Functional Outcomes in Lung Cancer Rehabilitation

Introduction

While lung cancer is the third most common cancer in males and females (behind breast and prostate cancer), it is the leading cause of cancer related death in the United States. ^, The 2-year survival rate ranges from 15% to 42% depending on the type of lung cancer. Risk factors for developing lung cancer include age >50 years, tobacco smoke exposure, and male gender. Smoking cessation can therefore considerably reduce the risk of developing lung cancer along with adequate lung cancer screening for high-risk patients. While small cell lung cancer is associated with cigarette smoking, the most common type of lung cancer is nonsmall cell lung cancer, specifically adenocarcinoma, large cell carcinoma, and squamous cell carcinoma. ^,

Treatment for lung cancer depends on the type and stage of the cancer at the time of diagnosis. Surgical intervention includes tumor resection or lobectomy (removal of the affected lobe). Radiation therapy is utilized for regional spread of the cancer and can be used both curatively and palliatively. Common chemotherapy regimens often include a combination of platinum agents (carboplatin), taxols (docetaxel), and/or antimetabolites (pemetrexed, gemcitabine). While chemotherapy directly targets rapidly dividing cells, newer immune checkpoint inhibitors (ICPIs) such as pembrolizumab work to stimulate an immune response against tumor cells.

With improvements in treatment (especially the addition of ICPIs) and tobacco control efforts, the overall mortality of lung cancer has decreased for both the male and female populations. ^, Patients are therefore living longer and experiencing a plethora of side effects from the cancer itself and its treatments. These side effects include but are not limited to chemotherapy-induced neuropathy (CIN), radiation fibrosis/myopathy/myelopathy, ICPI-induced neuromuscular disorders, fatigue, chronic pain, cognitive dysfunction, and breathing problems. Early targeted and multidisciplinary treatment of conditions can significantly improve a patient's quality of life and overall health and function.

Cancer rehabilitation as a specialty is focused on anticipating and then addressing these oncologic factors through longitudinal monitoring of cancer patients. Depending on the timing and nature of the side effects, cancer rehabilitation efforts can be broken down into preventative, restorative, supportive, and palliative rehabilitation. Preventative rehabilitation (prehabilitation) focuses on early identification of functional deficits in an effort to prevent or delay complications of cancer therapies. Restorative rehabilitation involves comprehensive therapy for cancer patients who have the potential to return to their functional baseline. Supportive rehabilitation is for patients with more severe and potentially permanent deficits in an effort to maintain as much functional independence as possible. Lastly, palliative rehabilitation focuses on maximizing comfort for patients with advanced disease or treatment refractory cancer and support for their families. For all of these rehabilitation efforts, it is essential to establish the functional baseline of lung cancer patients and accurately monitor any changes in functional level before, during, and after cancer treatment.