Appendix Cancer

Appendix cancer, or appendiceal cancer, arises when the cells of the appendix mutate and proliferate uncontrollably, forming a tumor. It is often discovered during appendicitis surgery or unrelated imaging tests. Smaller tumors have a lower tendency to spread, while larger ones typically require more aggressive treatment.

Appendix Cancer Abridged

What is Appendix Cancer?

Appendix cancer is a rare form of cancer that occurs when cells in the appendix undergo mutations, leading to uncontrolled growth. The appendix is a small pouch in the digestive system located at the junction of the large and small intestines. Its function is not fully understood, but it may play a minor role in the immune system’s functions, or it could be an entirely redundant vestigial organ.

Types of Appendix Cancer

Appendiceal Adenocarcinoma: Originates in the glandular tissue of the appendix. 

Variants include:

• Mucinous Adenocarcinoma: Produces mucin and typically remains within the abdomen.
• Colonic-Type Adenocarcinoma: Resembles colon cancer, emerging at the appendix base.
• Signet Ring Cell Adenocarcinoma: A rare form characterized by cells with a signet ring appearance.
• Goblet Cell Adenocarcinoma: Combines features of adenocarcinoma and neuroendocrine tumors.

Appendiceal Neuroendocrine Tumors: Generally slow-growing tumors that affect neuroendocrine cells, which regulate hormone release in response to nerve signals.

Prevalence

Appendix cancer is extremely rare, affecting about 1 to 2 people per million annually in the United States.

Symptoms of Appendix Cancer

Appendix cancer might not show the following symptoms until it spreads:

• Appendicitis-like pain
• Abdominal bloating or fluid buildup
• Increased waist size
• Abdominal or pelvic pain
• Changes in bowel habits
• Nausea and vomiting
• Early satiety (feeling full quickly)

In some cases, it can be associated with pseudomyxoma peritonei (PMP), where mucin-producing cancer cells cause abdominal swelling.

Causes of Appendix Cancer

The exact cause of appendix cancer is unclear, but it begins when cells in the appendix mutate and multiply excessively.

Risk Factors

• Age: Most common between ages 40 and 60.
• Sex: More prevalent in individuals assigned female at birth.
• Smoking: Increases general cancer risk. Appendix cancer is no exception.
• Medical History: Conditions like atrophic gastritis, pernicious anemia, and Zollinger-Ellison syndrome.
• Family History: There may be a genetic predisposition, though definitive hereditary links are uncertain.

Diagnosis

Diagnosis often occurs after an appendectomy due to how the cancer shares symptoms with appendicitis. Further testing methods are as follows:

• Imaging Tests: CT scans or MRIs to detect tumors and assess possible spread.
• Laparoscopy: Allows a direct view and imaging of the appendix. Minimally invasive.
• Biopsy: Tissue sampling to confirm the presence of cancer.
• Blood Tests: Evaluate protein levels indicative of cancer progression.

Staging

Staging informs treatment strategies and prognosis, differing based on the tumor type:

• Appendiceal Adenocarcinomas: Staged using the TNM system, which accounts for tumor size, lymph node involvement, and metastasis.
• Appendiceal Neuroendocrine Tumors: Staging is based on tumor grade and the potential for surgical removal.

Treatment

Surgical Treatments

• Appendectomy: Removal of the appendix for small tumors.
• Hemicolectomy: Partial removal of the colon and lymph nodes for larger tumors.
• Cytoreductive Surgery: Extensive tumor removal in cases of widespread abdominal cancer.

Drug Treatments

• Chemotherapy: For post-surgery or if the tumors can’t be fully removed. 
• HIPEC: Heated chemotherapy administered during surgery to enhance its effectiveness.
• Targeted Drug Therapy: Drugs like cetuximab and bevacizumab target specific cancer-promoting genes or proteins.

Treatment plans are individualized based on tumor characteristics, stage, and patient health.