National variation in the treatment of lung cancer in a universal healthcare context.

backgroundLung cancer survival can be improved through treatment, but several factors can influence the pattern of treatment received by a given individual. Using national-data across the lung cancer treatment pathway, here we describe treatment variation according to clinical and sociodemographic factors.

methodsWe used national health data linked to the New Zealand Cancer Registry (NZCR) to describe variation in surgery, radiation therapy and systemic therapy for all lung cancers from 2012-2019 (n = 18,081), stratified by ethnicity, cancer stage, area deprivation, rurality status and comorbidity. Crude and adjusted descriptive analysis were used, including marginally standardised risk estimates from logistic regression.

resultsThe most common treatment was radiation therapy, either in isolation or combined with systemic therapy (combined total: crude 37%, fully-adj. 40%). Systemic therapy was the next most common treatment modality (crude 28%, fully-adj. 33%). Surgery was the least common treatment modality, used in around 15% of the cohort (crude 18%, fully-adj. 15%). Once adjusted for other factors, treatment access varied somewhat by ethnicity. Increasing stage of disease reduced the likelihood of surgery and increased the likelihood of radiation and systemic therapy. Increasing deprivation marginally reduced access to surgery, while rurality appeared to have no independent impact. Increasing comorbidity reduced the overall likelihood of treatment, systemic therapy alone, and radiation therapy + systemic therapy in combination. DISCUSSION: We found variation in the pattern of cancer treatment received according to factors including ethnicity, stage, deprivation and comorbidity, but no clear independent variation by rurality.