Stage 4 rectal cancer: what the options are
If you have been diagnosed with stage IV rectal cancer, the most important thing to know is that stage IV does not describe one single situation. The same label covers both a patient with three metastases in one lobe of the liver and a patient with disease spread through liver, lungs and peritoneum. The prognosis and the goal of treatment are completely different.
The 18% five-year survival figure that circulates for metastatic disease is the average of these very different situations. It describes nobody in particular.
Oligometastatic disease: when surgery is done with curative intent
When metastases are few and confined to one organ, particularly the liver, the situation is called oligometastatic disease, and here the objective remains cure, not palliation.
The concrete figures: after surgical resection of colorectal liver metastases, five-year survival is 40-50%. In one real-world cohort, roughly 26% of patients were free of recurrence at five years — that is, potentially cured.
More importantly, the response to chemotherapy given before surgery separates two groups sharply: five-year survival was 64% in those who responded and 15% in those who did not. Response to treatment is not merely a good sign; it is one of the strongest prognostic factors there is.
Compare 40-50% with 18% and you see why the stage IV label, taken alone, says so little.
Conversion chemotherapy
Sometimes metastases are initially too numerous or too awkwardly placed to be operated on. That does not automatically close the discussion.
Conversion chemotherapy aims to shrink metastases until they become resectable. A patient considered inoperable at diagnosis may become operable after a few months of treatment. This is why periodic imaging reassessment during chemotherapy is not a formality — it is the moment at which the whole plan can change.
There are also techniques that help make a liver operable: portal vein embolisation, two-stage hepatectomy, and radiofrequency or microwave ablation for small lesions.
What happens to the tumour in the rectum
A frequent question with no single answer.
If the rectal tumour causes symptoms — obstruction, significant bleeding, pain — it is dealt with, by surgery, a diverting stoma, a stent or radiotherapy, depending on the situation.
If the tumour causes no symptoms and metastatic disease is the dominant problem, the order changes: systemic chemotherapy often comes first, and the decision about the rectum is taken later, according to response.
In rectal cancer, unlike colon cancer, there is the additional option of pelvic radiotherapy for local control, which can spare a patient with extensive disease a major operation.
Molecular profile decides part of the treatment
This is the part that has changed most in recent years and that has to be asked for explicitly.
Before starting treatment in stage IV, the tumour should be tested for:
- RAS (KRAS, NRAS) — mutations exclude benefit from anti-EGFR therapies
- BRAF — the V600E mutation indicates a more guarded prognosis and a different strategy
- MSI / dMMR — if present, it opens the immunotherapy option, which in this setting can work dramatically
- HER2 and other targets, depending on availability
Without these results, treatment is chosen half blind. If molecular testing has not been proposed to you, ask why.
What “palliative” means — and what it does not
The word frightens people more than it should, because it is misunderstood.
Palliative treatment does not mean giving up and does not mean the final weeks. It means treatment whose goal is control of the disease and its symptoms rather than eradication. A patient on palliative treatment may live for years, work, travel.
What changes is the objective: from “let us get rid of the disease completely” to “let us keep the disease under control as long as possible, with the best quality of life”. These are two different strategies, not a good one and a bad one.
Palliative care introduced early, alongside oncological treatment, improves quality of life — it is not something done only at the end.
Why the multidisciplinary team matters more here
In stage IV, the correct decision depends on several specialties at once: medical oncologist, colorectal surgeon, liver surgeon, radiation oncologist, radiologist, pathologist.
A patient with potentially resectable liver metastases assessed only by an oncologist may remain on chemotherapy indefinitely without anyone asking the surgical question. Conversely, a patient operated on without oncological assessment may miss the optimal moment for systemic treatment.
Ask explicitly whether your case has been discussed in a multidisciplinary meeting and whether a liver surgeon has seen the images. It is one of the few questions that can concretely change the trajectory.
What to ask
- Are my metastases considered resectable, potentially resectable after chemotherapy, or unresectable?
- Has a surgeon specialising in liver surgery seen my images?
- Has molecular testing been done — RAS, BRAF, MSI?
- What is the goal of the treatment you are proposing: cure or control?
- When is imaging reassessed, and what changes if I respond well?
The honest conclusion
Stage IV rectal cancer includes situations in which cure can be achieved and situations in which it cannot. The difference is not visible from the label, but from the number and location of metastases, from the response to treatment, and from the quality of the assessment.
What you can do is make sure you have been assessed by the right people, with the right tests, before anyone decides which of the two situations is yours. General figures, including survival ones, are averages — and averages neither cure nor condemn anybody.
The information in this article is educational. Decisions in metastatic disease are made individually, by a multidisciplinary team.