Case Report: PTEN Mutation Induced by anti-PD-1 Therapy in Stage IV Lung Adenocarcinoma

Lung cancer is the most common solid tumor in the worldwide. Targeted therapy and immunotherapy are important treatment options in advanced non-small cell lung cancer (NSCLC). The association of PTEN mutation and tumor immunotherapy is less established for patients with NSCLC. We present the case of an Asian woman diagnosed with stage IV lung adenocarcinoma harboring an ERBB2 mutation. She received Nivolumab treatment when her disease progresses after previous chemotherapy and Afatinib treatment. However, the patient did not response to Nivolumab. PTEN mutation was detected by next-generation sequencing (NGS) after treatment with Nivolumab. PTEN, a secondary mutation, may be served as a biomarker of resistance to anti-PD-1 immunotherapy in lung adenocarcinoma. The relationship between PTEN mutation and immunotherapy is complex and needs further study.

Clinicopathological Features, Tumor Mutational Burden, and Tumour-Infiltrating Lymphocyte Interplay in ERBB2-Mutated Breast Cancer: In Silico Analysis

Recent evidence suggests that somatic mutations in ERBB2 activate ERBB2 signaling. These mutations occur at a frequency of approximately 3% in breast cancer (BC). ERBB2 mutations indicate poor prognosis as they are associated with recurrence and metastasis. This study aimed to evaluate the clinicopathological features, immune infiltration levels, tumor mutational burden (TMB), and tumor-infiltrating lymphocytes (TILs) in ERBB2-mutated breast cancer (ERBB2-mutated BC) using a bioinformatic approach and publicly available datasets (i.e., TCGA-BRCA and TIMER2.0). ERBB2-mutated BCs were associated with a high histological grade. ERBB2-mutated BCs comprised invasive breast carcinoma of no special type (21/35, 60%), classic invasive lobular carcinoma (12/35, 34.3%), and pleomorphic invasive lobular carcinoma (2/35, 5.7%). A Kaplan-Meier survival curve demonstrated that ERBB2-mutated BC was associated with a significantly worse prognosis compared to ERBB2 non-mutated BC (p < 0.01). Furthermore, 40% (14/35) of the patients with ERBB2-mutated BC harbored CDH1 mutations. Mutations at L755 and V777 accounted for 30.5% of these mutations in ERBB2-mutated BC, suggesting that these sites are mutational hot spots in BC, particularly in invasive lobular carcinoma. Of the ERBB2-mutated BCs, 8.6% were classified as TIL-high, whereas 77.1% were TILs-low; TMB significantly correlated with TILs (p < 0.05). CD8⁺ T cell infiltration levels were significantly higher in ERBB2 non-mutated BC. Among ERBB2-mutated BCs, 22.9% were classified as TMB-high, which was significantly higher than the rate in the ERBB2 non-mutated BC (p < 0.01). These findings provide evidence for a link between ERBB2 mutations and high TMB in BC.