Introduction Malignant pleural effusions (MPEs) commonly occur in patients with advanced cancer. Drainage of fluid is used to relieve symptoms and improve quality of life.

Objective To improve our understanding of how therapeutic aspiration affects symptoms and activities in patients with MPE.

Methods Patients presenting to the Pleural Clinic at Norfolk and Norwich University Hospital with a confirmed or suspected MPE participated in up to three semistructured interviews during their diagnostic/therapeutic pathway. Interviews were analysed using framework analysis by two researchers independently.

Results Sixteen patients participated. Symptoms reported before drainage included breathlessness, cough, chest pain, fatigue and anorexia. Symptoms affected their activities, including walking, bending over and socialisation. Patients described anxiety about the underlying diagnosis and fear of over-reliance on others. Expectations of drainage outcome varied, with some hoping for a cure and others hoping for any improvement. After drainage, breathlessness, chest pain and cough improved in some patients. They reported feeling and sleeping better, but fatigue and poor appetite remained. Participants were more active after aspiration, but the duration of improvement was a few days only. Despite this, patients still felt the procedure worthwhile.

Conclusion Overall health and respiratory symptoms improved following drainage, but constitutional symptoms did not improve. This may be because constitutional symptoms are caused by the underlying cancer. This study suggests that clinicians should consider a range of symptoms, rather than just breathlessness, in planning outcomes for clinical trials. These results are important to inform patients about the potential benefits and duration of symptom improvement after therapeutic aspiration.