Blood in stools
Visible blood, or stools that appear dark — always warrants investigation.
Cancers We Treat
Colorectal cancer is Singapore's
Colorectal cancer is Singapore's
most common — and screenable.
Colorectal cancer is the most common cancer in Singaporean men and the second most common in women — yet it typically develops slowly from screen-detectable polyps. AARO provides the radiation component of colorectal care: chemoradiation for rectal cancer, and SBRT for liver and lung oligometastases.
1 in 6Male cancer patients in Singapore
2ndMost common cancer in Singaporean women
YearsFor polyps to become cancer — screening works
Image · placeholderAn AARO care coordinator explaining the treatment pathway in the patient lounge.
Image · placeholderAnatomy illustration — the colon and rectum
Colorectal Cancer · What is it
From polyp to cancer, over years.
Colorectal cancer is the uncontrolled growth of cells in the colon or rectum. Most begin as polyps — growths on the inner lining of the large intestine. Adenomatous polyps (adenomas) can transform into cancer over many years, which is exactly why screening and polyp removal prevent cancer, not just detect it.
The great majority of colorectal cancers are adenocarcinomas, beginning in the mucus-producing cells of the intestinal lining. Rarer types include carcinoid tumours, gastrointestinal stromal tumours, lymphomas and sarcomas.
If a polyp becomes cancerous, the cancer invades through the layers of the bowel wall over time. Once it reaches blood or lymph vessels, it can travel to nearby lymph nodes or to other organs — most commonly the liver and lungs, where modern SBRT gives radiation a new curative-intent role.
Colorectal Cancer · Symptoms
When to see a doctor.
Early colorectal cancer often causes few or no symptoms — which is why screening from age 50 matters. Later, these signs may appear:
Change in bowel habits
Diarrhoea, constipation, or a change in stool consistency that persists.
Abdominal discomfort
Persistent abdominal pain, cramping or discomfort.
Anaemia & fatigue
Unexplained anaemia, weakness or fatigue — often from slow, unseen blood loss.
A lump in the abdomen
A mass you or your doctor can feel.
Unexplained weight loss
Losing weight without trying.
Colorectal Cancer · Diagnosis
How colorectal cancer is diagnosed.
Colonoscopy remains the gold standard — it finds cancer, and removes the polyps that would have become cancer.
Image · placeholderScreening consultation — discussing FIT and colonoscopy
Screening
From age 50 (earlier with family history): stool-based FIT testing, or colonoscopy as the definitive screen.
Image · placeholderEndoscopy suite — colonoscopy in progress
Colonoscopy & biopsy
Direct visualisation of the colon and rectum; suspicious lesions are biopsied and polyps removed at the same sitting.
Image · placeholderStaging CT on the review console
Imaging & staging
CT of the chest, abdomen and pelvis — plus MRI for rectal cancers — establishes local extent and any spread.
Image · placeholderPathology — molecular profile of the tumour
Molecular testing
Tumour markers (CEA) and molecular profiling guide systemic therapy decisions.
Colorectal Cancer · Risk factors
What raises your risk?
Most patients are over 50 — but risk factors below shift both risk and the age screening should start.
Age
Most colorectal cancers are diagnosed after 50 — the anchor for screening guidelines.
Family history
A blood relative with colorectal cancer, or a personal history of cancer or polyps.
Inherited syndromes
Familial adenomatous polyposis (FAP) and Lynch syndrome dramatically raise risk and warrant early surveillance.
Inflammatory bowel disease
Ulcerative colitis and Crohn's disease raise long-term risk.
Diet & lifestyle
Low-fibre, high-fat diets, obesity and inactivity contribute to risk.
Diabetes
Diabetes is independently associated with higher colorectal cancer risk.
Colorectal Cancer · Treatment
How AARO treats colorectal cancer.
Surgery is the backbone of colorectal treatment — with radiation playing defined, evidence-based roles before rectal surgery and against limited metastatic disease.
Chemoradiation for rectal cancer
Radiation with chemotherapy before surgery shrinks rectal tumours, improves local control and can enable sphincter-preserving surgery.
SBRT for oligometastases
Ablative radiation for limited liver or lung metastases — treating each deposit precisely, in a handful of sessions.
VMAT / IMRT
Modern intensity-modulated delivery keeps bowel and bladder dose low across every pelvic course.
Systemic therapy coordination
Chemotherapy and targeted therapy sequenced with radiation and surgery in one multidisciplinary plan.
Colorectal Cancer · Precision
Hours of planning, for one careful treatment.
Every plan at AARO goes through detailed contouring, dose simulation, and independent physics review before a single beam is delivered. We do this so the radiation hits exactly the tissue that needs it — and avoids the healthy tissue around it.
Image · placeholderTwo AARO radiation therapists at the planning console, reviewing a treatment plan together on a multi-monitor workstation.
We plan every dose.
Our medical physicists and radiation therapists collaborate on each plan — contouring tumour and organs-at-risk, simulating dose distribution, and independently checking every parameter before delivery.
Image · placeholderAn AARO team member reviewing verification imaging at the console — daily image guidance before treatment.
We verify every session.
Imaging before each fraction confirms the target's position to the millimetre — so tight margins stay safe, and healthy tissue stays out of the high-dose region.
Image · placeholderA patient comfortably positioned beneath the Elekta linear accelerator with green laser positioning lights and the signature starry ceiling above.
Colorectal Cancer · What to expect
Quiet, precise, uneventful.
Each treatment session takes 15–30 minutes. You'll lie on a precision treatment couch beneath the linear accelerator. Positioning lasers and daily imaging align you to within a millimetre of the planned position.
You won't feel the radiation as it's delivered. There's no anaesthesia, no recovery time, and no overnight stay. Most patients drive themselves home after the session and return to normal activities the same day.
Image · placeholderThe four senior AARO specialists at the Centre for Stereotactic Radiosurgery.
Colorectal Cancer · Your specialists
Meet Dr Jonathan Teh→
Sub-specialist care.
Colorectal radiation at AARO is delivered by sub-specialists in gastrointestinal cancers and SBRT — including internationally published expertise in rectal cancer chemoradiation.
Dr Jonathan TehGU · Head & Neck · GI · Sarcoma · Paediatric
Dr David TanGynae · GI · Hepatobiliary · Lung
Recently diagnosed? Or seeking a second opinion?
Book a 45–60 minute specialist consultation. We'll review your imaging and pathology, explain the options that apply to your case, and answer your questions.