammation; specifically, patients with higher TILs had longer PFS. Overall AEs were tolerable.Conclusions: ICIs are effective in the treatment of advanced TNBC, and the adverse reactions are tolerable. A panel of biomarkers including LDH, ALP, and bNLR were identified to predict the efficacies of ICIs in TNBC treatment.

Background: Everolimus is beneficial for patients with hormone receptor-positive and human epidermal growth factor receptor 2-negative (HR+/HER2−) advanced breast cancer (ABC). However, some patients developed drug resistance and the well-established predictor for everolimus efficacy was limited.Objectives: The study was designed to evaluate the efficacy of everolimus in different treatment lines and identify several clinicopathological markers to estimate everolimus efficacy in patients with HR+/HER2− ABC.Design: This was a retrospective and multicenter study.Methods: Between 2014 and 2022, more than 2000 patients with tumors who received everolimus were collected from multiple cancer centers in China (National Cancer Center, Chinese PLA General Hospital, Peking University Cancer Hospital & Institute). A training cohort and two validation cohorts were developed.Results: The training cohort included 338 patients. The median progression-free survival (PFS) for everolimus was 5.6 months, with an objective response rate of 25.1% and a clinical benefit rate of 54.4%. PFS was significantly worse from first-line (1L) to second-line (2L) to third-line (3L), with PFS_1Lfor 13.5 months, PFS_2Lfor 6.1 months, and PFS_3Lfor 4.1 months ( p = 2.9e−6, hazard ratio (HR) = 0.70, 95% confidence interval (CI) = 0.61–0.82). The clinicopathological characteristics, including post-1L everolimus treatment, Ki67 index of more than 40%, more than two metastatic sites at first recurrence, and receiving adjuvant chemotherapy, were independent risk factors for PFS. A predictive model for everolimus efficacy was established using these four factors. In the low-risk group, patients achieved a median PFS of 12.6 months, significantly longer compared to 2.7 months for those in the high-risk group ( p = 2.4e−64, HR = 9.41, 95% CI = 7.05–12.56). The area under the curve was 0.96, 0.95, and 0.94 for 6-month, 1-year, and 3-year PFS, respectively. Internal validation cohort (PFS 18.4 vs 3.1 months, p = 3.6e−11, HR = 3.78, 95% CI = 2.49–5.74) and external validation cohort (PFS 13.5 vs 3.1 months, p = 2.9e−10, HR = 11.53, 95% CI = 4.68–28.37) confirmed its power for estimating clinical benefits of everolimus.Conclusion: A predictive model was successfully established to predict survival outcomes for everolimus in patients with HR+/HER2− ABC, which may provide references for the management of everolimus in Chinese patients with HR+/HER2− ABC.

Cyclin-dependent kinase 4/6 inhibitor (CDK4/6i) and everolimus (EVE) are effective for patients with hormone receptor–positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer (MBC). However, the efficacy of different sequences of CDK4/6i and EVE are largely unknown. The study aimed to explore the efficacy of different sequences in China. 146 patients with HR+/HER2- MBC who received both CDK4/6i and EVE in salvage setting were collected. Objective response rate (ORR), clinical benefit rate (CBR), progression-free survival (PFS), and overall survival (OS) were investigated. 56 patients received CDK4/6i prior to EVE (Group A), 90 patients received CDK4/6i subsequent to EVE (Group B). The median PFS of CDK4/6i and EVE in Group A vs Group B were 8.4m and 2.5m vs 4.6m and 6.1m respectively. The total PFS of first-line and second-line endocrine therapy were not different between Group A and Group B [13.1m vs 17.7m (P = 0.330, HR = 0.738, 95%CI: 0.399–1.365)]. The 5y OS of patients in Group A or Group B were 62.0 % vs 57.4 %, P = 0.569. We found that no matter CDK4/6i or EVE was used first, the survival were not significantly different between Group A and Group B. Both can be clinical options.