Colon cancer is a malignant tumor that originates from the epithelial lining of the colon mucosa. It is one of the most common malignant tumors of the digestive tract, with both high incidence and mortality rates, and has shown an increasing trend in recent years. The disease most frequently occurs in the rectum and the rectosigmoid junction, followed by the cecum, ascending colon, descending colon, and transverse colon. Early detection and standardized treatment can significantly improve patient survival.
Symptoms of Colon Cancer
Early symptoms of colon cancer are often mild or non-specific. As the disease progresses, the following symptoms may gradually appear:
1. Changes in bowel habits: Diarrhea, constipation, or alternating episodes of both; increased or decreased frequency of bowel movements.
2. Abnormal stool appearance: Thinner stools, blood in the stool (bright red or dark red), mucus, or pus-bloody stool.
3. Abdominal pain and discomfort: Dull pain, bloating, or intermittent cramping, with the location of pain related to the tumor site.
4. Abdominal mass: Some patients may feel a fixed, hard lump in the abdomen, which may be the tumor itself or metastatic lymph nodes.
5. Systemic symptoms: In advanced stages, patients may experience anemia, weight loss, fatigue, low-grade fever, and cachexia.
6. Symptoms of intestinal obstruction: When the tumor blocks the intestinal lumen, symptoms such as abdominal distension, vomiting, and inability to pass stool or gas may occur, indicating acute intestinal obstruction.
Diagnosis of Colon Cancer
1. Screening Tests
Fecal occult blood test (FOBT): A simple, non-invasive initial screening method for large populations. Positive results require further examination.
Colonoscopy: The gold standard for diagnosis. It allows direct visualization of the colonic mucosa and enables biopsy for histopathological confirmation.
Imaging-based screening: Techniques such as abdominal CT, MRI, and barium enema can assist in detecting space-occupying lesions in the colon.
2. Confirmatory Tests
Pathological biopsy: Tissue samples obtained through colonoscopy or surgery are analyzed to determine the tumor type and degree of differentiation — the key basis for definitive diagnosis.
Imaging studies: Contrast-enhanced abdominal CT/MRI to evaluate the extent of tumor invasion, lymph node involvement, and distant metastases; chest CT to detect lung metastases; whole-body bone scan for bone metastases; and PET-CT for comprehensive metastasis assessment (especially in advanced or suspected metastatic cases).
Laboratory tests: Complete blood count (to assess anemia), tumor markers such as CEA and CA19-9 (to assist diagnosis, evaluate treatment efficacy, and monitor recurrence), as well as liver and kidney function tests.
Treatment of Colon Cancer
Following NCCN guidelines and clinical data from Asia, we provide individualized treatment strategies based on the stage of the disease:
90%-95%。
1. Early-stage Colon Cancer (Stage I–II): Curative Treatment with Function Preservation
Minimally invasive radical surgery: Tumor resection using laparoscopic or Da Vinci robotic techniques offers small incisions, faster recovery (patients can walk 3–5 days post-operation), and a local recurrence rate of less than 5%. For patients with fertility or sphincter-preservation needs, precise surgical planning maximizes functional preservation.
Postoperative management: Chemotherapy is not required; only regular follow-up every 6 months (colonoscopy + tumor marker tests) is needed. The 5-year survival rate can reach 90%–95%.
2. Intermediate-stage Colon Cancer (Stage III): Combined Therapy to Reduce Recurrence
Surgery + adjuvant chemotherapy: Radical resection of the tumor and lymph nodes, followed by standard chemotherapy regimens (e.g., FOLFOX, CAPOX) combined with targeted agents such as Bevacizumab to eliminate micrometastases. The 5-year survival rate increases to 50%–70%.
Neoadjuvant therapy: For locally advanced tumors, preoperative CyberKnife radiotherapy combined with chemotherapy can shrink lesions, increasing resection rates (from 70% to 85%) and reducing postoperative complications.
3. Advanced-stage Colon Cancer (Stage IV): Conversion Therapy to Prolong Survival
Targeted and immunotherapy combination: Based on molecular profiling (e.g., RAS wild-type, BRAF mutation), treatment may include anti-EGFR monoclonal antibodies or PD-1 inhibitors. Objective response rates reach 50%–60%. For patients with limited liver or lung metastases, combined surgery and ablation therapy can achieve a 5-year survival rate of 30%–40%.
Palliative care: Integrating pain management, traditional Chinese medicine, and nutritional support teams to ensure quality of life while extending survival.
Patient Cases
Mr. Lee from Malaysia (62 years old, Stage III colon cancer):
Underwent “robot-assisted surgery + postoperative adjuvant chemotherapy”. There has been no recurrence for two years after surgery, and he has now returned to normal life.
Ms. Siri from Thailand (45 years old, Stage IV colon cancer with liver metastasis):
After receiving combined targeted and immunotherapy, her metastatic lesions shrank by 80%. She then successfully underwent surgical removal of the liver metastases. She has been progression-free for 18 months under follow-up.
Common Questions About Colon Cancer
1. Who are at high risk for colon cancer?
• Middle-aged and elderly individuals over 40 years old.
• Those with a family history of colon cancer (especially when a first-degree relative was diagnosed at a young age).
• Individuals with a history of colonic polyps (especially adenomatous polyps).
• Patients with chronic colitis (such as ulcerative colitis or Crohn’s disease).
• People with long-term unhealthy lifestyles — high-fat and high-protein diets with low fiber intake, smoking, heavy alcohol consumption, obesity, or lack of exercise.
2. How can colon cancer be prevented?
• Diet modification: Increase dietary fiber intake (more vegetables, fruits, and whole grains), and reduce high-fat, fried, and processed meat consumption.
• Healthy lifestyle: Quit smoking and limit alcohol intake, exercise regularly, and maintain a healthy weight.
• Active treatment of precancerous conditions: Remove colonic polyps promptly and properly manage chronic colitis.
• Regular screening:
For individuals aged 40 and above: conduct fecal occult blood tests regularly, and undergo colonoscopy every 5–10 years.
For high-risk individuals: begin screening earlier and shorten the screening interval.
3. How should patients be followed up after colon cancer treatment?
• Within 2 years after surgery: Recheck every 3 months, including complete blood count, tumor markers (CEA, CA19-9), and abdominal ultrasound.
• Imaging: Abdominal CT/MRI every 6 months, and colonoscopy once a year.
• After 2 years: Follow up every 6 months; after 5 years, once a year for life, to detect recurrence or metastasis early.
4. What is the prognosis for colon cancer?
• Prognosis is closely related to tumor stage:
Stage I: ~90% 5-year survival rate
Stage II: ~70%–80%
Stage III: ~50%–60%
Stage IV: ~10%–20%
• Early detection and treatment are the keys to improving prognosis.
Standardized comprehensive treatment and regular postoperative follow-up can significantly reduce recurrence and prolong survival.
If you or your loved one has unfortunately been diagnosed with colon cancer, we understand the physical and emotional stress you may be experiencing, as well as the confusion and concern about treatment options.
Our oncology department adopts a multidisciplinary team (MDT) approach, bringing together specialists from gastrointestinal surgery, medical oncology, radiation oncology, imaging, and pathology to provide standardized, full-process medical services — from accurate diagnosis and personalized treatment to rehabilitation and long-term follow-up.
Based on each patient's tumor stage, physical condition, and genetic testing results, we develop an individualized treatment plan that may include surgery, chemotherapy, targeted therapy, and immunotherapy — to maximize treatment outcomes and improve quality of life.
If you would like to learn more about diagnosis and treatment details, book a specialist consultation, or seek professional medical assistance, please feel free to contact us at any time.
