What will happen long term?

A prognosis is a doctor’s opinion about how well someone will recover from an illness. The prognosis and survival rates of people with neuroendocrine tumours (NETs) depend on several factors listed here.

• Site – where the primary tumour(s) started in your body
• Metastasis – whether the cancer has spread to other organs causing secondary tumours or secondary cancer
• Size – how large the tumour is
• Symptoms – how it affects you physically and emotionally

• Whether the tumour produces excess hormones (functioning tumours) or not (non-functioning tumours)
• Stage – how advanced the cancer is
• Grade – how fast or slow it is growing and how well differentiated the tumour is
• Complications – what other medical conditions it may have caused

Other factors that will affect what will happen in the long term are your health in general and whether or not you have any other medical conditions.

To help determine what treatment may be best for a particular situation, doctors often stage and grade tumours.

Cancer staging – describes how far the cancers has spread in the body. Cancer stages commonly range from 1 to 4, with the higher the number indicating that the cancer is more widespread.

• Stage 1 NETs are confined to the area where they originated
• Stage 2 NETs have spread to the surrounding cells or tissue
• Stage 3 NETs have spready beyond the surrounding tissues and to nearby lymph nodes
• Stage 4 NETs have spread to another place in the body, including the lymph nodes

Cancer grading – gives an indication of how quickly or aggressively tumours are growing and how likely they are to spread. The rate at which cancer cells are growing is measured using the ‘Ki67 index’.

There are three cancer grades that describe how neuroendocrine cancer cells look under the microscope in comparison to normal cells.

• Grade 1 (G1) is where the cancer cells multiply slowly – the cells are well differentiated (look like normal cells) and the Ki67 index is less than 3%.
• Grade 2 is where the cancer cells multiply a little faster. The NET’s cells remain well-differentiated but the Ki67 index is between 3% and 20%.
• Grade 3 is where the cancer cells multiply more quickly, the cells are still well-differentiated, but the Ki67 is above 20%. and

NET refers to well differentiated tumours and can be G1, G2 or G3, depending on the Ki67 proliferation index.

Neuroendocrine Carcinomas (NEC) refers to poorly differentiated (do not look like normal cells) tumours that are rapidly-growing, aggressive cancers with a high Ki67 index.

NETs are usually classified according to their location in the body.

The information provided by staging and grading may give clues to the likely long-term outcome for a patient but it is important to note that having a high stage or grade alone does not necessarily mean that there is likely to be a worse outcome.

For example, someone with stage IV, grade 1 NETs may live many years with treatment as their cancer is relatively slow growing despite being large or spread throughout the body.