As an aggressive subtype of breast cancer, triple-negative breast cancer (TNBC) is associated with poor prognosis and lack of effective therapy, except chemotherapy. In recent years, immunotherapy based on immune checkpoint (IC) inhibition has emerged as a promising therapeutic strategy in TNBC. TNBC has more tumor-infiltrating lymphocytes (TILs) and higher rate of mutation and programmed cell death ligand-1 (PD-L1) expression than other subtypes of breast cancer have. However, previous studies have shown that monotherapy has little efficacy and only some TNBC patients can benefit from immunotherapy. Therefore, it is important to identify biomarkers that can predict the efficacy of IC inhibitors (ICIs) in TNBC. Recently, various biomarkers have been extensively explored, such as PD-L1, TILs and tumor mutational burden (TMB). Clinical trials have shown that PD-L1-positive patients with advanced TNBC benefit from ICIs plus chemotherapy. However, in patients with early TNBC receiving neoadjuvant therapy, PD-L1 cannot predict the efficacy of ICIs. These inconsistent conclusions suggest that PD-L1 is the best to date but an imperfect predictive biomarker for efficacy of ICIs. Other studies have shown that advanced TNBC patients with TMB ≥10 mutations/Mb can achieve clinical benefits from pembrolizumab. TILs also have potential predictive value in TNBC. Here, we select some biomarkers related to ICIs and discuss their potential predictive and prognostic value in TNBC. We hope these biomarkers could help to identify suitable patients and realize precision immunotherapy.

Background Pyrotinib, a novel irreversible epidermal growth factor receptor 2 (EGFR)/HER2 dual tyrosine kinase inhibitor, has shown promising antitumor efficacy with tolerable toxicity in HER2‐positive metastatic breast cancer (MBC) in several clinical trials. However, the clinical trials do not usually well reflect the patients in real clinical settings. Despite several small‐sample studies in real world, the data on pyrotinib as first‐line and third‐or‐later‐line treatment and the efficacy comparison of pyrotinib combined with different regimens are still lacking. Therefore, this study aimed to investigate the efficacy and safety of pyrotinib for the HER2‐positive MBC in real world to replenish more comprehensive data. Methods A total of 172 HER2‐positive MBC patients treated with pyrotinib‐based therapy were recruited from multiple centers in nonclinical trial settings from September 2017 to June 2020. Results The median progression‐free survival (mPFS) of 172 patients was 8.83 months. The patients, receiving first‐line pyrotinib treatment, had the longest mPFS (20.93 months) compared with those receiving second‐line (8.67 months, p = 0.0339) and third‐or‐later‐line (7.13 months, p = 0.0075) treatments, respectively. Prior treatment with lapatinib ( p = 0.012) and site of metastasis (visceral vs. nonvisceral) ( p = 0.033) were the independent prognostic factors for PFS. The prior treatment with lapatinib compared with lapatinib‐native treatment (5.96 vs. 10.97 months, p = 0.0036) and those with visceral metastasis compared with nonvisceral metastasis (8.40 vs. 23.70 months, p = 0.0138) had worse mPFS. Among 146 patients evaluated for efficacy, 2.1%, 58.9%, and 32.9% showed complete response, partial response, and stable disease, respectively. Adverse events occurred in 92.4% of the patients with 33.3% Grade 3 and higher adverse events and diarrhea (57.0%), anemia (44.8%), and leukopenia (40.7%) as the most frequent ones. Conclusions Pyrotinib‐containing regimen could effectively treat HER2‐positive MBC with acceptable toxicity, including the patients who progressed after lapatinib treatment and with brain metastasis.

Background: Occult breast cancer (OBC) is a rare type of breast cancer, which accounts for 0.3-1.0% of all breast cancers. However, the treatment of OBC remains controversial, especially the local treatment. We aimed to analyze the impact of different treatment and N stage on survival in early-stage OBC patients, and construct a nomogram to predict the prognosis. Methods:The data of patients with early-stage breast cancer were obtained from 17 registries in the Surveillance, Epidemiology, and End Results (SEER) database. Patient characteristics and breast cancerspecific survival (BCSS) were compared among the groups. Cox proportional risk models were used for both the univariate and multivariate analyses. Variables with a P value <0.07 in the univariate analysis were included in the multivariate analysis. The independent prognostic factors were included in the nomogram and validated internally.Results: A total of 492 early-stage OBC patients were randomized at a 7:3 ratio into the training cohort (n=348) and the testing cohort (n=144). N2+ stage patients had a worse prognosis than N1 stage patients (P=0.0051). Triple-negative breast cancer (TNBC) patients had the worst prognosis. Early-stage OBC patients benefited from surgery (P=0.0093) and radiotherapy (P=0.0102), but not chemotherapy (P=0.4030).An analysis of OBC patients with different N stages showed that in terms of treatment, N1 stage patients benefited from surgery (P=0.023), but did not benefit significantly from radiotherapy (P=0.0793), whereas N2+ stage patients benefited from radiotherapy (P=0.0098), but the benefit from surgery was not significant (P=0.1005). In the multivariate analysis, N stage, surgery, and radiotherapy remained statistically significant.Based on the results of the multivariate analysis, we constructed a nomogram for estimating the 3-and 5-year BCSS of OBC patients. The concordance index and the calibration plots show that our nomogram had sufficient accuracy and good coordination.Conclusions: N stage, surgery, and radiotherapy were identified as independent prognostic factors for OBC. We successfully constructed a nomogram using these independent risk factors and demonstrated that it could help predict the 3-and 5-year BCSS of OBC patients. Further data analyses need to be conducted to revise the treatment of early-stage OBC.