Most people have heard of appendicitis, but fewer know that cancer can develop in the appendix.
Appendiceal cancer is one of the rarest forms of gastrointestinal cancer, with only about 3,000 new cases diagnosed each year in the United States. It usually develops slowly and often causes few or no symptoms in its early stages. In fact, many appendix cancers are discovered unexpectedly after an appendectomy for suspected appendicitis.
Despite its rarity, appendix cancer is often treatable, especially when it's found early and treated aggressively. Overall survival rates range from 60% to 90% at five years. However, the survival rate for advanced cases can be much lower.
Types and subtypes of appendix cancers
Appendix cancer includes several different tumor types that behave differently and require different treatments, and survival is strongly influenced by subtype, grade and stage. Some appendix cancers exist on a spectrum of indolent or aggressive behavior. In those cases, the indolent, or slow growing, grade 1, versions of these cancers are sometimes referred to as “tumors.”
The three main types of appendiceal tumors include:
- Mucinous appendiceal adenocarcinoma (high grade), or low grade appendiceal mucinous tumors (LAMN), (epithelial cancers) of the appendix
- Non-mucinous adenocarcinomas of the appendix
- Appendiceal neuroendocrine tumors (NET), or appendiceal neuroendocrine carcinomas
These tumors can be classified as low, medium, or high grade tumors depending on how the cancerous cells look under a microscope.
Appendiceal adenocarcinoma grows from cells that line the appendix and help make mucin — a building block of mucus — and other digestive fluids. Neuroendocrine tumors of the appendix, the most common type of appendiceal cancer, grow from cells that release hormones that aid digestion.
Mucinous neoplasm is a rare form of appendiceal adenocarcinoma typically found during appendectomy.
Overall, the five-year survival rate for neuroendocrine tumors of the appendix is 90%, and for early-stage mucinous appendiceal adenocarcinoma, it is 70%. However, stage 4 mucinous appendiceal cancer that has spread to other parts of the body has a five-year survival rate of 30%.
For early-stage low-grade appendiceal mucinous neoplasms (LAMN), survival is high at 97%. Even when found at stage 4 with spread into the peritoneum (abdominal cavity), survival can be as high as 79% with aggressive treatment.
Because these tumors vary so much, treatment is tailored to the specific type, grade and stage of the cancer.
How is appendix cancer treated?
Surgery is central to treating nearly every type of appendix cancer.
For some early, low-grade cases, removing the appendix alone may be all that's needed. More advanced cancers may require removal of part of the colon, nearby lymph nodes or other affected tissues, as well as chemotherapy before or after surgery.
When the cancer has spread into the abdominal cavity, cytoreductive surgery (CRS), a specialized operation to remove all visible tumors, is offered along with hyperthermic intraperitoneal chemotherapy, or HIPEC.
HIPEC is a treatment in which a heated solution containing anticancer drugs is infused directly into the abdominal cavity. It is administered after CRS to kill any remaining cancer cells.
Why specialized care matters
Because appendix cancer is so uncommon, and treatment is contingent on the specific subtype, grade and stage, early evaluation by a multidisciplinary cancer team is critical to optimizing outcomes. Coordinated care between surgical and medical oncology can help ensure patients receive the most effective treatment for their specific diagnosis.
At Northside Hospital Cancer Institute, the focus is on providing comprehensive cancer care that combines leading-edge treatments with the support and compassion patients need throughout their cancer journey.
LEARN MORE ABOUT APPENDIX CANCER TREATMENT AT NORTHSIDE.
