The standard treatment for locally advanced rectal cancer has been chemotherapy and radiotherapy first (the neoadjuvant part), followed by surgery to remove the affected section of bowel and the surrounding lymph nodes. Surgery is what historically gave the best chance of long-term cure.
What has shifted over the past decade or so is the recognition that, in some patients, the chemotherapy and radiotherapy work so well that no detectable tumour remains afterwards. The tumour scar may be visible, but no actual cancer can be felt on examination, seen on MRI, or found at endoscopy. This is called a complete clinical response (often shortened to cCR).
For these patients, an alternative to immediate surgery is to defer the operation and instead enter a programme of close surveillance — frequent clinical reviews, MRI scans, endoscopies, and CT scans — with surgery offered promptly if any sign of regrowth appears. This pathway is called Watch and Wait, or sometimes non-operative management.
Watch and Wait is not "wait and see". It is an active, intensive surveillance plan, with the same goal as surgery — long-term cure — but a different starting point. The trade-off is that you avoid (or at least defer) major surgery, in exchange for committing to a more demanding follow-up schedule.
The appeal of Watch and Wait is greatest for cancers very low in the rectum — close to the muscles that control the back passage. For these tumours, the standard surgical alternative is often an abdominoperineal resection (APR) — an operation that removes the rectum and the anus together, and leaves you with a permanent colostomy (a bag on the abdomen). For some patients this is a substantial change in quality of life, even when the operation goes well.
If chemotherapy and radiotherapy can shrink such a cancer completely, Watch and Wait offers the possibility of avoiding a permanent stoma altogether — at least for as long as the cancer stays away. For people facing this decision, it is one of the most important developments in rectal cancer treatment of the past decade.
A cCR is not declared lightly. Around 8–12 weeks after the last treatment session — long enough for inflammation to settle but not so long that any regrowth has time to develop — a thorough assessment is done. To be classified as a complete clinical response, all of the following need to be consistent with no detectable tumour:
- Digital rectal examination — the position where the tumour used to be feels flat, soft, and without any palpable mass or ulcer.
- MRI of the pelvis — shows only scar tissue at the tumour bed, with no measurable residual tumour, and no involved lymph nodes.
- Flexible sigmoidoscopy or colonoscopy — direct inspection of the rectal lining shows a flat scar or "white scar", with no visible tumour, ulcer, or suspicious nodularity. Photographs are taken for comparison at later visits.
- CT scan of chest, abdomen and pelvis — shows no evidence of distant spread.
If any of these is uncertain, a near-complete response may be declared and the assessment repeated a few weeks later, or surgery may be recommended. The decision to enter Watch and Wait is made at a multidisciplinary team (MDT) meeting, and is discussed with you in detail before anything is locked in.
Surveillance is most intensive in the first two years, when the chance of regrowth is highest. A typical schedule looks like this:
A typical Watch and Wait schedule
- Years 1–2: clinical review with digital rectal examination every 3 months. MRI of the pelvis every 3–4 months. Flexible sigmoidoscopy every 3–4 months. CT chest/abdomen/pelvis every 6 months. CEA blood test at each clinic visit.
- Years 3–5: review every 6 months. MRI and endoscopy every 6 months. Annual CT.
- After year 5: review and imaging usually moves to annual, similar to standard post-bowel-cancer surveillance.
This is a heavy schedule, particularly in the early years. It is not a passive option — it asks for a real commitment to attending appointments, accepting repeated investigations, and accepting that the situation could change at any review. The trade-off is that, for the patients on whom it works, surgery is avoided altogether.
The honest reality is that not every patient on Watch and Wait stays cancer-free. The published evidence — from international registries with thousands of patients now followed long-term — suggests that around 25–30 per cent of patients have a local regrowth within 2–3 years. The majority of these regrowths are detected on surveillance MRI or endoscopy before they cause any symptoms.
When a regrowth is detected:
- The case is reviewed again at the MDT meeting.
- Imaging is updated to confirm the regrowth is local and check for any distant spread.
- In most cases, the regrowth is still operable, and salvage surgery — usually anterior resection or, for very low regrowths, abdominoperineal resection — is offered.
- The published evidence suggests that patients whose regrowth is detected promptly and treated with surgery have long-term survival outcomes similar to those who had surgery up front.
This is the central trade-off of Watch and Wait. For roughly 7 in 10 patients, surgery is avoided altogether. For the remaining 3 in 10, surgery is still needed, but it is delayed and ideally performed at an earlier-detected, more treatable point.
If you are facing this choice, here are some practical considerations to weigh with your team:
Reasons Watch and Wait may suit
- Cancer was low in the rectum, where surgery would have meant a permanent stoma.
- A clear complete clinical response on all assessments.
- You are willing and able to commit to the intensive surveillance schedule.
- You live within reasonable distance of a centre that can provide the imaging and endoscopy required.
- The lifestyle implications of surgery (stoma, bowel function changes) are a particular concern.
Reasons surgery may be preferred
- Any uncertainty on imaging or endoscopy about whether residual cancer remains.
- Surgery with sphincter preservation would already have been possible — meaning the upside of avoiding surgery is smaller.
- You would find the uncertainty of ongoing surveillance hard to live with.
- Practical barriers to attending the surveillance schedule (distance, work, support).
- A preference for "dealing with it definitively" — a reasonable preference, and one many patients share.
There is no single correct answer, and what feels right is partly clinical and partly personal. The role of the team — and of the time taken to make the decision — is to make sure you are choosing with a clear picture of both pathways.
A complete clinical response (often abbreviated cCR) means that after chemotherapy and radiotherapy for rectal cancer, no tumour can be detected by any of the assessments used — digital rectal examination, MRI of the pelvis, and direct inspection at endoscopy. It is not the same as a biopsy showing no cancer cells after surgery (that is a pathological complete response, or pCR) — a cCR is what your team can see on the assessments available without operating.
It is not a guarantee of cure. The cancer can still come back, especially in the first 2–3 years. The difference is that surgery is deferred rather than abandoned — you stay under intensive surveillance, and if there is any sign of regrowth (called a "regrowth" or "local regrowth"), surgery is then offered. In published series, around 25–30 per cent of patients on a Watch and Wait pathway have a regrowth within 2–3 years — and most of these are detected early and treated successfully with surgery.
Surveillance is intensive, particularly in the first two years. A typical schedule includes review every 3–4 months for the first 2 years, then every 6 months for years 3–5, with a combination of clinical examination, MRI of the pelvis, endoscopy of the rectum, and CT scans. The exact schedule will be agreed with you in advance and adjusted to your circumstances.
If a regrowth is detected on surveillance, the team meets again to plan management. In most cases, the regrowth is local (in the rectum itself), it is still operable, and surgery is offered — most commonly anterior resection or, for very low regrowths, abdominoperineal resection. The published evidence suggests that long-term outcomes for patients with a detected local regrowth treated promptly with surgery are similar to those who had surgery up front.
It is offered to a carefully selected group of patients with rectal cancer who have had chemotherapy and radiotherapy (often total neoadjuvant therapy) and who have a complete clinical response on all the assessments. It is most often considered for cancers low in the rectum, where the alternative is a major operation with a permanent stoma. The decision is always made at a multidisciplinary team meeting and discussed with you in detail.
It is now offered in major centres internationally and in Australia, and is included in current oncology guidelines as an option for selected patients. Surgery remains the standard treatment for most rectal cancers. Watch and Wait is not a casual "wait and see" — it is an active, intensive surveillance pathway that requires commitment to frequent reviews, scans, and endoscopies, and the option of surgery if anything changes.
- Cancer Council Australia — Clinical practice guidelines for the prevention, early detection and management of colorectal cancer (NHMRC-endorsed)
- European Society for Medical Oncology (ESMO) — Rectal cancer clinical practice guidelines
- NCCN — Clinical Practice Guidelines in Oncology: Rectal Cancer
- International Watch & Wait Database (IWWD) — international registry of patients managed non-operatively for rectal cancer
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