Introduction:
Optimal radiotherapy utilisation (RTU) modelling estimates the proportion of people with cancer who would benefit from radiotherapy. Older adults with cancer may have comorbidities which impact on physiological reserve and affect radiotherapy recommendations. Assessment of medical comorbidities is an important component for the assessment of treatment suitability. These have not been considered in previous RTU models.
Aim:
We aimed to develop an age- and comorbidity- adjusted optimal RTU model for patients with non-small cell lung cancer (NSCLC) and small-cell lung cancer (SCLC).
Methods:
New South Wales Cancer Registry data (2010-2014) for patients diagnosed with NSCLC and SCLC was linked to radiotherapy data (2010-2015) and hospitalisation data (2008-2015). The Cancer Specific ‘C3 all sites’ comorbidity index was derived from hospital records for each patient. The index cut-off for treatment eligibility was ≥3. This data was then incorporated into an established lung cancer decision tree model to calculate the optimal age and comorbidity RTU. The actual RTU was calculated using the linked datasets. Four age groups were examined: <60, 60-69, 70-79 and 80+ years, with particular focus on patients aged 80+ years.
Results:
14696 patients were diagnosed with NSCLC and 1839 patients were diagnosed with SCLC.
The age- and comorbidity- adjusted optimal RTU decreased with increasing age for both patient groups.
For patients with NSCLC, the optimal comorbidity adjusted- RTU for patients aged 80+ was 49%. The actual RTU for patients aged 80+ years was 25%.
For patients with SCLC, the optimal comorbidity adjusted- RTU for patients aged 80+ was 49%. The actual RTU for patients aged 80+ years was 32%.
Conclusions:
For patients with NSCLC and SCLC, the actual RTU was less than the optimal RTU. This gap requires further research.