نظرة عامة
Stage 4 colon cancer is cancer that starts in the colon and spreads to other parts of the body. Stage 4 colon cancer also is known as metastatic, late-stage or distant colon cancer.
Up to half of the people diagnosed with colon cancer eventually develop cancer in other parts of the body. These are known as metastases. The liver, lungs, abdominal cavity or distant lymph nodes are the most common locations for colon cancer to metastasize.
Stage 4 colon cancer typically requires complex treatment strategies to manage symptoms and improve quality of life. Treatment for stage 4 colon cancer may include chemotherapy, surgery, targeted therapy, immunotherapy or radiation.
الأعراض
Colon cancer doesn't always cause symptoms, even if it's progressed to stage 4. When symptoms do happen in metastatic colon cancer, they can be similar to colon cancer that hasn't yet spread outside the colon. General symptoms may include:
- Feeling full soon after eating.
- A lump in the belly button area.
- A change in bowel habits, such as more-frequent diarrhea, constipation or changes in stool shape.
- Rectal bleeding or blood in the stool.
- Iron deficiency anemia, which can cause tiredness, weakness and a change in skin color.
- Ongoing discomfort in the belly area, such as cramps, gas, bloating or pain.
- A feeling that the bowel doesn't empty all the way during a bowel movement.
- Pain in the back, buttocks or legs.
In stage 4 colon cancer, other symptoms may happen, depending on where the cancer has spread. The most common sites of metastatic colon cancer are the liver, lungs, abdominal cavity and lymph nodes.
Symptoms of stage 4 colon cancer that has spread to the liver include:
- Pain in the upper right part of the belly.
- Loss of appetite.
- Losing weight without trying.
- A bloated, distended belly, called ascites.
- Yellowing of the skin and whites of the eyes, called jaundice.
- Itchy skin.
Symptoms of stage 4 colon cancer that has spread to the lungs include:
- An ongoing cough.
- Shortness of breath.
- Coughing up blood.
Symptoms of stage 4 colon cancer that has spread to distant lymph nodes include:
- Swollen lymph nodes above the collarbone or in the groin area.
When to see a doctor
Make an appointment with a doctor or other healthcare professional if you have any symptoms that worry you. If you've been treated for colon cancer in the past, tell your healthcare professional.
الأسباب
It's not clear what causes colon cancer to metastasize and progress to stage 4. This advanced form of colon cancer happens when cancer cells break away from where they started in the colon. The cancer cells can travel through the lymphatic system or the bloodstream to other areas of the body. Colon cancer cells also may spread by growing into nearby tissue or traveling to the lining of the abdominal cavity, called the peritoneum.
Cancer that spreads from its original location is known by the name of the primary cancer. For example, cancer that has spread from the colon to the liver is called metastatic colon cancer, not liver cancer.
Colon cancer most often spreads to the:
- Liver.
- Lungs.
- Abdominal cavity lining, called the peritoneum.
- Distant lymph nodes.
Less commonly, colon cancer spreads to the:
عوامل الخطورة
Factors that raise the risk of metastatic colon cancer are the same for colon cancer in general. These include being older than age 45, lifestyle factors, genetic traits and certain conditions, such as inflammatory bowel disease, Lynch syndrome or familial adenomatous polyposis.
While these factors increase the likelihood of colon cancer, they don't guarantee it will progress to metastatic disease. Additional factors that increase the risk of advancement to stage 4 include:
- Late diagnosis. When colon cancer isn't caught early, it can grow and spread to other parts of the body. This often happens because younger people may have unusual symptoms that don't seem serious, or their symptoms are mistaken for harmless issues like stomach upset or hemorrhoids.
- Lack of screening. If people don't get screened regularly or at all, healthcare professionals might miss growths in the colon that could turn into cancer or cancer could be caught too late. This makes it more likely for cancer to progress.
- Aggressive types of cancer. Some types of colon cancer, such as those with specific genetic changes, grow quickly and are more likely to spread to other parts of the body.
While these factors increase the risk of stage 4 colon cancer, it's possible to slow down progression. Early intervention can improve outcomes.
المضاعفات
Stage 4 colon cancer, also known as metastatic colon cancer, is linked to a range of serious complications. This is due to both the primary cancer that started in the colon and the spread of cancer to distant organs. Complications may include:
- Bowel obstruction. Cancer may grow large enough to block the colon. This can cause belly pain, bloating and nausea.
- A tear in the colon, called a perforation. A perforation is a dangerous complication that can lead to contamination and infection in the abdominal cavity. It often needs emergency surgery.
- Bleeding. Cancer may cause either slow, ongoing bleeding that leads to anemia or, less commonly, life-threatening hemorrhage.
- Liver dysfunction or failure. The liver is the most common site for colon cancer spread. Cancer in the liver can lead to liver dysfunction or failure. Signs of liver problems include belly swelling, confusion, and yellowing of the skin and eyes, called jaundice.
- Lung complications. Cancer that spreads to the lungs can cause coughing, shortness of breath or fluid around the lungs, called pleural effusion.