28 October 2013

Doctors are calling for more awareness of neuroendocrine tumours because of their slow growth and vague symptoms, writes Kasmiah Mustapha

IT is a rare form of cancer that can grow slowly in the body and the symptoms will only present themselves years later. To make matters worse, most of the diagnoses are incidental as the symptoms are vague and, at times, mimic other conditions.

However, not everything is bad news when it comes to neuroendocrine tumours (NETs). While rare, it is not as aggressive as other forms of cancer. With treatment, patients can live years with a relatively good quality of life even when the tumours have spread.

NETs are tumours that arise from neuroendocrine cells. These are specialised cells throughout the body that release hormones into the blood when they are stimulated by the nerves. NET cancers develop when these cells undergo change causing them to divide uncontrollably and grow into an abnormal tissue mass (tumour).

Putrajaya Hospital consultant endocrinologist Dr Zanariah Hussein says the common area in which NETs can be detected is the gastrointestinal tract and these are often referred to as gastro-enteropancreatic (GEP) tumours.

“Sometimes the tumours don’t have symptoms. Patients may complain of abdominal pain, weight loss and diarrhoea and may go to a general practitioner for treatment and may often be misdiagnosed as irritable bowel syndrome or gastritis. More often than not, this results in a delay in the right diagnosis.

“These tumours are rare and we usually see about three new cases per year in Putrajaya Hospital, which is a referral centre for endocrinology and diabetes care.”

Dr Zanariah says she has been treating several patients with hormonal syndromes which, upon investigation were confirmed as pancreatic neuroendocrine tumour. The most common of these are insulin producing tumours where patients experience low blood sugar levels, which is rare, unless they are injecting insulin or taking medication for diabetes.

The patients also suffer from hypoglycaemia which may cause dizziness and fainting. Once the doctor has ruled out any medication causing the low blood sugar level, he has to investigate other issues.

THOROUGH CHECK

Patients are referred to a gastroenterologist, who will perform an endoscopic ultrasound to determine if there is a lesion in the pancreas. As the pancreas is located behind the stomach, an ultrasound is done through the stomach wall to find the exact location of the tumour.

“Neuroendocrine tumours vary, so most of the time, they are caught during routine check-ups such as endoscopy of the lower rectum.”

Sime Darby Medical Centre Subang Jaya consultant gastroenterologist Datin Dr Sharmila Sachithanandan says the challenge in diagnosing NETs is the way the symptoms present themselves. It is generally a silent tumour where the diagnosis will take an average of three to seven years. In addition, symptoms such as flushing, stomach pain, diarrhoea and bloating can mimic common diseases such as irritable bowel syndrome, thyroid diseases and anxiety.

As the tumour takes years to grow, initially the patient will not experience any of the symptoms. Once it has grown bigger or began to spread, the symptoms appear. As the symptoms can be non-specific and vague, NETs are often misdiagnosed.

“We need doctors to be aware of neuroendocrine tumours. They need to ask more questions when their patients come with these symptoms. If they ask in-depth about the patient’s problems, it may give them a clue that it could be a tumour.

“The public also need to be aware about it. They may not have neuroendocrine tumours but if they suffer from some of the symptoms for a long time, for example, more than six months and they are still not getting better after treatment, they should ask their doctors about the possibility of an underlying neuroendocrine tumour.”

A COMBINATION OF TESTS

Dr Sharmila says NETs are diagnosed through a combination of tests. These include blood tests, imaging modalities using CT and MRI scanning, endoscopy including endoscopic ultrasound (especially for the pancreas) and histological confirmation via biopsy. There is now a latest scanning technology using the Dotatate scan (a type of PET scan) which can detect the smallest of tumours.

“If the tumour is in the small bowel, it can be as small as 5mm which is difficult to detect with CT or MRI scan. But the Dotatate scan can detect it. The tumour can be very small but it can spread to other parts of the body, especially the liver.

“Unfortunately by the time the tumour is detected, it has spread. But there is still hope for survival as there are treatments available and with better outcome.”

For other types of cancer, if it has spread to other organs, that means it is already in stage four and the survival rate is slim. But with NETs, patients can survive for at least five to 10 years with a fairly good quality of life.

Dr Sharmila says raising awareness of NETs is needed because there are better diagnostic modalities and treatments available. The treatment for NETs are surgery or chemotherapy or a combination of both.

The approach to raising awareness is to look for subtle rare causes. The idea is “if you hear hoof beats, we always think it’s a horse but it could also be a zebra.”

“If doctors see a patient with vague symptoms of NETs, think about the possibility of the disease.”

Fast facts

• Neuroendocrine Tumours is the umbrella term for a group of unusual, often slow-growing cancers, which develop from cells in the diffuse endocrine system. They are found most commonly in the lung or gastrointestinal system, but they can also originate in other parts of the body such as the pancreas, ovary and testes.
• There are a number of different types of NETs and they all have a slightly different way of presenting themselves, both in terms of symptoms and how they look under a microscope.
• NETs symptoms can vary, depending on the location and biological properties. Very often, the symptoms are similar to other, more common conditions. Early symptoms may include vague tiredness or digestive complaints, or there may be no symptoms at all.
• NET tumours can produce abnormally large amounts of hormones while some have a related syndrome, such as carcinoid syndrome. This means the hormones that are secreted cause noticeable symptoms like flushing, diarrhoea, cramps, asthma-like wheezing, heart problems and skin changes.
• A NET cancer patient should ideally be treated by a multidisciplinary team that normally will include gastroenterologists, surgeons, oncologists, endocrinologists, radiologists, nuclear medicine specialists, histopathologists and clinical nurse specialists to ensure the best outcome.
• When caught at an early stage, NET cancers can often be cured with surgery. As with all cancers, if a surgical cure is possible, this should be the first line of treatment. Unfortunately, many patients are diagnosed later on, when the cancer has spread to other parts of the body. However, even when the tumours have spread, the disease and its symptoms can often be controlled for many years.

Source: http://netcancerday.org

By Kasmiah Mustapha

This article was first published in www.nst.com.my on 8 January 2013.