Purpose: To analyze the relationship between titin (TTN) mutation gene and tumor mutational burden (TMB) and the with prognosis of lung squamous cell carcinomas (LUSC), and to explore the feasibility of TTN as a potential prognostic marker of for LUSC. Methods: We analyzed the somatic mutation landscape of LUSC samples using datasets obtained from The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) databases. Sequence data were divided into wild and mutant groups, and differences in TMB values between the groups compared using a Mann–Whitney U-test. The Kaplan Meier method was used to analyze the correlation between TTN mutation and LUSC prognosis, whereas CIBERSORT algorithm was used to calculate the degree of relative enrichment degree of among tumor-infiltrating lymphocytes in LUSC. Results: Analysis of both datasets revealed high mutations in the TTN gene, with mutants exhibiting a significantly higher TMB value relative to the wild-type (P < 0.001). Prognosis of the TTN mutant group in LUSC was significantly better than that of wild-type (P = 0.009). Kaplan Meier curves showed that TTN mutation may be an independent prognostic factor in LUSC patients (HR: 0.64, 95% CI 0.48– 0.85, P = 0.001), while GSEA analysis revealed that TTN mutation plays a potential role in the development of LUSC. Finally, analysis of LUSC immune microenvironment revealed that TTN mutation was significantly associated with enrichment of macrophages M1 (p < 0.05). Conclusion: TTN mutation is associated with TMB, and is positively correlated with prognosis of LUSC. Therefore, this mutation may serve as a potential prognostic indicator of LUSC.

Background: On April 15, 2021, the Surveillance, Epidemiology, and End Results (SEER) database released the latest lung cancer follow-up data. We selected 922,317 lung cancer patients diagnosed from 2000 to 2017 for survival analysis to provide updated data for lung cancer researchers. Research Question: This study explored the latest trends of survival time in terms of gender, race, nationality, age, income, address, histological type and primary site. Study Design and Methods: The SEER database covers 27.8% of the US population. We used life table, Kaplan–Meier, log-rank, Breslow and Tarone-Ware tests to calculate survival rate, time, and curve and to compare differences in survival distribution. We performed univariate and multivariate Cox proportional hazards analyses. Results: The median survival time of all lung cancer patients diagnosed in 2017 increased by 41.72% compared to 2000. Median survival time of female patients diagnosed in 2017 increased by 70.94% compared to 2000. Median survival time of those diagnosed in 2017 for different primary sites was as follows: right middle lobe was the longest, then left lower lobe, right upper lobe, right lower lobe, and left upper lobe. Lung cancer patients older than 75 years had a significantly shorter median survival time. Patients living in metropolitan areas of 250,000 to 1 million had a longer median survival time. Median survival time in the adenocarcinoma group was significantly greater than other patients. Median survival of Asian and other races diagnosed in 2017 was 97.87% higher than those diagnosed in 2000. Survival rate of lung cancer increased gradually with the year of diagnosis. Interpretation: The rapid improvement of the prognosis of female and young lung cancer patients contributes to the improvement of the overall prognosis. Primary lung cancer in the right middle lobe has the best prognosis.

Objective: To construct an in vitro lung cancer model using 3D bioprinting and evaluate the feasibility of the model. Transcriptome sequencing was used to compare the differential genes and functions of 2D and 3D lung cancer cells. Methods: 1. A549 cells were mixed with sodium alginate/gelatine/fibrinogen as 3D-printed biological ink to construct a hydrogel scaffold for the in vitro model of lung cancer; 2. A hydrogel scaffold was printed using a extrusion 3D bioprinter; 3. The printed lung cancer model was evaluated in vitro; and 4. A549 cells cultured in 2D and 3D tumour models in vitro were collected, and RNA-seq conducted bioinformatics analysis. Results: 1. The in vitro lung cancer model printed using 3D-bioprinting technology was a porous microstructure model, suitable for the survival of A549 cells. Compared with the 2D cell-line model, the 3D model is closer to the fundamental human growth environment; 2. There was no significant difference in cell survival rate between the 2D and 3D groups; 3. In the cell proliferation rate measurement, it was found that the cells in the 2D group had a speedy growth rate in the first five days, but after five days, the growth rate slowed down. Cell proliferation showed a declining process after the ninth day of cell culture. However, cells in the 3D group showed a slow growth process at the beginning, and the growth rate reached a peak on the 12th day. Then, the growth rate showed a downward trend; and 4. RNA-seq compared A549 cells from 2D and 3D lung cancer models. A total of 3112 genes were differentially expressed, including 1189 up-regulated and 1923 down-regulated genes, with p-value ≤ 0.05 and |Log2Ratio| ≥ 1 as screening conditions. After functional enrichment analysis of differential genes, these differential genes affect the biological regulation of A549 cells, thus promoting lung cancer progression. Conclusion: This study uses 3D-bioprinting technology to construct a tumour model of lung cancer that can grow sustainably in vitro. Three-dimensional bioprinting may provide a new research platform for studying the lung cancer TME mechanism and anticancer drug screening.

Rationale: With the advancement of targeted therapies, epidermal growth factor receptor tyrosine kinase inhibitors have become the preferred initial treatment for patients with advanced epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer. Osimertinib, a third-generation epidermal growth factor receptor tyrosine kinase inhibitor, is effective against exon 19 and 21 mutations as well as the T790M mutation. It has been approved by both the food and drug administration and European Medicines Agency for the treatment of non-small cell lung cancer patients with locally advanced or metastatic EGFR-mutated tumors, including those who have acquired T790M mutations. Patient concerns: To evaluate the effectiveness of osimertinib in treating patients with EGFR-mutated advanced lung adenocarcinoma and bone metastases, we present the treatment outcomes of 3 patients with EGFR 19 deletion-mutated advanced lung adenocarcinoma and bone metastases who received osimertinib treatment in recent years. All 3 cases involved elderly female patients, aged 62, 62, and 54, respectively. Diagnoses: All 3 cases exhibited a diagnosis of pulmonary adenocarcinoma accompanied by osseous metastases, with genetic testing revealing the presence of an EGFR 19del mutation. Interventions: In the first case, following 17 months of gefitinib therapy, disease progression prompted a switch to osimertinib treatment. In the second case, bone metastases were detected after 20 months of pemetrexed-carboplatin chemotherapy, leading to a transition to osimertinib therapy. In the third case, after 11 months of erlotinib treatment, bone metastases were identified. Subsequent interventions, including radiation therapy, pemetrexed-carboplatin chemotherapy, pemetrexed-bevacizumab maintenance therapy, and docetaxel chemotherapy, failed to arrest the progression of bone metastases. As a result, a combination of osimertinib and anlotinib targeted therapy was administered. Outcomes: All 3 patients experienced relatively good and favorable survival outcomes, with a progression-free survival of 22.7 months, 12 months, and 17.7 months, respectively. Lessons: These cases suggest that osimertinib is a promising treatment option for patients with EGFR 19 deletion-mutated lung adenocarcinoma and bone metastases, although further clinical studies are needed to confirm its efficacy.