Key Takeaways
- Early detection saves lives: Colorectal cancer is highly treatable when caught early, making regular screening essential—even before symptoms appear.
- Lifestyle and genetics both matter: While some risk factors can’t be changed, healthy diet choices, physical activity, and avoiding smoking and excess alcohol can lower risk.
- Treatment options are advancing: Surgery, chemotherapy, targeted therapy, and immunotherapy have significantly improved survival rates.
- Clinical trials offer hope: Ongoing research and investigational treatments are expanding options and improving outcomes for people with colorectal cancer.
Colorectal cancer is one of the most common cancers worldwide, yet it is also one of the most preventable and treatable cancers when detected early. Many people ignore early symptoms or delay screening because the disease often develops silently.
This blog explains what colorectal cancer is, how it develops, early warning signs, causes, risk factors, diagnosis, treatment options, life expectancy, and how modern clinical research is improving outcomes.
What Is Colorectal Cancer?
Colorectal cancer is a type of cancer that starts in the colon (large intestine) or the rectum, which together forms the lower part of the digestive system. Most CRC cases begin as small growths called polyps on the inner lining of the colon or rectum. While many polyps are harmless, some can slowly turn into cancer over time, often taking 10–15 years to become malignant.
This long development period is why screening saves lives. CRC can often be stopped before cancer even forms.
What Are the First Signs of Colon Cancer?
One of the most dangerous aspects of CRC is that early stages often cause no symptoms. When symptoms do appear, they are often mistaken for common digestive problems. As the disease progresses, common warning signs include:
- Changes in bowel habits (diarrhea or constipation lasting more than a few weeks)
- Persistent abdominal discomfort (cramps, gas, pain)
- A feeling that the bowel doesn’t empty completely
- Blood in the stool (bright red or dark)
- Unexplained fatigue or weakness
- Narrow or pencil-thin stools
- Unintended weight loss
These symptoms do not always mean cancer, but they should never be ignored. As CRC advances, symptoms may become more severe and include:
- Vomiting
- Intestinal blockage
- Chronic anemia due to blood loss
- Severe abdominal pain or bloating
- Shortness of breath (if cancer spreads)
Causes of Colorectal Cancer
Colon cancer develops when genetic changes (mutations) cause healthy cells in the colon to become abnormal. These altered cells begin to grow and divide uncontrollably, forming colon polyps. While many polyps are harmless, some can gradually turn into cancer.
Over time, cancer cells can grow deeper into the layers of the colon wall. If left untreated, the cancer may break through the colon wall and spread to nearby tissues or other parts of the body.
Doctors do not yet know the exact reason why these genetic changes occur. However, research has identified several factors that increase the risk of developing colon cancer. Common Risk Factors Include:
Age Over 50
Most people diagnosed with colon cancer are older than 50. However, cases in younger adults are increasing, and researchers are still investigating why this is happening.
Family History of Colon Cancer
Your risk is higher if close biological relatives—such as parents, siblings, or children—have had colorectal cancer or large colon polyps, especially if they were diagnosed before age 45.
Multiple Colon Polyps
Having many polyps in the colon increases the likelihood that one or more may become cancerous over time.
Inherited Genetic Conditions
Certain inherited disorders, such as Lynch syndrome or familial adenomatous polyposis (FAP), significantly raise the risk of developing colon cancer.
Overweight or Obesity
Studies show that having a body mass index (BMI) over 25 is associated with a higher risk of colon cancer.
Smoking
Research has found that cigarette smoking increases the risk of colon cancer by exposing the body to cancer-causing chemicals.
Regular Alcohol Consumption
Even light to moderate alcohol intake has been linked to an increased risk of colon cancer.
Prevalence of Colorectal Cancer
Colorectal cancer is a major global health concern. According to World Health Organization and Centers for Disease Control and Prevention:
- CRC is among the top three most diagnosed cancers worldwide
- Rates are rising in younger adults, likely due to lifestyle changes
- It affects men and women almost equally
- Most cases occur after age 45
Colorectal Cancer Diagnosis
A healthcare provider will begin by asking about the symptoms, what they feel like, when they start, and whether they have changed over time. They may perform a physical exam by gently feeling your abdomen, checking for lumps, swelling, or organs that seem larger than normal. In some cases, they may also perform a digital rectal exam to check the lower part of the rectum.
To confirm a diagnosis and understand how advanced the disease may be, healthcare providers may recommend several tests:
Blood Tests
These may include a complete blood count (CBC) to check for anemia, a comprehensive metabolic panel (CMP) to assess organ function, or a CEA test, which measures a tumor marker sometimes elevated in colon cancer.
Imaging Tests
Imaging helps doctors see inside the body and look for tumors or the spread of cancer. Common tests include computed tomography (CT) scans, magnetic resonance imaging (MRI), positron emission tomography (PET) scans, and abdominal ultrasound.
Diagnostic Colonoscopy
If symptoms or test results suggest cancer, a gastroenterologist may perform a colonoscopy to examine the inside of the colon. During this procedure, they remove a small tissue sample (biopsy). A medical pathologist then examines the tissue under a microscope to confirm whether cancer cells are present.
Stages of Colorectal Cancer
Diagnostic tests also help determine the cancer stage, which describes how advanced the disease is. Staging is based on factors such as where the tumor is located, whether cancer has spread to nearby lymph nodes, and whether it has traveled to other organs.
CRC is staged from Stage 0 to Stage IV:
- Stage 0: Cancer is limited to the inner lining
- Stage I: Cancer has grown into the colon wall
- Stage II: Cancer has spread through the wall
- Stage III: Cancer has reached nearby lymph nodes
- Stage IV: Cancer has spread to distant organs (liver, lungs)
Treatment of Colorectal Cancer
Surgery is the most common treatment for colon cancer that has not spread beyond the colon. The type of surgery depends on how large the tumor is and where it is located. Common surgical procedures Include:
- Polypectomy: This procedure removes precancerous or cancerous polyps from the colon, often during a colonoscopy. It is typically used for very early-stage cancer.
- Colectomy: In this surgery, the surgeon removes the part of the colon that contains cancer, along with nearby tissue and lymph nodes if needed.
In some cases, additional treatments may be recommended before or after surgery to reduce the risk of recurrence. These may include chemotherapy, radiation therapy, or targeted therapy, depending on the stage and characteristics of the cancer.
Colorectal Cancer Clinical Trials
Clinical trials play a critical role in advancing colorectal cancer (CRC) care by evaluating investigational treatments that may improve outcomes beyond standard therapy. These studies test new personalized targeted drugs designed to match specific genetic features of a tumor.
By participating in colorectal cancer clinical trials, patients may gain access to cutting-edge investigational treatments before they become widely available, while also contributing to research that helps shape the future of colorectal cancer treatment.
Hightower Clinical is actively conducting colorectal cancer clinical trials aimed at improving treatment options and patient outcomes. Participation is voluntary, and patient safety is always the top priority.
Conclusion
Colorectal cancer is a serious but highly treatable disease, especially when detected early. Understanding its causes, symptoms, and treatment options empowers individuals to take timely action, follow recommended screenings, and make healthier lifestyle choices. With ongoing advances in medical research and clinical trials, treatment options for colorectal cancer continue to improve, offering hope, better outcomes, and a stronger future for patients and their families.
Frequently Asked Questions
What is the life expectancy of someone with colorectal cancer?
It depends on the stage of diagnosis. Early-stage CRC has a 5-year survival rate of around 90%, while advanced-stage disease has lower survival rates.
How can I avoid colorectal cancer?
Maintain a healthy diet, exercise regularly, avoid smoking and excessive alcohol, and follow recommended screening guidelines.
Can colon cancer be completely cured?
Yes, especially when detected early, through surgery and appropriate treatments.
What is the root cause of colorectal cancer?
CRC develops when genetic mutations cause normal colon cells to grow uncontrollably, sometimes influenced by lifestyle or inherited factors.
