Respiratory organ aging and cancer

Abstract

Lung aging begins in the third decade, initiating a gradual decline in maximal pulmonary function that continues throughout the remainder of life. Lung aging may mimic obstructive and restrictive lung diseases. Lung parenchyma loses elasticity via alveolar wall and mesenchymal degradation and distortion, similar to emphysema. Muscles of respiration become sarcopenic and weaken, while the thorax contorts due to osteoporotic vertebral fractures, all of which manifest as a restrictive lung function pattern. Chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF) and their pathogenesis may be related to accelerated cellular aging. Chronic lung disease impacts cardiopulmonary fitness, which can lead to decreased physical exertion and resultant frailty. Lung cancer incidence also increases with age and is increased in older adults with COPD and IPF. Lung cancer is the leading cancer-related cause of death in the world. Most lung cancer in the USA is attributable to smoking. Globally, indoor air pollution is also a significant risk factor. Approximately 85% of lung cancer is non-small cell lung cancer (NSCLC), and adenocarcinoma is the predominant histologic type. Depending on stage at diagnosis, treatment options can include surgical resection, medical therapy (e.g., chemotherapy, driver mutation-targeted agents, and immunotherapy), and radiation therapy (photon or proton). Best care practices mandate that multidisciplinary teams formulate treatment plans to optimize care. Comprehensive geriatric assessments are useful decision-making tools and may improve survival while limiting treatment toxicity. Surgical resection impacts postoperative lung function, so preoperative evaluations must include pulmonary function testing with additional cardiopulmonary testing as indicated. Early palliative care interventions should be a cornerstone of medical management in advanced lung cancer.