Background

Patients with rare cancers in the Top End of the Northern Territory (NT) face worse survival than other parts of the country (1). This study sought to provide epidemiological context for this disparity, and to identify potential factors affecting survival of rare cancer patients in the Top End.

Methods

Retrospective cohort study of adults residing in the Top End of the NT diagnosed with a rare, invasive solid organ malignancy between 1 January 2016 and 30 December 2020. Patients were identified from the NT Cancer Registry and cross-referenced to hospital records. Patient demographic factors reviewed include age, Indigenous status, remoteness classification, smoking and alcohol history. Quality of treatment was evaluated by examining timeliness of treatment, cultural safety, multidisciplinary meeting discussion, and involvement in clinical trials. Factors associated with overall survival were determined using multivariate analyses.

Results

784 patients were diagnosed with rare solid tumours, comprised of 287 unique subtypes. Hepatocellular carcinoma was the most prevalent diagnosis. Most patients waited more than 28 days from diagnosis to start treatment, and fewer than 5% of patients participated in a clinical trial. Indigenous and remote patients were more likely to be diagnosed with Stage IV disease, to decline treatment, and died sooner. Indigenous and remote status however were not independently associated with worse survival on multivariate analysis, whereas performance status, stage, age and tumour site were each strongly associated with impaired survival.

Conclusions

Rare cancer patients in the Top End face barriers to optimal cancer care with opportunities for improvement in risk factor modification, time from diagnosis to treatment, use of Indigenous support persons, and patient involvement in clinical trials.

References

1) Dasgupta P et al. Geographical and spatial disparities in the incidence and survival of rare cancers in Australia. Int J Cancer. 2023 Apr 15;152(8):1601–12.