Goblet cell carcinomas (GCC) are rare neuroendocrine tumours that develop in the appendix. More specifically, they develop in goblet cells, which are responsible for mucus secretion and production. The mucus acts as a protective layer in the intestines.
Neuroendocrine cancers are a complex group of tumours that develop in the neuroendocrine system, which is responsible for regulating important bodily functions such as heart rate, blood pressure and metabolism. They most commonly develop in the gastro-intestinal tract, pancreas, and the lungs; however, they can develop anywhere in the body. These tumours develop from neuroendocrine cells, which are responsible for receiving signals from the nervous system and producing hormones and peptides (small proteins) in response.
GCCs demonstrate a unique combination of both neuroendocrine cells and adenocarcinoma cells, which are cancerous cells that develop from mucus-producing cells. They tend to be more aggressive than classic neuroendocrine tumours, but are classified and staged as carcinomas of the appendix.
This type of cancer is diagnosed equally in males and females, and is generally diagnosed in people between the ages of 50-60. However, anyone can develop this disease.
Treatment
If a GCC is detected, it will be staged and graded based on size, metastasis (whether the cancer has spread to other parts of the body) and how the cancer cells look under the microscope. Staging and grading helps your doctors determine the best treatment for you.
Cancers can be staged using the TNM staging system:
- T (tumour) indicates the size and depth of the tumour.
- N (nodes) indicates whether the cancer has spread to nearby lymph nodes.
- M (metastasis) indicates whether the cancer has spread to other parts of the body.
This system can also be used in combination with a numerical value, from stage 0-IV:
- Stage 0: this stage describes cancer cells in the place of origin (or ‘in situ’) that have not spread to nearby tissue.
- Stage I: cancer cells have begun to spread to nearby tissue. It is not deeply embedded into nearby tissue and had not spread to lymph nodes. This stage is also known as early-stage cancer.
- Stage II: cancer cells have grown deeper into nearby tissue. Lymph nodes may or may not be affected. This is also known as localised cancer.
- Stage III: the cancer has become larger and has grown deeper into nearby tissue. Lymph nodes are generally affected at this stage. This is also known as localised cancer.
- Stage IV: the cancer has spread to other tissues and organs in the body. This is also known as advanced or metastatic cancer.
Cancers can also be graded based on the rate of growth and how likely they are to spread:
- Grade I: cancer cells present as slightly abnormal and are usually slow growing. This is also known as a low-grade tumour.
- Grade II: cancer cells present as abnormal and grow faster than grade-I tumours. This is also known as an intermediate-grade tumour.
- Grade III: cancer cells present as very abnormal and grow quickly. This is also known as a high-grade tumour.
Once your tumour has been staged and graded, your doctor may recommend genetic testing, which analyses your tumour DNA and can help determine which treatment has the greatest chance of success. They will then discuss the most appropriate treatment option for you.
Treatment is dependent on several factors, including location, stage of disease and overall health.
Treatment options for GCCs may include:
- Surgery, potentially including:
- Total appendectomy (complete removal of the appendix).
- Right hemicolectomy (removal of half of the large intestine/colon on the right side near where the appendix is located).
- Radiation therapy.
- Chemotherapy.
- Targeted therapies.
- Clinical trials.
- Palliative care.
For more information on treatment options, please refer to the Rare Cancers Australia Treatment Options page.
Risk factors
Because of how rare GCCs are, there has been limited research done into the risk factors for this disease. However, some studies have indicated that schistosomiasis (tropical parasite) may have a link to GCC.
Early symptoms
People who have GCC may experience some of the following symptoms:
- Appendicitis.
- Abdominal pain/distention (swelling).
- Bowel obstruction (blockage of the bowels).
- Abdominal lump.
- Gastrointestinal bleeding.
- Intussusception (part of the intestine slides into another part of the intestine).
Not everyone with the symptoms above will have cancer, but see your general practitioner (GP) if you are concerned.
Diagnosis/diagnosing
If your doctor suspects you have a GCC, they will order a range of diagnostic tests to confirm the diagnosis, and refer you to a specialist for treatment. In many cases, GCCs are diagnosed during an appendectomy to treat an appendicitis.
Physical examination
Your doctor will collect your overall medical history, as well as your current symptoms. Following this, they may examine your body to check for any abnormalities.
Imaging & blood tests
The doctor will take images of your body using magnetic resonance imaging (MRI), a computed tomography scan (CT scan), x-ray, and/or positron emission tomography (PET scan), depending on where it is suspected the cancer is. The doctor may also look at other parts of the body and looks for signs of metastasis. Additionally, a blood test may be taken to assess your overall health and help guide treatment decisions.
Biopsy
Once the location(s) of the cancer has been identified, the doctor will perform a biopsy to remove a section of tissue using a needle. The tissue sample will then be analysed for cancer cells.
Prognosis (Certain factors affect the prognosis and treatment options)
While it is not possible to predict the exact course of the disease, your doctor may be able to give you a general idea based on rate and depth of tumour growth, susceptibility to treatment, age, overall fitness, and medical history. Generally, early-stage GCCs have good prognosis and survival rates. However, if the cancer is advanced and has spread, the prognosis may not be as good and there may be a higher risk of cancer recurrence.
References
Some references are to overseas websites. There may be references to drugs and clinical trials that are not available here in Australia.