Lung metastases from colorectal cancer: when surgery is an option and what the alternatives are

Can lung metastases from colon cancer be operated on?

Reviewed by: Equipo CRC Warriors (pendiente de revisión clínica) Last reviewed: 02/11/2026 Updated: 02/11/2026 4 min
In short: Yes, in selected patients. Lung metastases from colorectal cancer are often few, small and slow-growing, and when they can be completely removed a proportion of patients live for many years free of disease. Surgery (often minimally invasive), high-precision radiotherapy (SBRT) and ablation are the three tools; the decision should be made by a board that includes a thoracic surgeon.

Why the lung

After the liver, the lung is the second most common site of colorectal cancer metastases: it happens in 10-20 % of patients, and more often in rectal cancer (part of its blood drains directly into the general circulation, bypassing the liver). They often appear as small nodules, one or a few, on a follow-up CT scan, years after the primary tumour and without symptoms.

Not every lung nodule is a metastasis: nodules of a few millimetres are common in the general population (scars, old infections). That is why, when they are very small, the usual approach is to repeat the CT in 2-3 months to see whether they grow before deciding anything. A PET-CT or a biopsy help when there is doubt.

When surgery makes sense

Surgery for lung metastases (metastasectomy) is considered with curative intent when, broadly, these conditions are met:

  • The primary tumour is controlled (removed, with no local recurrence).
  • There is no disease elsewhere that cannot also be treated (an operable liver metastasis is not an obstacle: both are treated).
  • All the lesions can be removed while leaving enough lung: in practice, usually few lesions (one to three or four) and not too large.
  • Your lung function and general health allow the operation (measured with spirometry).

Factors linked to better outcomes: a single metastasis, a long interval since the primary tumour (more than 1-2 years), a normal CEA before surgery, and uninvolved mediastinal lymph nodes. None of these alone rules out surgery; they are weighed together.

How it is operated on

The most common operation is a wedge resection (the nodule is removed with a margin of healthy lung) or a segmentectomy; a lobectomy (a whole lobe) is reserved for large or central lesions. Today most are done by minimally invasive surgery (VATS or robotic), with a 2-4 day stay and recovery within a few weeks. If there are metastases in both lungs they can be operated on in two stages. The loss of breathing capacity after a wedge resection is small.

Alternatives to surgery

  • Stereotactic radiotherapy (SBRT): 3-8 high-precision sessions, with no admission or anaesthesia. It controls the treated lesion in more than 80-90 % of cases. It is the option when surgery is not possible because of lung function, age or other illnesses, or when the patient prefers it. For small, peripheral lesions the medium-term results are comparable to surgery, although they have not been directly compared in large trials.
  • Ablation (radiofrequency, microwave, cryoablation): a CT-guided needle destroys the nodule. For lesions under 2-3 cm, away from large vessels. One day in hospital.
  • Chemotherapy: before surgery (to "test" that the disease is not racing ahead and to shrink the lesions) or afterwards; its added benefit in resected lung metastases is not clearly proven, and the decision is individualised.

What the evidence says (and what it does not)

To be honest: lung metastasectomy rests on series of operated patients, with 5-year survival of 40-60 %, but there is no large trial comparing it with not operating. The only one that tried, PulMiCC, could not recruit enough patients and left the question open: part of the good outcome may be due to selecting the patients with the slowest disease. Even so, European and American guidelines recommend it in well-selected patients, because it is the only option with a chance of cure and the surgical risk is low. What matters is that the selection is made by a multidisciplinary board with a thoracic surgeon, and not decided in a single consultation.

Afterwards

Follow-up is with a CT scan every 3-6 months in the first years. New lung metastases appear in around half of those operated on; many can be treated again (a second operation, SBRT or ablation). The disease can thus become something treated in episodes, with long treatment-free periods in between.

What to ask at your appointment

  • Are we sure these are metastases, or should the CT be repeated in a few months?
  • Has my case been discussed at a board with a thoracic surgeon?
  • Surgery, SBRT or ablation: which do you recommend for me, and why?
  • Is chemotherapy needed before or after, and what is expected from it?
  • What happens if more nodules appear later: can they be treated again?

Frequently asked questions

I have a 5 mm nodule in my lung: is it a metastasis?

Not necessarily. Nodules of a few millimetres are very common and most are benign. The usual approach is to repeat the CT in 2-3 months: if it grows, it is treated as a metastasis; if it does not change, monitoring continues. Biopsying something that small is usually harder than waiting.

How many lung metastases can be operated on?

There is no fixed number; what counts is being able to remove all of them while leaving enough lung. In practice, patients with one to three or four lesions are the ones usually operated on. With more, systemic treatment is generally preferred and, if it responds well, the case is reassessed.

Is SBRT as good as surgery?

For small, peripheral lesions, control of the treated lesion is very high and medium-term results are similar, but there is no large head-to-head trial. Surgery has the advantage of confirming the diagnosis and examining the margins; SBRT, that of avoiding an operation. It is a decision to make with the board according to your case.

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Sources

This guide is general information prepared by the CRC Warriors Association (non-profit) from public medical sources. It does not replace the assessment of your oncologist or medical team, who know your case. If you spot an error, write to contacto@crcwarriors.org.