Appendix cancera disease where abnormal cells split without control and spread to other nearby body tissue and/or organs, also known as appendiceal cancer, is a rare malignancy developing from the appendix, a small, finger-shaped pouch connected to the caecum of the large bowelportion of the digestive system that digests food (small bowel) and absorbs salts and water (large bowel); also called intestines/intestine. It sits on the lower right side of the abdomenstomach, stomach area, belly, and has an unknown function within the body.
Appendix cancer is more common in women, and tends to be diagnosed between the ages of 40-60. However, anyone can develop this disease.
Types of Appendix Cancer
There are several types of appendix cancer, which are categorised by the types of cellsthe basic structural and functional unit of all living things they develop from.
Neuroendocrine Tumours (NETs)
Appendiceal NETs are a rare type of NET that develops in the appendix, however, they are the most common type of appendix cancer. These tumours often produce symptoms similar to those produced by an appendicitisinflammation of the appendix, and are often diagnosed during surgerytreatment involving removal of cancerous tissue and/or tumours and a margin of healthy tissue around it to reduce recurrence to remove the appendix (appendectomycomplete removal of the appendix). Appendiceal NETs are often found at the tip of the appendix, and can have a good prognosisto predict how a disease/condition may progress and what the outcome might be.
Goblet Cell Carcinoma (GCC)
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.
GCCs demonstrate a unique combination of both neuroendocrine cells and adenocarcinomacancer arising from mucus-producing glands in organs 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.
For more information on GCCs, please refer to the Rare Cancers Australia Goblet Cell Carcinoma (GCC) page.
Mucinous Adenocarcinoma
Mucinous adenocarcinomas are the second most common type of appendix cancer that develop from the mucus-producing glands in the appendix. These tumours produce mucin, which is a jelly-like substance found in the mucus that lines some organs. This mucin production can cause cancer cells to metastasise to other parts of the body, most commonly the peritoneumthe membrane that lines the abdominal cavity (a membrane that surrounds many abdominal organs). Mucinous adenocarcinomas are often diagnosed at a late stage of disease, and may not have as good of a prognosis as other types of appendix cancer.
Pseudomyxoma Peritonei (PMP)
Pseudomyxoma peritonei (PMP) is a rare tumoura tissue mass that forms from groups of unhealthy cells that causes a build-up of mucin in the abdomen or pelvis. It is often found in the appendix, and is associated with conditions such as mucinous adenocarcinomas. However, PMP can also develop in other organs, such as the large bowel or the ovary. While this type of cancer develops very slowly, it can put pressure onto nearby organs which may cause problems. PMP can have a good prognosis when caught early.
Colonic-type Adenocarcinoma
Colonic-type adenocarcinomas are rare types of appendix cancer that are often found in the base of the appendix. They behave similarly to colorectalrelating to the colon or rectum in the large bowel/intestine adenocarcinomas, which is the most common type of bowel cancer. Unlike other types of appendix cancer, colonic-type adenocarcinoma is slightly more common in men. While this type of cancer can be aggressive, it can have a good prognosis when caught early.
Signet Ring Cell Adenocarcinoma
Signet ring cell adenocarcinomas are very rare types of appendix cancer that are also found in mucus-producing cells in the appendix. However, these cells look distinctly different under the microscope due to unusually large cytoplasmic vacuoles that push the nucleus to the edge of the cell, forming a signet-ring shape. This type of cancer is often diagnosed late, and may not have as good of a prognosis as other types of appendix cancer.
LAMN and HAMN
Low-grade appendiceal mucinous neoplasms (LAMN) and high-grade appendiceal mucinous neoplasms (HAMN) are two different types of appendix tumours that are characterised by cellular appearance and tumour characteristics.
LAMN
Low-grade appendiceal mucinous neoplasms (LAMN), previously known as appendiceal mucinous cystadenomas, are rare tumours that develop from epithelial cells in the appendix. They do not tend to spread beyond the appendix, but they produce mucus causing an enlargement of the appendix and may cause pseudomyxoma peritonei if the appendix ruptures. As LAMNs are low-grade, they are generally slow growing and are often discovered by accident.
HAMN
High-grade appendiceal mucinous neoplasms (HAMN) are rare tumours that also develop from epithelial cells in the appendix. These tumours have high-grade features, and may develop more quickly than LAMN. HAMN is a recently described neoplasm, and as such there has been limited research done into this disease.
Treatment
If an appendix cancer is detected, it will be staged and graded based on size, metastasiswhen the cancer has spread to other parts of the body, also known as mets, and how the cancer cells look under the microscope. Stagingthe process of determining how big the cancer is, where it started and if it has spread to other areas 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 (nodea small lump or mass of tissue in your body) indicates whether the cancer has spread to nearby lymph nodessmall bean-shaped structures that filters harmful substances from lymph fluid.
- 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 tissuea group of cells that work together to perform a function.
- 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 localisedaffecting only one area of body 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 advancedat a late stage, far along or metastatic cancer.
Cancers can also be graded based on the rate of growth and how likely they are to spread:
- Gradea description of how abnormal cancer cells and tissue look under a microscope when compared to healthy cells 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 testinga procedure that analyses DNA to identify changes in genes, chromosomes and proteins, which can be used to analyse tumour DNA to help determine which treatment has the greatest chance of success, 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, age, stage of disease and overall health.
Treatment for appendix cancer may include:
- Surgery, potentially including:
- Appendectomy.
- Hemicolectomyremoval of a portion of the colon; can be the right side (right hemicolectomy) or the left side (left hemicolectomy).
- Cytoreductive surgeryremoval of all visible tumours in the abdominal cavity, often performed alongside hyperthermic intraperitoneal chemotherapy (HIPEC), often performed alongside hyperthermic intraperitoneal chemotherapy (HIPEC)an aggressive type of chemotherapy that involves applying chemotherapy that has been heated to 42 degrees Celcius to the abdominal cavity to kill cancer cells that may remain after tumour removal; often performed alongside cytoreductive surgery.
- Peritonectomyremoval of the peritoneum.
- Chemotherapya cancer treatment that uses drugs to kill or slow the growth of cancer cells, while minimising damage to healthy cells.
- Radiation therapya treatment that uses controlled doses of radiation to damage or kill cancer cells.
- Clinical trialsresearch studies performed to test new treatments, tests or procedures and evaluate their effectiveness on various diseases.
- Palliative carea variety of practices and exercises used to provide pain relief and improve quality of life without curing the disease.
Risk factors
Because of how rare appendix cancers are, there has been limited research done into the riskthe possibility that something bad will happen factors of this disease.
Symptoms
The symptoms of an appendix cancer often vary by subtype.
General Symptoms of Appendix Cancer
The general symptoms of appendix cancer include:
- Abdominal pain in the lower right quadrant (often caused by an appendicitis).
- Gradual increase in waist size.
- Ascitesa buildup of fluid in the abdomen.
- Bloating.
- Changes in bowel habits, potentially including constipationa condition where a person has difficulty passing faeces/stools or diarrhoeafrequent discharge of watery or loose stools from the body.
- Herniathe protrusion of organs or tissue through a weakened section of the abdomen.
- Ovarian massa growth of cells that come together to make a lump, may or may not be cancer/lump.
- Nauseato feel sick or likely to vomit and/or vomiting.
- Feeling full after eating little food.
Patients with mucinous adenocarcinomas, PMP, colonic-type adenocarcinomas, or signet-ring adenocarcinomas rarely experience additional symptoms to the ones listed.
Symptoms of Appendix NETs & Goblet Cell Carcinomas
In addition to the general symptoms, patients with an appendiceal NET or a GCC may also experience the following symptoms:
- Bowel obstructiona complete or partial blockage of the bowel/intestines.
- Abdominal lumps.
- Gastrointestinal bleeding.
- Intussusceptiona serious condition that occurs when part of the intestine slides into another part of the intestine causing a bowel obstruction.
Not everyone with the symptoms above will have cancer, but see your general practitioner (GP) if you are concerned.
Diagnosis
If your doctor suspects you have an appendix cancer, they may order the following tests to confirm the diagnosisthe process of identifying a disease based on signs and symptoms, patient history and medical test results and refer you to a specialist for treatment:
- Physical examinationan examination of your current symptoms, affected area(s) and overall medical history.
- Imagingtests that create detailed images of areas inside the body tests, potentially including:
- MRI (magnetic resonance imaging)a type of medical imaging that uses radiowaves, a strong magnet and computer technology to create detailed images of the body.
- CT (computed tomography) scana type of medical imaging that uses x-rays and computer technology to create detailed images of the body.
- Ultrasounda type of medical imaging that uses soundwaves to create detailed images of the body .
- Blood teststesting done to measure the levels of certain substances in the blood.
- Diagnostic laparoscopya minimally invasive surgical procedure that uses small incisions to access the body for procedures, often used for conditions that cannot be confirmed by scans and tests alone.
- Biopsyremoval of a section of tissue to analyse for cancer cells.
