Aim: The aim of the study was to present existing evidence regarding the association between bronchial asthma and lung cancer risk, the impact of lung cancer treatment on asthma control as well as the impact of pre-existing asthma on lung cancer survival.
Methods: A narrative review of all the relevant published literature has been conducted.
Results: Published evidence suggests that patients with bronchial asthma are at a higher risk of developing lung cancer with an estimated odds ratio for squamous and small cell lung carcinoma at 1.69 and 1.71, respectively, within 2 years of asthma diagnosis. Interestingly, regular use of inhaled corticosteroids may protect asthmatics against lung cancer. Chemotherapy may temporarily relieve asthma symptoms. Pneumonitis is a common adverse reaction in asthmatics receiving immunotherapy for lung cancer treatment. Lung radiotherapy in asthma patients predisposes to eosinophilic alveolitis and pneumonia. Asthmatics are considered high-risk candidates for invasive surgical procedures because they carry a high risk of perioperative airway hyper responsiveness. Asthma is associated with a reduced lung cancer survival compared to other pulmonary co-morbidities.
Conclusion: Literature shows that bronchial asthma is associated with increased lung cancer risk and worse survival rates. Chemotherapy may relieve asthma symptoms. However, asthmatics are prone to complications related to lung cancer surgery or radiotherapy treatment. Μore randomised controlled studies are required to strengthen the positive association between bronchial asthma and lung cancer, taking into consideration that there may be confounders that may influence the results. Finally, further studies must be conducted to investigate the impact of immunotherapy and specific radiotherapy modalities on asthma control.