BACKGROUND: Cachexia worsens prognosis, quality of life and chemotherapy treatment compliance of patients with lung cancer. Chemotherapy-induced cachexia has also been implicated in lowered mortality. This study aimed to evaluate the frequency of cachexia-related measures and symptoms as outcomes in lung cancer chemotherapy trial protocols and to examine how key trial characteristics influence them. METHOD: We conducted a cross-sectional data analysis of randomised controlled chemotherapy trials of lung cancer registered in four public trial registries between 2012 and 2023. Trial outcome measures included overall survival, treatment toxicity/side effects and cachexia-related indicators such as physical activity, weight/body mass index (BMI), dietary limitations, caloric intake and lean muscle mass. Symptom-related outcomes, including appetite loss, diarrhoea, pain, fatigue/insomnia, constipation, nausea, vomiting, dysphagia, dyspnoea and oral mucositis, were also extracted. Additionally, the number and type of performance status and assessment tool were recorded. Data were summarised descriptively. Chi-square tests were used to examine associations between trial outcomes and characteristics including cancer type, trial location, lead investigator/funding source, assessment tools and trial commencement year. A < 0.05 was considered statistically significance. RESULTS: Of the 335 trial protocols (non-small cell (87.2%) and small cell (12.8%)), most were from Europe (50.4%). The trial lead investigator was from industry (56.7%) followed by academia (25.1%). Allied health professional involvement was minimal (0.6%). Trial protocols mostly recorded overall survival (96.4%) and toxicity (83.9%). However, physical activity, weight/BMI, dysphagia, dyspnoea and oral mucositis were recorded in <30%, with dietary limitations, caloric intake and lean muscle mass recorded in <3% of the trials. Measures and symptoms were not associated with cancer type. Trial location was associated with the measures toxicity, physical activity and caloric intake and all symptoms. Lead investigator was associated with the measures toxicity and weight/BMI and all symptoms except for dyspnoea. Performance status and assessment tools were mentioned in 93.4% and 41.8% of the trials, respectively, with significant associations between assessment tools and outcomes, except for weight/BMI, dietary limitations, lean muscle mass, dysphagia and oral mucositis. There was a significant trend with trial commencement year for the measures physical activity ( = 0.002) and weight/BMI ( = 0.000) and all symptoms, except for appetite loss ( = 0.115) and pain ( = 0.433). CONCLUSIONS: While the reporting of measures and outcomes was generally higher compared to gastrointestinal chemotherapy cancer trials, it still faced significant under-reporting. Assessment tools should include cachexia-specific symptoms to accurately assess the quality of life in patients with lung cancer undergoing chemotherapy clinical trials.