Study of breast cancer incidence in patients of lymphangioleiomyomatosis

Lung cancer and lymphangioleiomyomatosis: A common complication in an uncommon condition

See related article

Lymphangioleiomyomatosis as a potent lung cancer risk factor: Insights from a Japanese large cohort study

BACKGROUND AND OBJECTIVE

Lymphangioleiomyomatosis (LAM) is a rare neoplastic disease associated with the functional tumour suppressor genes TSC1 and TSC2 and causes structural destruction in the lungs, which could potentially increase the risk of lung cancer. However, this relationship remains unclear because of the rarity of the disease.

METHODS

We investigated the relative risk of developing lung cancer among patients diagnosed with LAM between 2001 and 2022 at a single high-volume centre in Japan, using data from the Japanese Cancer Registry as the reference population. Next-generation sequencing (NGS) was performed in cases where tumour samples were available.

RESULTS

Among 642 patients diagnosed with LAM (sporadic LAM, n = 557; tuberous sclerosis complex-LAM, n = 80; unclassified, n = 5), 13 (2.2%) were diagnosed with lung cancer during a median follow-up period of 5.13 years. All patients were female, 61.5% were never smokers, and the median age at lung cancer diagnosis was 53 years. Eight patients developed lung cancer after LAM diagnosis. The estimated incidence of lung cancer was 301.4 cases per 100,000 person-years, and the standardized incidence ratio was 13.6 (95% confidence interval, 6.2-21.0; p = 0.0008). Actionable genetic alterations were identified in 38.5% of the patients (EGFR: 3, ALK: 1 and ERBB2: 1). No findings suggested loss of TSC gene function in the two patients analysed by NGS.

CONCLUSION

Our study revealed that patients diagnosed with LAM had a significantly increased risk of lung cancer. Further research is warranted to clarify the carcinogenesis of lung cancer in patients with LAM.

Identification of common genetic features and pathways involved in pulmonary lymphangioleiomyomatosis and ER-positive breast cancer

Accumulating evidence suggests that patients with pulmonary lymphangioleiomyomatosis (PLAM) have a markedly higher prevalence of breast cancer (BC) than the general population. However, the underlying pathophysiological mechanisms remain unclear. Therefore, in this study, we employed a bioinformatics approach to understand the association between PLAM and estrogen receptor (ER)-positive BC. The PLAM (GSE12027) and ER-positive BC (GSE42568, GSE29044, and GSE29431) datasets were obtained from the Gene Expression Omnibus database, and GEO2R was used to identify common differentially expressed genes (DEGs) between them. Functional annotation was performed, and a protein-protein interaction (PPI) network was constructed. Hub genes were identified and verified using western blotting and immunohistochemistry. We conducted an immune infiltration analysis; based on the results, selected 102 common DEGs for follow-up analysis. Functional analyses revealed that the DEGs were mostly enriched in cell proliferation, gene expression regulation, and tumor-related pathways. Four hub genes-ESR1, IL6, PLA2G4A, and CAV1-were further analyzed, and CAV1 was revealed to be associated with clinical outcomes and immune infiltration in ER-positive BC. This study proposes a common, possible pathogenesis of PLAM and ER-positive BC. These common pathways and pivotal genes may provide new directions for further mechanistic studies.

Heterogeneity and Cancer-Related Features in Lymphangioleiomyomatosis Cells and Tissue

Lymphangioleiomyomatosis (LAM) is a rare, low-grade metastasizing disease characterized by cystic lung destruction. LAM can exhibit extensive heterogeneity at the molecular, cellular, and tissue levels. However, the molecular similarities and differences among LAM cells and tissue, and their connection to cancer features are not fully understood. By integrating complementary gene and protein LAM signatures, and single-cell and bulk tissue transcriptome profiles, we show sources of disease heterogeneity, and how they correspond to cancer molecular portraits. Subsets of LAM diseased cells differ with respect to gene expression profiles related to hormones, metabolism, proliferation, and stemness. Phenotypic diseased cell differences are identified by evaluating lumican (LUM) proteoglycan and YB1 transcription factor expression in LAM lung lesions. The RUNX1 and IRF1 transcription factors are predicted to regulate LAM cell signatures, and both regulators are expressed in LAM lung lesions, with differences between spindle-like and epithelioid LAM cells. The cancer single-cell transcriptome profiles most similar to those of LAM cells include a breast cancer mesenchymal cell model and lines derived from pleural mesotheliomas. Heterogeneity is also found in LAM lung tissue, where it is mainly determined by immune system factors. Variable expression of the multifunctional innate immunity protein LCN2 is linked to disease heterogeneity. This protein is found to be more abundant in blood plasma from LAM patients than from healthy women. IMPLICATIONS: This study identifies LAM molecular and cellular features, master regulators, cancer similarities, and potential causes of disease heterogeneity.

Evidence for shared genetic risk factors between lymphangioleiomyomatosis and pulmonary function

Introduction

Lymphangioleiomyomatosis (LAM) is a rare low-grade metastasising disease characterised by cystic lung destruction. The genetic basis of LAM remains incompletely determined, and the disease cell-of-origin is uncertain. We analysed the possibility of a shared genetic basis between LAM and cancer, and LAM and pulmonary function.

Methods

The results of genome-wide association studies of LAM, 17 cancer types and spirometry measures (forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), FEV1/FVC ratio and peak expiratory flow (PEF)) were analysed for genetic correlations, shared genetic variants and causality. Genomic and transcriptomic data were examined, and immunodetection assays were performed to evaluate pleiotropic genes.

Results

There were no significant overall genetic correlations between LAM and cancer, but LAM correlated negatively with FVC and PEF, and a trend in the same direction was observed for FEV1. 22 shared genetic variants were uncovered between LAM and pulmonary function, while seven shared variants were identified between LAM and cancer. The LAM-pulmonary function shared genetics identified four pleiotropic genes previously recognised in LAM single-cell transcriptomes: ADAM12, BNC2, NR2F2 and SP5. We had previously associated NR2F2 variants with LAM, and we identified its functional partner NR3C1 as another pleotropic factor. NR3C1 expression was confirmed in LAM lung lesions. Another candidate pleiotropic factor, CNTN2, was found more abundant in plasma of LAM patients than that of healthy women.

Conclusions

This study suggests the existence of a common genetic aetiology between LAM and pulmonary function.

Identification of driver genes and somatic mutations in cell-free DNA of patients with pulmonary lymphangioleiomyomatosis

Next-generation sequencing of cell-free circulating DNA (cfDNA) has emerged as promising technique for identifying minimally invasive genomic profiling of tumor cells recently. However, it remains relatively unknown in LAM disease. In our study, paired cfDNA and genomic DNA (gDNA) in blood samples were obtained from 23 LAM patients and seven healthy controls to explore mutations profiles of targeted 70 cancer-related genes. As results, log2-based allele frequencies of mutations in cfDNA were significantly different from those of gDNA. By comparing the mutual mutations identified both in cfDNA and gDNA, a significant correlation was also observed. After removing mutations in gDNA, distinct somatic mutation profiles of cfDNA were observed in LAM patients. Forty of 70 targeted genes had recurrent mutations, of which ATM, BRCA2 and APC showed the highest frequency. Based on the mutation, correlation network constructed of 40 mutated genes, 11 hub genes bearing intensive interactions were highlighted, including BRCA1, BRCA2, RAD50, RB1, NF1, APC, MLH3, ATM, PDGFRA, PALB2 and BLM. Expression of the hub genes showed significant clusters between LAM patients and controls and that RAD50 and BRCA2 had the strongest associations with subject phenotypes. Myogenesis and estrogen response were confirmed to be positively regulated in LAM patients. Collectively, our study provided a landscape of genomic alterations in LAM and discovered several potential driver genes, that is, BRCA2 and RAD50, which shed a substantial light on the clinical application of key molecular markers and potential therapy targets for precision diagnosis and treatment in the future.

Risk of breast cancer in patients with lymphangioleiomyomatosis

Lymphangioleiomyomatosis (LAM) is a rare metastasizing pulmonary disease that shares some clinical, cellular, and molecular similarities with metastatic breast cancer to lung. LAM cells have been identified circulating in various body fluids of patients and, intriguingly, diverse evidence indicates that these cells may originate from a different organ to the lung. Following on from these observations, we hypothesized the existence of a common risk basis between LAM and breast cancer, and suggested increased risk of breast cancer among LAM patients. Here, by studying two additional LAM cohorts with more detailed epidemiological, life-style, and disease-related data, we show consistent results; a potential excess of estrogen-receptor-positive young breast cancer cases in LAM. This observation further suggests the need of prospective studies to precisely assess the association between both diseases.

A Case of Lymphangioleiomyomatosis (LAM) of the Lung in a Patient with a History of Breast Cancer

Patient: Female, 47

Final Diagnosis: Lymphangioleiomyomatosis

Symptoms: Dyspnea

Medication: —

Clinical Procedure: —

Specialty: Pulmonology