Second opinion in oncology: how to request it in the public health system and what to bring

How do I request a second medical opinion if I have colon cancer?

Reviewed by: Equipo CRC Warriors (pendiente de revisión clínica) Last reviewed: 01/11/2026 Updated: 01/11/2026 3 min
In short: In Spain a second opinion is a recognised right in the public health system for serious illnesses such as cancer. It is requested in writing at your hospital's Patient Services office or from your regional health department, you do not need to justify it to your oncologist, and it does not mean losing the doctor treating you. Bring copies of all your reports, the pathology and the images.

It is a right, not an insult

Asking for a second opinion is normal in oncology and good doctors understand it; many suggest it themselves. Law 41/2002 on patient autonomy recognises the right to information and to decide, and every autonomous community has regulated second opinions in the public system for serious conditions, including cancer. You do not have to justify it, your doctor is not changed and your treatment continues in the meantime.

When it makes most sense

  • At diagnosis, before deciding on complex surgery (low rectum, liver or lung metastases, peritoneal disease).
  • When you are told something is "not operable" or "there is no further treatment".
  • If your tumour has an uncommon feature (BRAF V600E, HER2, MSI-H, NTRK, young age).
  • If you want to know whether there are clinical trials you have not been offered.
  • If you do not understand or are not convinced by the plan and the relationship with your team is not helping to resolve it.

How to request it in the public system

  1. Where: at your hospital's Patient Services / User Services office (Servicio de Atención al Paciente), or from your regional health department (many have an online form). Some regions require the request within a set time from diagnosis (for example, 30 days); check yours.
  2. What: a written request stating the diagnosis and, if you wish, the preferred centre or specialist (normally it must be a public centre in the same region; some allow national reference centres, the CSUR).
  3. Timeframe: the administration usually has 15-30 days to respond and the second-opinion report is issued within weeks. If time is pressing, say so explicitly.
  4. Outcome: you receive a written report. If it agrees, it gives you peace of mind; if it differs, you can ask both teams to discuss it or choose to be treated where the alternative is offered (depending on your region's rules).

In the private sector or abroad you can request one yourself; you (or your insurer) bear the cost. It is compatible with continuing treatment in the public system.

What to bring (and what you are entitled to)

You are entitled to a full copy of your medical record; request it in writing at Patient Services. For a useful second opinion you need:

  • The pathology report (biopsy and surgical specimen) and the molecular report (RAS, BRAF, MSI, HER2, NGS panel if any). If the other centre asks, the slides or paraffin block can be lent.
  • Images (CT, MRI, PET) on CD/USB or access to your region's platform, not just the written reports.
  • Oncology, surgery and radiotherapy reports and the tumour board minutes if they exist.
  • Blood tests with CEA, and the list of treatments received with dates.
  • Your questions, written down.

How to raise it with your oncologist

It is not compulsory, but it is usually better to say so: "I would like a second opinion for peace of mind; could you prepare a summary report for me?" Most appreciate it. If the response is hostile, that is one more reason to get one.

What to ask at your appointment

  • Has my case been discussed at the tumour board, and which specialties took part?
  • What alternatives to the proposed plan exist, even if they are not done at this hospital?
  • Is there a reference centre for my situation?
  • Can you give me copies of all the reports and images?

Frequently asked questions

Will I lose my oncologist if I ask for a second opinion?

No. The second opinion is an additional report; your doctor and your treatment continue as before. You would only change centre if you decide to and your region's rules allow it in order to apply the alternative.

Can I request the second opinion in another autonomous community?

Through the public route, generally only within your own region, except for referral to a national reference centre (CSUR). Privately you can choose any centre, in Spain or abroad.

How long does it take?

It depends on the region: most set 15-30 days to assign the centre and the report usually arrives within a few weeks. If your treatment cannot wait, do not delay it for the second opinion; it can be done in parallel.

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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.