Among all patients with neuroendocrine tumours (NETs), the risk of dying of cancer was higher than that of dying of other causes, but mortality varies by primary tumour site, according to a new study published in Journal of the National Comprehensive Cancer Network.

It is the first population-based cohort study to describe factors associated with cancer-specific death after a NET diagnosis.

“Neuroendocrine tumours are very unique in that they are often slow growing indolent cancers. They have very heterogenous behaviours. While some metastatic tumours can threaten patients’ survival, other localised tumours do not. Therefore, it was important to understand cause of death and the exact burden of cancer on mortality in different sub-groups of patients with NETs,” said lead author Julie Hallet, MD, MSc, University of Toronto.

“Our results show that some patients with non-metastatic NETs are more likely to die of other causes than NET. This is crucial to inform patients and make decisions regarding treatment. It is important to make sure that treatment does not present a higher risk than the NET itself. For example, small pancreas, stomach or rectal NETs can be safely monitored.”

The retrospective study of 8,607 patients whose health data were stored at ICES, the not-for-profit research institute in Toronto, Canada, found that the highest risks of cancer-specific death occurred in patients with bronchopulmonary and pancreatic NETs. 

For non-metastatic gastric, small intestine, colonic, and rectal NETs, the risk of non-cancer death exceeded that of cancer-specific deaths. Advancing age, higher material deprivation, and metastases were associated with higher hazard ratios of cancer-specific mortality; while being female and having a higher comorbidity burden were associated with a higher proportion of cancer-unrelated death, according to the researchers.

“This article sheds an important light on the complex issue of predicting long term survival and the factors associated with it in NETs,” said Whitney S. Goldner, MD, Professor in the Division of Diabetes, Endocrinology, and Metabolism at the Fred & Pamela Buffett Cancer Center; and Vice-Chair of the NCCN Guidelines Panel for Neuroendocrine tumours.

“NETs are a very heterogeneous group of malignancies, so they require individualised treatment recommendations for each primary tumour site. It is insightful to learn about the different patterns of both cancer and non-cancer specific mortality specific to primary tumour site as well as other contributing factors. This article will be helpful to inform future guidelines regarding monitoring and treatment of different NETs and enable providers to provide NET site-specific counselling.”

Researchers also noted that examination of factors associated with cancer-specific and non cancer-related death showed that efforts to address cancer-specific death in NETs “should include special considerations for older adults and socioeconomically deprived patients to ensure they can access and receive care during their cancer journey.”

Source: National Comprehensive Cancer Network