OPINION

One of the most controversial aspects of Neuroendocrine Tumours (NETs) is the ‘benign vs malignant’ question. It’s been widely debated, and it frequently patrols the various patient forums and other social media platforms. It raises emotions and it triggers many responses ….. at least from those willing to engage in the conversation. At best, this issue can cause confusion, at worst, it might contradict what new patients have been told by their physicians (….or not been told). This post will not cover Neuroendocrine Carcinoma which by standard cancer nomenclature definition is malignant.

Any standard cancer nomenclature definition of the word ‘tumour’ will confirm the definition of the word tumour means it can either be benign or malignant. However, and while I’m sure there are benign NETs, the key statement to explain any slow-growing or indolent NET is that they all have malignant potential – thus why surveillance and follow-up are really important. This was the key factor in the changes found in the 2010 Digestive System World Health Organisation (WHO) classification system from the previous ‘flaky’ version. This reinforcement of the malignant potential of all NETs was duplicated in the recent 2017 Endocrine System and 2019 Digestive System equivalents, which is now proposed as a classification scheme for all NETs (see below).

“Carcinoid”

Of course, we are not helped by the continued use of the term Carcinoid which decodes to ‘Cancinoma Like’ – that is potentially regressing the work of those specialists who are trying to undo over 100 years of complacency in the medical world (….. and it’s not really the type of awareness we need). The word is gradually being erased from NET nomenclature and the recent 2018 proposal by the International Agency for Research on Cancer (IARC) and WHO NET expert consensus panel to ditch it from the remaining versions of out of date WHO classifications (e.g. Pulmonary/Lung, Pituitary, Head & Neck, Genito-urinary, Adrenal and Paraganglia, Skin), is the final nail in the coffin for Carcinoid. RIP Carcinoid. This also supports our awareness issues with the media reporting the wrong cancer types based on anatomy of the primary tumour.

Dear Doctors, Patient Advocates, Patients ….. Please stop using the word, it’s not helpful!

I’ve lost count of the stories from Neuroendocrine Cancer patients who have been told their tumour was benign but then returned to specialists at a later stage with incurable and metastatic cancer. There are doctors who clearly do not understand NETs and/or are not aware of the changes in WHO classification schemes from 2010 onwards. Sure, some will prove to be ‘benign’ in nature and may not cause many issues but any Ki-67 below 3% is a formal cancer grade of a Neuroendocrine Neoplasm. I accept that it’s currently difficult to work out which cases will turn more aggressive and when, thus why surveillance and follow-up are really important and also why patients should be seeing doctors who understand NETs. More sensitive molecular markers assisting doctors in decision-making will be welcome at some point in the future.  Worth also noting that many slow-growing and indolent tumours can still often produce troublesome NET syndromes.

I’ve even heard one patient story where it was claimed a doctor called a metastatic NET case benign! Any standard cancer nomenclature definition of ‘benign’ on any respectable cancer site will include the statement that they do not spread to other parts of the body. The NET patient world is full of slow-growing Grade 1 Stage 4 patients.  By dint of the stage number, they’re all malignant.

Read more detail in the articles below as these issues are inextricably linked.

I’m sure there are scenarios in all cancers where tumours can be benign and will never harm the person but if a doctor says you have a Neuroendocrine Tumour and not to worry because it’s benign, ask questions.  Start with “how do you know it will never turn malignant” and “what will be done going forward to check”. This is particularly important in cases of Small Intestine and Pancreatic NETs where there is a greater risk of spread than other NET types.  

I also acknowledge that many slow-growing localised NETs have much less prevalence for spread, i.e. Appendiceal NET, Rectal NET, and to a certain extent atypical Lung NET.  Epidemiological data confirm these have less risk of spreading and there are curative scenarios in completed removing the localised primary with the right margins. 

‘Benign vs Malignant’.
‘Carcinoid vs Neuroendocrine’
‘The Invisible NET Patient Population’
‘Staging and Grading’

Thanks for listening