Rare thoracic cancers: a comprehensive overview of diagnosis and management of small cell lung cancer, malignant pleural mesothelioma and thymic epithelial tumours

Pleural small cell lung cancer masquerading as malignant mesothelioma: A case report

Nodular soft tissue pleural thickening on imaging is highly suggestive of malignancy, of which pleural malignant mesothelioma and metastatic disease are differentials. We present the case of a 71-year-old male who presented with acute worsening of shortness of breath associated with a recurrent left pleural effusion post-pleurocentesis. He was an ex-smoker with previous asbestos exposure. Computed tomography performed demonstrated left-sided pleural thickening in the hemithorax and hemidiaphragm with complex pleural effusion. 18F-2-deoxy-d-glucose whole body PET scan revealed extensive uptake throughout the left hemithorax in multiple pleural masses. The imaging findings and clinical case were typical of malignant mesothelioma. However, histopathology results revealed small cell lung cancer. We need to be cognisant of this atypical presentation of a common disease entity. Even when all clinical and imaging findings point towards a certain diagnosis, histopathological assessment cannot be ignored.

ETV6-NTRK2 Fusion in a Patient With Metastatic Pulmonary Atypical Carcinoid Successfully Treated With Entrectinib: A Case Report and Review of the Literature

Pulmonary atypical carcinoid (AC) is an extremely rare neuroendocrine tumor. The neurotrophic tropomyosin receptor kinase (NTRK) fusions are reported in only 0.5% of nonsmall cell lung cancer, and are more rare in AC with only one previously reported case. Currently, there is little established evidence on the optimal therapeutic strategies and prognosis for advanced cases. We present a female patient with metastatic AC after complete resection. Due to low expression of somatostatin receptor in this case, somatostatin analogs and peptide receptor radionuclide therapy were not available. After pursuing other alternative treatments, including chemotherapy (ie, carboplatin, etoposide, capecitabine, temozolomide, and paclitaxel), everolimus, and atezolizumab, she returned with significant progression, including innumerable subcutaneous nodules, left pleura metastasis, multiple bone metastases, and brain metastases. New biopsy analysis revealed an ETV6-NTRK2 fusion. She was immediately administered the first-generation tropomyosin receptor kinase inhibitor entrectinib at a dose of 600 mg q.d. A subsequent month of treatment resulted in a complete response in all of the metastatic lung lesions. To date, she has maintained sustained benefit for at least 1 year from initiation of entrectinib. Here, we present the first case of a female patient with metastatic AC harboring the ETV6-NTRK2 fusion, and successfully treated with entrectinib, providing evidence for the application of entrectinib in patients with NTRK-positive AC, and underscoring the critical role of molecular profiling for such cases.

EORTC-SPECTA Arcagen study, comprehensive genomic profiling and treatment adaptation of rare thoracic cancers

Arcagen (NCT02834884) is a European prospective study aiming at defining the molecular landscape of rare cancers for treatment guidance. We present data from the cohort of rare thoracic tumors. Patients with advanced pleural mesothelioma (PM) or thymic epithelial tumors (TET) underwent genomic profiling with large targeted assay [>300 genes, tumor mutational burden (TMB), microsatellite instability (MSI) status] on formalin-fixed paraffin-embedded (FFPE) or plasma samples. EORTC molecular tumor board (MTB) advised for biomarker-guided treatments. 102 patients recruited from 8 countries between July 2019 and May 2022 were evaluable: 56 with PM, 46 with TET (23 thymomas, 23 thymic carcinomas). Molecular profiling was performed on 70 FFPE samples (42 PM, 28 TET), and 32 cases on ctDNA (14 PM, 18 TET), within a median turnaround time of 8 days from sample reception. We detected relevant molecular alterations in 66 out of 102 patients (65%; 79% PM, 48% TET), 51 of 70 FFPE samples (73%; 90% PM, 46% TET), and 15 of 32 plasma samples (47%; 43% PM, 50% TET). The most frequently altered genes were CDKN2A/B, BAP1, MTAP in PM and TP53, CDKN2A/B, SETD2 in TET. The TMB was low (mean 3.2 Muts/MB), 2 PM had MSI-high status. MTB advised molecular-guided treatment options in 32 situations, for 17 PM and 15 TET patients (75% clinical trial option, 22% off-label drug or compassionate use, 3% early access program). Molecular testing and MTB discussion were feasible for patients with rare thoracic cancers and allowed the broadening of treatment options for 30% of the cases.

Malignant mesothelioma tumours: molecular pathogenesis, diagnosis, and therapies accompanying clinical studies

The pathetic malignant mesothelioma (MM) is a extremely uncommon and confrontational tumor that evolves in the mesothelium layer of the pleural cavities (inner lining- visceral pleura and outer lining- parietal pleura), peritoneum, pericardium, and tunica vaginalis and is highly resistant to standard treatments. In mesothelioma, the predominant pattern of lesions is a loss of genes that limit tumour growth. Despite the worldwide ban on the manufacture and supply of asbestos, the prevalence of mesothelioma continues to increase. Mesothelioma presents and behaves in a variety of ways, making diagnosis challenging. Most treatments available today for MM are ineffective, and the median life expectancy is between 10 and 12 months. However, in recent years, considerable progress has already been made in understanding the genetics and molecular pathophysiology of mesothelioma by addressing hippo signaling pathway. The development and progression of MM are related to many important genetic alterations. This is related to NF2 and/or LATS2 mutations that activate the transcriptional coactivator YAP. The X-rays, CT scans, MRIs, and PET scans are used to diagnose the MM. The MM are treated with surgery, chemotherapy, first-line combination chemotherapy, second-line treatment, radiation therapy, adoptive T-cell treatment, targeted therapy, and cancer vaccines. Recent clinical trials investigating the function of surgery have led to the development of innovative approaches to the treatment of associated pleural effusions as well as the introduction of targeted medications. An interdisciplinary collaborative approach is needed for the effective care of persons who have mesothelioma because of the rising intricacy of mesothelioma treatment. This article highlights the key findings in the molecular pathogenesis of mesothelioma, diagnosis with special emphasis on the management of mesothelioma.

The flare of care for rare: per aspera ad astra for rare lung diseases!

Rare lung diseases have been noticed for centuries: studies on a mummy of an Egyptian male from the 12th dynasty (1991–1783 BC) showed the presence of an interstitial lung disease called sand pneumoconiosis [1]. Rare disorders have a great impact on patients and their families, yet they are frequently misdiagnosed and undertreated [2]. This is caused, in part, by general as well as healthcare professionals’ lack of knowledge of these disorders. Additionally, because rare disorders are so uncommon, there is frequently a shortage of funding for studies into, and management of, these conditions. The understanding and treatment of rare diseases did not make substantial strides until the end of the 20th century. In 1997, the European Organization for Rare Diseases (EURORDIS) was established to advocate on behalf of patients with rare diseases and their families at the European level [3]. With the adoption of the Orphan Medicinal Products Regulation (following the United States’ Orphan Drug Act), a system of incentives for the development of orphan medications was established in the European Union (EU) in 2000.

For rare lung diseases cross border collaborations and joining forces, such as between ERN-LUNG and ERS as well as patient organisations, are crucial to improve diagnosis and management of these diseases.https://bit.ly/3HpqGX1