What is colon cancer?
Colon cancer is a malignant tumour arising from the cells lining the large bowel. In approximately 95% of cases it is adenocarcinoma. It usually develops slowly over 10–15 years from precancerous lesions (adenomatous polyps) on the bowel mucosa.
Early diagnosis through screening (colonoscopy) and radical surgery, when applied with modern oncological principles (CME — Complete Mesocolic Excision), offer excellent survival rates and good quality of life.
How common is it?
Colorectal cancer is the third most common malignancy worldwide and the second cause of cancer-related death. In Greece, approximately 7,000 new cases are diagnosed annually. Lifetime risk is approximately 5% for the general population.
Frequency increases with age — 90% of cases appear after the age of 50. With organised screening (colonoscopy from age 45–50), mortality from the disease can be reduced by 40–60%.
How does it present?
Symptoms of colon cancer often appear late and depend on the location of the tumour:
- Change in bowel habits (alternating constipation and diarrhea, change in stool calibre).
- Rectal bleeding or dark stools (melena) — small amounts may be missed.
- Abdominal pain, often colicky.
- Unexplained weight loss.
- Iron deficiency anemia (often the only sign in right-sided tumours).
- Fatigue, weakness.
- In advanced disease: bowel obstruction, perforation, palpable abdominal mass.
How is it diagnosed?
Diagnosis is based on clinical suspicion, endoscopy and staging investigations:
- Colonoscopy with biopsies — the gold standard. Allows visualisation of the entire colon and biopsy of suspicious lesions.
- Histopathology of the biopsy — confirms diagnosis and characterises the type of tumour.
- Abdominal-pelvic and chest CT — staging investigation for evaluation of local extension and metastases.
- MRI in specific cases (synchronous liver lesions).
- PET-CT in complex cases or for restaging.
- Tumour markers CEA and CA 19-9 — for postoperative follow-up.
- Mutation analysis (KRAS, NRAS, BRAF, MSI/MMR) — guides postoperative therapy.
Which factors increase risk?
About 25% of cases of colon cancer have a hereditary component. Identified hereditary syndromes (Lynch syndrome, FAP) account for 5–10% of cases.
- Family history of colorectal cancer (especially in 1st-degree relatives).
- Hereditary syndromes (Lynch syndrome — HNPCC, FAP, MAP).
- Personal history of colorectal polyps or cancer.
- Inflammatory bowel disease (Crohn's, ulcerative colitis) of long duration.
- Age >50 years.
- Obesity, sedentary lifestyle.
- Diet rich in red and processed meat, low in fibre.
- Smoking, alcohol consumption.
- Diabetes mellitus type 2.
Modern therapeutic options
The choice of the appropriate surgical technique is individualised for each patient, based on tumour location, stage of disease, comorbidities and patient preference. Treatment is multidisciplinary in the context of an oncology council.
Laparoscopic Colectomy
International gold standard for early- to mid-stage colon cancer. Performed through 4–5 small incisions with extraction of the specimen through a small auxiliary incision. Applies all oncological principles (CME) with reduced postoperative pain, faster recovery and equivalent oncological outcomes to open surgery.
Robotic Colectomy
Cutting-edge technique with excellent oncological outcomes. The Da Vinci system provides three-dimensional visualisation and articulated instruments, especially helpful for complex anatomy, total mesocolic excision (CME) and patients with high BMI.
Open Colectomy
Reserved for complex cases (very large tumours, locally advanced, severe adhesions from prior operations). Despite being the traditional approach, it remains an excellent option in selected patients with equivalent oncological outcomes.
Frequently asked questions
Will I need a colostomy?
For most colon cancers (right or left), a permanent colostomy is NOT required. Bowel anastomosis is performed during the same operation. A temporary colostomy may sometimes be required (mainly for rectal cancer), which is reversed 2–3 months later.
Will I need chemotherapy after surgery?
Depends on the final stage. In stage I no chemotherapy is needed. In stage II it is selectively considered. In stage III adjuvant chemotherapy for 3–6 months is standard. In stage IV the approach is individualised.
When should I start screening?
Screening colonoscopy is recommended from age 45. For people with positive family history, screening starts 10 years earlier than the youngest case in the family. For hereditary syndromes, screening can start from adolescence.
Will I be able to live a normal life after the operation?
Yes. After a recovery period of 4–6 weeks, the vast majority of patients return to a fully normal life with no dietary or activity restrictions. Long-term follow-up is necessary with colonoscopies and tumour markers.