Appendix cancer

Appendix cancer is a rare type of cancer that begins when cells in the appendix grow out of control. The appendix is a small pouch attached to the first part of the large intestine. Because appendix cancer is so uncommon, many people only find out they have it after having surgery to remove the appendix to treat appendicitis. But they find out that what their healthcare professionals thought was appendicitis was really appendix cancer. Appendix cancer is sometimes called appendiceal carcinoma or appendiceal cancer.

There are several types of appendix cancer, and each one behaves differently. Some types grow very slowly and may stay in the appendix for years. Others can spread more quickly to the lining of the abdomen or to other organs. How serious it is depends on the cancer type, how far it has spread, and how the cells look under a microscope.

Slow-growing, low-grade appendix cancers can often be cured with surgery. But more-aggressive ones may need additional treatment, such as traditional chemotherapy or a specialized procedure called hyperthermic intraperitoneal chemotherapy (HIPEC).

Even though appendix cancer is still very rare — affecting only about 1 to 2 people per 100,000 each year — it has been diagnosed more often in recent years, including in younger adults. Many people live for years after diagnosis, especially when the cancer is found early or can be completely removed with surgery.

Types

Appendix cancer can begin in different kinds of cells inside the appendix. These cancers are broadly grouped into two main types: epithelial appendix cancers and neuroendocrine appendix cancers. Each behaves differently and may require different treatments.

Epithelial appendix cancers

Epithelial cancers start in the cells that line the inside of the appendix. These cells typically help make a jellylike fluid, called mucus, that protects the lining of the digestive tract. When these tumors grow, many produce large amounts of mucus. If the appendix ruptures or leaks, this mucus can spread through the abdomen and cause a condition called pseudomyxoma peritonei (PMP).

Epithelial appendix cancers include a few subtypes:

• Adenocarcinomas. These cancers start from the gland cells that line the appendix. There are two main types: mucinous and nonmucinous. Nonmucinous type also is called colonic type. Adenocarcinomas are often treated with a more extensive surgery, such as removing part of the colon.
• Appendiceal mucinous neoplasms (AMNs). These tumors make a jellylike fluid called mucus. AMNs can be low-grade (LAMN) or high-grade (HAMN). LAMN tumors grow slowly, while HAMN tumors are more likely to spread.
• Goblet cell adenocarcinomas. These rare tumors have features of both gland-forming and hormone-producing cells. They tend to grow faster than neuroendocrine tumors and often need more-extensive surgery and sometimes chemotherapy.
• Signet ring cell carcinomas. This is a rare and aggressive type of adenocarcinoma. The cancer cells look like rings under a microscope and tend to spread early. These usually require intensive treatment.

Neuroendocrine appendix cancers

Neuroendocrine tumors (NETs), sometimes called carcinoid tumors, start in hormone-producing cells. These cells help regulate digestion. NETs are the most common type of appendix tumor and are often found unexpectedly after surgery for suspected appendicitis. Many NETs grow slowly and can be treated successfully by removing the appendix. Larger tumors or those that involve lymph nodes may require additional treatment and follow-up.

Appendix cancer can be hard to detect because many people don't have symptoms at first. In fact, it's often found by accident during surgery for appendicitis or another abdominal problem. When symptoms do appear, they can be mild and easy to mistake for other conditions.

If the cancer grows larger, symptoms may include:

• Pain in the lower right side of the belly. This is the same area where appendicitis pain usually happens.
• A growing belly size caused by mucus or fluid buildup inside the abdomen, which may happen with mucinous tumors or a condition called pseudomyxoma peritonei.
• Nausea or vomiting.
• Feeling full soon after you eat.

When to see a doctor

Because these symptoms can be caused by many other health problems, it's important to talk with a healthcare professional if symptoms last more than a few days or seem unusual for you. Early evaluation and imaging can help find the cause and, if needed, guide treatment.

Medical experts don't yet know the exact cause of appendix cancer. It happens when healthy cells in the appendix begin to change and grow in ways they shouldn't. Over time, these cells can form a tumor.

Researchers believe these changes may begin in the DNA inside cells, but the reason this happens is still not clear. Unlike some cancers, appendix cancer has no known lifestyle or environmental cause.

In most people, appendix cancer seems to occur by chance. It's important to remember that nothing you did or didn't do caused it. Scientists continue to study why certain appendix cells become cancerous and how to detect these changes early.

Although the cause of appendix cancer isn't known in most cases, research shows some associations with older age and inherited genetic variations. These factors do not guarantee that someone will develop appendix cancer. They merely highlight areas where risk might be slightly higher. Because this cancer is so rare and understudied, definitive risk factor profiles are not yet established.

Appendix cancer can lead to problems in the belly and other parts of the body, especially if it spreads or causes a buildup of mucus or fluid. Some possible complications include:

• Pseudomyxoma peritonei (PMP). Some appendix tumors make a jellylike mucus that can leak into the abdomen. This mucus can fill the belly and put pressure on the organs, leading to bloating, discomfort or trouble eating.
• Spread of cancer, called metastasis. If the cancer moves to other areas — such as the lining of the abdomen, ovaries or liver — it can cause new symptoms such as swelling, weight loss or fatigue.

These complications can typically be treated or managed. Regular follow-up and imaging help healthcare professionals find and address problems early.

Appendix cancer is difficult to diagnose early because it usually doesn't cause clear or specific symptoms. The appendix is a small organ tucked deep in the lower right side of the abdomen, so small tumors can grow there for a long time without being noticed. Many people learn they have cancer only after surgery for appendicitis or another abdominal condition.

If a healthcare professional suspects appendix cancer, several steps can help make the diagnosis:

• Medical history and exam. Your health professional usually asks about your symptoms, family history and any past health problems. During the exam, typically your abdomen is examined for swelling or tenderness.
• Imaging tests. Computerized tomography (CT) or MRI scans create detailed pictures of your abdomen and pelvis to look for tumors, fluid buildup or signs that the cancer has spread. Ultrasound can sometimes detect an enlarged appendix or fluid, especially when appendicitis is suspected.
• Surgery and biopsy. The most common way appendix cancer is found is during surgery to remove the appendix, called an appendectomy. After surgery, a pathologist examines the tissue under a microscope to see if cancer cells are present and to determine the exact type and grade.
• Lab and genetic tests. Blood tests may be used to check levels of chemicals made by cancer cells, called tumor markers. This can help medical professionals track treatment or recurrence. Some people also may benefit from genetic testing if there's a family history of cancer or if the tumor type suggests an inherited risk.

Each of these steps helps your care team understand the exact type and stage of your cancer so your care team can create the best treatment plan for you.

Treatment for appendix cancer depends on the type of tumor, how advanced it is, and your overall health. Your care team will design a plan that's right for you.

The main treatment options include:

Surgery or other procedures

Surgery is the main treatment for most types of appendix cancer. The goal is to remove the tumor and any nearby tissue where cancer cells may have spread. The exact type of surgery depends on the tumor's size, location and whether it has spread beyond the appendix.

• Appendectomy. If the cancer is small and limited to the appendix, removing the appendix alone may be enough. This is often the case for slow-growing tumors such as neuroendocrine tumors (NETs) or low-grade mucinous neoplasms (LAMNs).
• Right hemicolectomy. If the tumor is larger, high-grade or near the base of the appendix, surgeons may remove part of the colon and nearby lymph nodes to make sure all the cancer is gone.
• Cytoreductive surgery (CRS). When appendix cancer has spread throughout the abdomen, surgeons perform a special operation to remove as much visible cancer as possible. Even if all the cancer can't be removed, this helps other treatments work better. During the surgery, the surgeon may remove tumors from the lining of the abdomen, called the peritoneum, and sometimes parts of nearby organs. CRS is sometimes called debulking surgery. This procedure is often followed by a specialized treatment called hyperthermic intraperitoneal chemotherapy (HIPEC).

Therapies

In addition to surgery, some people with appendix cancer benefit from treatments that use medicine to destroy or control cancer cells. These therapies include:

• Hyperthermic intraperitoneal chemotherapy (HIPEC). HIPEC is a specialized cancer treatment used for cancers that have spread to the lining of the abdominal cavity, known as the peritoneum. CRS is typically done before HIPEC. After CRS, the abdominal cavity is bathed with heated chemotherapy medicine to target any remaining microscopic cancer cells. This combined approach can significantly reduce the risk of cancer recurrence, improve survival rates and even offer a potential cure for some people.
• Traditional chemotherapy. Chemotherapy treats cancer with strong medicines. For advanced or high-grade cancers that have spread beyond the abdomen, chemotherapy given through a vein may help shrink or slow the cancer.

• Targeted therapy or immunotherapy. For some people with advanced cancer or for those who are not able to have CRS, doctors may recommend medicines that target specific changes in the cancer or help the immune system attack it. These options include treatments that block tumor blood vessel growth, called antiangiogenesis therapy. It may also involve immunotherapy for tumors with certain genetic features.

  These therapies are based on early studies in appendix cancer and research from other digestive system cancers. These therapies are typically only used in specialized centers or clinical trials.

Surveillance

For some slow-growing or completely removed tumors, your healthcare professional may recommend regular checkups and scans instead of immediate further treatment.

There is a higher risk of colon cancer in people with appendiceal tumors, so a colonoscopy is recommended if one has not been done recently.

Alternative medicine treatments won't kill cancer cells. But some alternative medicine treatments may help you cope with the side effects of cancer treatment. Your healthcare team can treat many side effects, but sometimes medicines aren't enough. Alternative treatments may offer additional comfort.

Options for common side effects include the following:

• Anxiety — massage, meditation, hypnosis, music therapy, exercise or relaxation techniques.
• Fatigue — gentle exercise or tai chi.
• Nausea — acupuncture, hypnosis or music therapy.
• Pain — acupuncture, massage, music therapy or hypnosis.
• Sleep problems — yoga or relaxation techniques.

While these options are generally safe, talk with your healthcare team first to be sure that alternative medicine options won't affect your cancer treatment.

People facing a serious illness often say they feel worried about the future. With time, you'll find ways to cope with your feelings, but you may find comfort in these strategies:

• Ask questions about appendix cancer. Write down questions you have about your cancer. Ask these questions at your next appointment. Also ask your healthcare team for reliable sources where you can get more information.

  Knowing more about your cancer and your treatment options may make you more comfortable when you make decisions about your care.

• Stay connected to friends and family. Your cancer diagnosis can be stressful for friends and family too. Try to keep them involved in your life.

  Your friends and family will likely ask if there's anything they can do to help you. Think of tasks you might like help with. For example, you may ask a friend to be there for you when you want to talk. You may ask for help caring for your home if you have to stay in the hospital.

  You may find comfort in the support of a caring group of your friends and family.

• Find someone to talk with. Find someone you can talk to who has experience helping people facing a life-threatening illness. Ask your healthcare team to suggest a counselor, clergy member or medical social worker you can talk with. For support groups, contact the American Cancer Society or ask your healthcare team about local or online groups.

Make an appointment with a doctor or other healthcare professional if you have any symptoms that worry you.

If your health professional thinks you have appendix cancer, you may be referred to a specialist. Often this is a surgeon or doctor who treats digestive diseases, called a gastroenterologist. You also may be referred to a doctor who specializes in treating cancer, called an oncologist.

Because appointments can be brief, it's a good idea to be prepared. Here's some information to help you get ready.

What you can do

• Be aware of any pre-appointment restrictions. At the time you make the appointment, be sure to ask if there's anything you need to do in advance. For example, you might need to restrict your diet.
• Write down symptoms you're experiencing, including any that may not seem related to the reason for which you scheduled the appointment.
• Write down key personal information, including major stresses or recent life changes.
• Make a list of all medicines, vitamins or supplements you're taking and the doses.
• Take a family member or friend along. Sometimes it can be difficult to remember all the information provided during an appointment. Someone who accompanies you may remember something that you missed or forgot.
• Write down questions to ask your healthcare team.

Your time with your healthcare team is limited. Prepare by making a list of questions. List your questions from most important to least important in case time runs out. For appendix cancer, some basic questions to ask include:

• What is the stage of my cancer?
• What other tests do I need?
• What are my treatment options?
• Is there one treatment that's best for my type and stage of cancer?
• What are the potential side effects for each treatment?
• Should I seek a second opinion? Can you give me names of specialists you recommend?
• Am I eligible for clinical trials?
• Are there brochures or other printed material that I can take with me? What websites do you recommend?
• What will determine whether I should plan for a follow-up visit?

What to expect from your doctor

Be prepared to answer questions about your symptoms and your health, such as:

• When did you begin experiencing symptoms?
• Have your symptoms been continuous or occasional?
• How severe are your symptoms?
• What, if anything, seems to improve your symptoms?
• What, if anything, appears to worsen your symptoms?

After a diagnosis of appendix cancer, healthcare professionals perform tests to learn how far the disease has spread. This process is called staging. Knowing the stage helps your healthcare team design the best treatment plan for your specific type of tumor.

Tests used for staging may include blood work and imaging scans. These pictures show the size and location of the tumor and whether it has spread to lymph nodes or other organs. Sometimes, surgery is needed to see exactly how much of the appendix and nearby tissue is affected.

How appendix cancer is staged

Appendix cancer is often staged using the American Joint Committee on Cancer TNM system. This system looks at three key areas:

• T (tumor). How deeply the tumor has grown into the wall of the appendix or surrounding tissue.
• N (nodes). Whether the cancer has spread to nearby lymph nodes.
• M (metastasis). Whether the cancer has spread to distant organs, such as the liver or lungs.

Stage 1

The cancer has grown into the deeper layers of the appendix wall but hasn't reached nearby lymph nodes or other organs. It is still localized and can usually be treated successfully with surgery, sometimes followed by closer monitoring.

Stage 2

The tumor has grown through the appendix wall and may involve nearby tissue, but it hasn't spread to lymph nodes or distant sites. Treatment often includes a larger surgery, such as a right hemicolectomy, to ensure complete removal.

Stage 3

The cancer has spread to nearby lymph nodes but not to distant parts of the body. It's considered regional disease. Surgery to remove the appendix and nearby lymph nodes is standard, and chemotherapy may be added to reduce the risk of recurrence.

Stage 4

This is the most advanced stage. The cancer has spread to distant organs, such as the liver, lungs or the lining of the abdomen, called the peritoneum. Treatment may include cytoreductive, also called debulking, surgery. It also may include hyperthermic intraperitoneal chemotherapy (HIPEC) and traditional chemotherapy to control growth and relieve symptoms. Hyperthermic is also known as heated chemotherapy.

Understanding a cancer's grade

Staging describes where the cancer is in the body, while grade describes how aggressive the cancer cells look under a microscope. Grade gives healthcare professionals a sense of how fast the tumor is likely to grow. Low-grade tumors tend to grow slowly, while high-grade tumors grow faster and are more likely to spread.

Looking ahead

Understanding your stage and grade helps your care team recommend the most effective treatment and follow-up plan. Many people with early-stage or low-grade appendix cancer do very well after surgery. Even with more-advanced disease, new treatments such as HIPEC have improved outcomes and quality of life.

The outlook for appendix cancer varies widely depending on the tumor type, grade and how far the cancer has spread at diagnosis. Because this disease is rare, survival rates are based on smaller studies and registry data compared with more common cancers. Still, the information available helps healthcare professionals estimate outcomes and guide treatment planning.

When appendix cancer is found early and limited to the appendix, surgery often provides an excellent chance of long-term survival. If the cancer has spread to lymph nodes or the lining of the abdomen, called the peritoneum, the outlook depends on how completely the cancer can be removed and how well it responds to treatment.

Survival statistics

Survival statistics come mainly from national databases and registry studies, including the Surveillance, Epidemiology and End Results (SEER) program. Many studies report survival using a method called summary staging. Summary staging groups tumors into three categories:

• Localized, meaning cancer is limited to the appendix.
• Regional, meaning cancer has spread to nearby tissues or lymph nodes.
• Distant, meaning cancer has spread to organs such as the liver or throughout the abdomen.

For low-grade, early-stage appendix cancers, SEER data show that five-year overall survival ranges from about 68% to nearly 97%. If the cancer has spread or is high grade, survival rates may be lower. It's important to remember that these numbers describe trends and cannot predict individual outcomes.

Localized appendix cancer

Localized disease is limited to the appendix and has not spread to nearby lymph nodes or distant organs. SEER-based studies show that survival is highest at this stage, and many people do very well after surgery alone. Long-term outcomes are often excellent when the cancer is removed before it spreads.

Regional appendix cancer

Regional appendix cancer has spread to nearby tissues or lymph nodes. Survival is lower than in localized disease, but many people continue to live well with appropriate treatment. The outlook depends on the tumor's characteristics and whether complete removal of visible cancer is possible.

Distant appendix cancer

Distant, also called metastatic, appendix cancer means the disease has spread to areas such as the liver or the lining of the abdomen, called the peritoneum. Survival at this stage varies widely and depends on the tumor type and how well the cancer responds to treatment. SEER-based data show that survival is generally lowest at this stage compared with localized or regional disease.

Many people with distant spread can still live for several years when treatment includes cytoreductive surgery, especially when all visible cancer can be removed. In these situations, surgery and chemotherapy aim to control the cancer, relieve symptoms and support quality of life.

Looking ahead

These survival categories offer a helpful general framework, but they cannot predict any one person's outcome. Appendix cancer includes several different tumor types, each with its own behavior. Advances in diagnosis, surgery and systemic therapy continue to improve outcomes over time.