Rare discrepancies in a driver gene alteration within histologically heterogeneous primary lung cancers

Spatial transcriptomics delineates molecular features and cellular plasticity in lung adenocarcinoma progression

Indolent (lepidic) and aggressive (micropapillary, solid, and poorly differentiated acinar) histologic subtypes often coexist within a tumor tissue of lung adenocarcinoma (LUAD), but the molecular features associated with different subtypes and their transitions remain elusive. Here, we combine spatial transcriptomics and multiplex immunohistochemistry to elucidate molecular characteristics and cellular plasticity of distinct histologic subtypes of LUAD. We delineate transcriptional reprogramming and dynamic cell signaling that determine subtype progression, especially hypoxia-induced regulatory network. Different histologic subtypes exhibit heterogeneity in dedifferentiation states. Additionally, our results show that macrophages are the most abundant cell type in LUAD, and identify different tumor-associated macrophage subpopulations that are unique to each histologic subtype, which might contribute to an immunosuppressive microenvironment. Our results provide a systematic landscape of molecular profiles that drive LUAD subtype progression, and demonstrate potentially novel therapeutic strategies and targets for invasive lung adenocarcinoma.

Novel MRPS9-ALK Fusion Mutation in a Lung Adenocarcinoma Patient: A Case Report

Anaplastic lymphoma kinase (ALK) rearrangements account for approximately 5-6% of non-small-cell lung cancer (NSCLC) patients. In this study, a case of lung adenocarcinoma harboring a novel MRPS9-ALK fusion is reported. The patient responded well to the first and second generation of ALK-tyrosine kinase inhibitors (ALK-TKIs) (crizotinib then alectinib), as her imaging findings and clinical symptoms significantly improved. At last follow-up, over 21 months of overall survival (OS) has been achieved since ALK-TKI treatment. The progression-free survival (PFS) is already ten months since alectinib. The adverse effects were manageable. The case presented here provides first clinical evidence of the efficacy of ALK-TKIs in NSCLC patients with MRPS9-ALK fusion.

Applicability of the adjusted graded prognostic assessment for lung cancer with brain metastases using molecular markers (Lung-molGPA) in a Chinese cohort: A retrospective study of multiple institutions

Background

In this era of precision medicine, prognostic heterogeneity is an important feature of patients with non‐small cell lung cancer (NSCLC) with brain metastases (BM). This multi‐institutional study is aimed to verify the applicability of the adjusted Lung‐molGPA model for NSCLC with BM in a Chinese cohort.

Methods

This retrospective study included 1903 patients at three hospitals in Southwest China. The performance of the Lung‐molGPA model was compared with that of the adjusted DS‐GPA model in terms of estimating the survival of NSCLC with BM.

Results

The median OS of this patient cohort was 27.0 months, and the adenocarcinoma survived longer than the non‐adenocarcinoma (28.0 months vs 18.7 months, p < 0.001). The adjusted Lung‐molGPA model was more accurate in predicting survival of adenocarcinoma patients than the adjusted DS‐GPA model (C‐index: 0.615 vs 0.571), and it was not suitable for predicting survival of non‐adenocarcinoma patients (p = 0.286, 1.5‐2.0 vs 2.5‐3.0; p = 0.410, 2.5‐3.0 vs 3.5‐4.0).

Conclusions

The adjusted Lung‐molGPA model is better than the DS‐GPA model in predicting the prognosis of adenocarcinoma patients. However, it failed to estimate the prognosis for non‐adenocarcinoma patients.

Clonally-related primary ALK rearranged adenocarcinoma and associated metastatic lesions

ALK rearrangement is a driver gene in non‐small cell lung cancer (NSCLC). ALK‐positive tumors are sensitive to ALK‐tyrosine kinase inhibitors (TKIs). The detection of key driver genes is crucial to enable personalized treatment. Different histomorphological patterns have different driver genes. Herein, we report the case of a 42‐year‐old male patient diagnosed with adenocarcinoma with different histomorphologies in the primary lung site (mucinous type) and lymph node metastasis (solid type), of the same genotype, both presenting with ALK rearrangement but negative for EGFR mutation. This histological heterogeneity did not necessarily indicate a genomic difference. Genomic analysis may be a supplement to the histological features of ALK‐rearranged tumors. These gene alterations could aid the choice of an appropriate TKI and predict therapeutic response.

Mixed Responses to Systemic Therapy Revealed Potential Genetic Heterogeneity and Poor Survival in Patients with Non-Small Cell Lung Cancer

BACKGROUND

A subset of patients with non-small cell lung cancer (NSCLC) fosters mixed responses (MRs) to epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) or chemotherapy. However, little is known about the clinical and molecular features or the prognostic significance and potential mechanisms.

METHODS

The records of 246 consecutive patients with NSCLC receiving single-line chemotherapy or TKI treatment and who were assessed by baseline and interim positron emission tomography/computed tomography scans were collected retrospectively. The clinicopathological correlations of the MR were analyzed, and a multivariate analysis was performed to explore the prognostic significance of MR.

RESULTS

The overall incidence of MR to systemic therapy was 21.5% (53/246) and predominated in patients with stage IIIB-IV, EGFR mutations and those who received TKI therapy (p < .05). Subgroup analyses based on MR classification (efficacious versus inefficacious) showed significant differences in subsequent treatment between the two groups (p < .001) and preferable progression-free survival (PFS) and overall survival (OS) in the efficacious MR group. Multivariate analyses demonstrated that the presence of MR was an independent unfavorable prognostic factor for PFS (hazard ratio [HR], 1.474; 95% confidence interval [CI], 1.018-2.134; p = .040) and OS (HR, 1.849; 95% CI, 1.190-2.871; p = .006) in patients with NSCLC. Induced by former systemic therapy, there were more T790M (18%), concomitant EGFR mutations (15%), and changes to EGFR wild type (19%) in the MR group among patients with EGFR mutations, which indicated higher incidence of genetic heterogeneity.

CONCLUSION

MR was not a rare event in patients with NSCLC and tended to occur in those with advanced lung adenocarcinoma treated with a TKI. MR may result from genetic heterogeneity and is an unfavorable prognostic factor for survival. Further studies are imperative to explore subsequent treatment strategies. The Oncologist 2017;22:61-69Implications for Practice: Tumor heterogeneity tends to produce mixed responses (MR) to systemic therapy, including TKI and chemotherapy; however, the clinical significance and potential mechanisms are not fully understood, and the subsequent treatment after MR is also a clinical concern. The present study systemically assessed patients by PET/CT and differentiated MR and therapies. The study identified a relatively high incidence of MR in patients with advanced NSCLC, particularly those treated with targeted therapies. An MR may be an unfavorable prognostic factor and originate from genetic heterogeneity. Further studies are imperative to explore subsequent treatment strategies.