Symptoms
Common signs and symptoms of Colorectal Cancer include:
When to see a doctor
If you experience severe or worsening symptoms, seek immediate medical attention. Always consult with a healthcare professional for proper diagnosis and treatment.
Causes & Risk Factors
Several factors can contribute to Colorectal Cancer.
Colorectal cancer develops when healthy cells in the colon or rectum acquire genetic mutations that cause them to grow and divide uncontrollably.
Colorectal cancer develops when healthy cells in the colon or rectum acquire genetic mutations that cause them to grow and divide uncontrollably. Think of these cells like a factory assembly line that has lost its quality control system. Normal cells follow strict rules about when to grow, when to stop, and when to die. Cancer cells ignore these rules entirely.
Most colorectal cancers begin as adenomatous polyps, small growths that form on the inner lining of the colon or rectum.
Most colorectal cancers begin as adenomatous polyps, small growths that form on the inner lining of the colon or rectum. Picture these polyps as small mushrooms growing from the intestinal wall. While most polyps remain benign throughout a person's lifetime, some accumulate additional genetic changes over 5 to 10 years and transform into cancer. This slow progression explains why regular screening can be so effective at prevention.
The exact triggers for these initial genetic changes remain somewhat mysterious, but researchers have identified several contributing factors.
The exact triggers for these initial genetic changes remain somewhat mysterious, but researchers have identified several contributing factors. Age plays the biggest role, as our cells naturally accumulate DNA damage over time. Environmental factors like diet, lifestyle choices, and exposure to certain chemicals can accelerate this process. Some people inherit genetic mutations that make them more susceptible to developing colorectal cancer, though hereditary forms account for only about 5 to 10 percent of all cases.
Risk Factors
- Age 50 or older
- Personal history of colorectal polyps or cancer
- Family history of colorectal or ovarian cancer
- Inherited genetic syndromes like Lynch syndrome
- Inflammatory bowel disease including Crohn's or ulcerative colitis
- Diet high in red and processed meats
- Sedentary lifestyle with little physical activity
- Obesity, especially excess abdominal fat
- Smoking cigarettes regularly
- Heavy alcohol consumption
- Type 2 diabetes
- Previous radiation therapy to abdomen or pelvis
Diagnosis
How healthcare professionals diagnose Colorectal Cancer:
- 1
Most people discover they have colorectal cancer in one of two ways: through routine screening when they feel fine, or after developing symptoms that prompt them to see their doctor.
Most people discover they have colorectal cancer in one of two ways: through routine screening when they feel fine, or after developing symptoms that prompt them to see their doctor. During your initial visit, your physician will ask detailed questions about your symptoms, family history, and lifestyle factors. They'll perform a physical exam that includes checking your abdomen for masses and a digital rectal exam to feel for abnormalities.
- 2
If your doctor suspects colorectal cancer, several tests can provide definitive answers.
If your doctor suspects colorectal cancer, several tests can provide definitive answers. A colonoscopy remains the gold standard, allowing doctors to examine the entire colon and rectum with a flexible tube equipped with a camera. During this procedure, they can remove polyps or take tissue samples for laboratory analysis. Other diagnostic options include CT colonography (virtual colonoscopy), flexible sigmoidoscopy, or stool-based tests that detect hidden blood or abnormal DNA.
- 3
Once cancer is confirmed, additional testing determines the extent of the disease.
Once cancer is confirmed, additional testing determines the extent of the disease. This process, called staging, typically involves:
- 4
- CT scans of the chest, abdomen, and pelvis - Blood tests including carcinoembr
- CT scans of the chest, abdomen, and pelvis - Blood tests including carcinoembryonic antigen (CEA) levels - Sometimes MRI of the pelvis for rectal cancers - Occasionally PET scans if other tests suggest widespread disease
- 5
Your medical team may also test the cancer tissue for specific genetic markers that help guide treatment decisions.
Your medical team may also test the cancer tissue for specific genetic markers that help guide treatment decisions. This molecular profiling has become increasingly important as targeted therapies continue to evolve.
Complications
- Like many cancers, colorectal cancer can cause complications both from the disease itself and from treatments.
- The cancer may grow large enough to block the intestine, causing severe abdominal pain, vomiting, and inability to pass gas or stool.
- This bowel obstruction requires immediate medical attention and often emergency surgery.
- Some tumors can also cause perforation, creating a hole in the intestinal wall that allows bacteria to spill into the abdominal cavity.
- Treatment-related complications vary depending on the specific therapies used.
- Surgery can lead to temporary or permanent changes in bowel function, and some people may need a colostomy or ileostomy (surgical openings that allow waste to exit through the abdominal wall).
- Chemotherapy can affect the immune system, making infections more likely, while also potentially causing long-term nerve damage.
- Radiation therapy may cause scarring or narrowing of the intestine months or years after treatment.
- However, most people adapt well to these changes with proper support and medical care.
Prevention
- Eat plenty of fruits, vegetables, and whole grains
- Limit red meat to no more than 3 servings per week
- Avoid processed meats like bacon, sausage, and deli meats
- Maintain a healthy weight through diet and exercise
- Exercise regularly, aiming for at least 150 minutes of moderate activity weekly
- Don't smoke, or quit if you currently smoke
- Limit alcohol to no more than 1 drink daily for women, 2 for men
Treatment for colorectal cancer depends on several factors: the stage of cancer, its location, your overall health, and your personal preferences.
Treatment for colorectal cancer depends on several factors: the stage of cancer, its location, your overall health, and your personal preferences. Surgery remains the primary treatment for most cases, especially when the cancer hasn't spread beyond the colon or rectum. For early-stage tumors, surgeons can often remove the cancer along with a margin of healthy tissue while preserving normal bowel function. More advanced cases might require removing larger sections of the colon or rectum.
Chemotherapy plays a crucial role in many treatment plans, either before surgery to shrink tumors or afterward to eliminate any remaining cancer cells.
Chemotherapy plays a crucial role in many treatment plans, either before surgery to shrink tumors or afterward to eliminate any remaining cancer cells. Modern chemotherapy regimens are much more tolerable than in the past, though they can still cause side effects like:
- Fatigue and weakness - Nausea and changes in appetite - Hair thinning or los
- Fatigue and weakness - Nausea and changes in appetite - Hair thinning or loss - Increased infection risk - Neuropathy (tingling in hands and feet)
Targeted therapy drugs have revolutionized treatment for many patients.
Targeted therapy drugs have revolutionized treatment for many patients. These medications attack specific features of cancer cells while largely sparing healthy tissue. Examples include bevacizumab, which blocks blood vessel formation in tumors, and cetuximab, which targets growth signals in certain types of colorectal cancer cells.
Radiation therapy is most commonly used for rectal cancers, often combined with chemotherapy before surgery to shrink the tumor.
Radiation therapy is most commonly used for rectal cancers, often combined with chemotherapy before surgery to shrink the tumor. For people with advanced disease, the goal shifts to controlling symptoms and maintaining quality of life for as long as possible. Promising new approaches include immunotherapy drugs that help the immune system recognize and attack cancer cells, though these work best in patients whose tumors have specific genetic characteristics.
Recent advances in personalized medicine mean doctors can now tailor treatment based on the genetic profile of both the patient and their tumor.
Recent advances in personalized medicine mean doctors can now tailor treatment based on the genetic profile of both the patient and their tumor. This precision approach is leading to better outcomes with fewer side effects for many people.
Living With Colorectal Cancer
Receiving a colorectal cancer diagnosis naturally brings a mix of emotions, from fear and anger to determination and hope. Many people find it helpful to learn as much as possible about their specific situation while building a strong support network of family, friends, and healthcare providers. Don't hesitate to ask your medical team questions, seek second opinions, or request referrals to specialists who can address specific concerns.
Latest Medical Developments
Latest medical developments are being researched.
Frequently Asked Questions
Update History
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