Traditional Treatment Approaches and Role of Immunotherapy in Lung Malignancy and Mesothelioma

Abstract

There is no denying that many revolutions took place in the fight against cancer during the last decades. However, cancers have always managed to find new ways to challenge humankinds. Variable genomic epidemiology, socio-economic differences and limitations of widespread screening are the major concerns in cancer diagnosis and early treatment. A multidisciplinary approach is essentially to manage a cancer patient efficiently. Thoracic malignancies including lung cancers and pleural mesothelioma are accountable for little more than 11.6% of the global cancer burden [4]. Mesothelioma is one of the rare cancers, but concern is the incidences are increasing globally. However, the good news is first-line chemotherapy with the combination of immune checkpoints inhibitors (ICIs) in non-small cell lung cancer (NSCLC) and mesothelioma has showed promising respond and improved overall survival (OS) in pivotal clinical trials [10]. ICIs are commonly referred as immunotherapy are antigens on the cancer cells, and inhibitors are the antibodies produce by the T cell defence system. By inhibiting immune checkpoints, the cancer cells become visible to be identified as abnormal cells and attack by the body’s defence system [17]. The programmed death receptor-1 (PD-1) and programmed death receptor ligand-1 (PD-L1) inhibitors are commonly used immune checkpoint blockers for anti-cancer treatment. PD-1/PD-L1 are proteins produced by immune cells and mimic by cancer cells that are implicated in inhibiting T cell response to regulate our immune system, which results tumour cells escaping the defence mechanism to achieve immune surveillance. Therefore, inhibiting immune checkpoints as well as monoclonal antibodies can lead to effective apoptosis of tumour cells [17]. Mesothelioma is an industrial disease caused by significant asbestos exposure. It is the cancer of the mesothelial tissue which presents in the lining of the mediastinum of pleura, pericardium and peritoneum, most commonly affected sites are pleura of the lung or chest wall lining [9] as route of asbestos exposure is inhalation. Calretinin is a calcium binding protein, typically over exposed in malignant mesotheliomas and the most useful marker even while initial changes take place [5]. On the other hand, Wilm’s tumour 1 (WT-1) gene expression on the tumour cells can be related to prognosis as it can elicit immune response, thereby inhibit cell apoptosis. A systematic review and meta-analysis study conducted by Qi et al. has suggested that expression of WT-1 in a solid tumour is fatal however, it gives the tumour cell a feature of immune sensitivity which then acts positively towards the treatment with immunotherapy. Clinical significance of WT-1 oncogene in treatment is still hugely debatable and needs further attention [21]. Recently, Japan has reinstated Nivolumab in patients with chemo-refractory mesothelioma. According to NCCN guidelines, the salvage therapies include Pembrolizumab in PD-L1 positive patients and Nivolumab alone or with Ipilimumab in cancers irrespective of PD-L1 expression [9]. The checkpoint blockers have taken over the biomarker-based research and demonstrated impressive treatment options in immune sensitive and asbestos-related cancers. It can be expected that in near future the immune checkpoint inhibitors will be considered as approved first-line cancer treatment universally.