Although less common, neuroendocrine cancer is unusually aggressive in Asians and is often overlooked because the symptoms are common to many other diseases.
Neuroendocrine cancer occurs in the cells of the neuroendocrine system. It is an insidious invader which causes a wide range of symptoms that could be attributed to other diseases, making diagnosis difficult.
The neuroendocrine system is a diffuse one that runs throughout the body, and its cells are present in organs such as the pituitary, pineal, thyroid, parathyroid and adrenal glands, the lungs, the pancreatic islets, the stomach, small and large intestines and the ovaries. These cells receive messages from the nervous system and respond by making hormones.
Certain changes in the neuroendocrine cells cause tumours to form, and some may become cancerous. When this happens, the symptoms depend on where the cancerous cells are. These cancers disrupt important hormonal functions or produce hormones in excessive amounts resulting in severe symptoms and complications. For instance, intestinal neuroendocrine tumours may cause severe episodes of diarrhoea, abdominal distension and discomfort. The cancer can also trigger the excessive release of hormones such as serotonin and cause heart valve damage.
A complex diagnosis
Since the cancer can originate in more than 40 places and cause a wide range of non-specific symptoms, it is often misdiagnosed as irritable bowel syndrome, ulcers, anxiety, asthma or even menopause. On average it can take five to seven years to accurately pinpoint the disease, by which time the tumours can be very large and could have spread to other tissues and organs in the body. It is, therefore, crucial to spot persistent symptoms and seek advice.
Because of the need to rule out other health problems, diagnosis of neuroendocrine cancer can be a long process. It typically includes a comprehensive medical history and physical examination, blood tests to spot any abnormal levels of glucose, stomach acid or hormones, and to identify cancer markers. Diagnostic imaging such as x-rays and scans may also be performed to detect tumours. One new scan, Gallium-68 DOTA-PEPTIDE scan, is especially useful in detecting neuroendocrine cancers. A radioactive isotope that targets only the cancer cells is injected into the body and can accurately reveal the mass. The scan has been found to more accurately evaluate patients before treatment and guide decisions on the best treatment option.
Targeted cures
Surgery may be done if the tumour is discovered early, however, this is often not the case in neuroendocrine tumours. Other technical treatment modalities may be considered when the tumour has spread to the liver, whereby a long catheter is passed through the blood vessels to the mass to deliver medications. This may involve small nanomolecular carrier molecules that deliver medications or cut off the blood supply ‘feeding’ it.
Fortunately, the advancement of new scientific discoveries and technologies has given us many new treatments. Neuroendocrine cancer commonly carries a visible molecular receptor that can be targeted by available medicines. This involves the use of targeted hormone receptors bringing medications for symptom control. Some novel cancer drugs behave like Trojan horses and can ‘unlock’ and enter the cancer cells to attack them from within. Others are targeted mini nuclear bombs that attach to specific molecular targets on cancer cells and detonate, delivering a small blast to destroy the cancer cells but leaving normal cells largely unharmed.
The key to successful neuroendocrine cancer survival is early detection. It underscores the need for increased awareness of the disease and earlier interventions for better outcomes.
For more information, visit Novena Cancer Centre, #09-41, 38 Irrawaddy Road. Singapore 329563. Tel: 6339 0233.
