Secondary cancer: what the words actually mean
Secondary, metastatic, advanced, stage 4, treatable but not curable — what each phrase means, what scan reports are saying, and what "lines of treatment" is describing.
6 min read · Part of Living With Cancer
Written by The LifeAfterward editorial team from the sources listed at the end of this page.
Not individually reviewed by a clinician. This page is written from published clinical guidance, listed in full at the end, and is general information rather than medical advice — your own team knows your case. See our editorial standards.
Last checked against its sources · Last updated · Next check due
In short
- Secondary cancer is the original cancer that has spread — breast cancer in the bones is still breast cancer, and is treated as such.
- "Treatable but not curable" is the phrase most teams use. It is not the same as untreatable, and for many cancers it now means years rather than months.
- Scan reports describe change rather than cure: response, stable disease and progression are the three words that matter.
- Treatment is usually planned as a sequence — when one option stops working, another is considered.
What this means
A great deal of distress in advanced cancer comes from vocabulary rather than from bad news. People hear "incurable" and understand "nothing can be done", or hear "stable" and cannot tell whether that is good. This page translates the words your team is using, so the conversations are about your situation rather than about what the terms mean.
The words, translated
- Secondary cancer, metastasis, "mets"
- Cancer that has spread from where it started to another part of the body. It keeps the name of the original cancer, because that is what it still behaves like and what treatment is chosen for.
- Advanced cancer
- A broad term, usually meaning cancer that has spread beyond where it started or cannot be removed by surgery. Ask your team what they mean by it in your case, because usage varies.
- Stage 4
- The staging category for cancer that has spread to distant parts of the body. It describes the extent of disease, not a timescale.
- Treatable but not curable
- Treatment aims to control the cancer and manage symptoms rather than to remove it entirely. Depending on the cancer type this can mean many years of reasonable health.
- Palliative treatment
- Treatment given to control disease and symptoms rather than to cure. Palliative chemotherapy is still active anti-cancer treatment — the word does not mean end of life. See palliative care explained.
- Line of treatment
- The order treatments are used in. First-line is what is tried first for your situation; second-line is what follows if it stops working or is not tolerated.
- Maintenance treatment
- A gentler treatment continued after an initial response, to hold the cancer where it is for as long as possible.
- Treatment break
- A planned pause, usually because the disease is stable and quality of life matters more than continuing. It is a decision, not a giving-up.
What scan results are telling you
In advanced cancer, scans are not looking for a clear result — they are measuring change against the last one. Three words carry most of the meaning.
- Response (partial or complete)
- The cancer has shrunk. Complete response means it can no longer be detected on that scan, which is not the same as cured, and treatment usually continues.
- Stable disease
- No significant change. In this setting stable is a good result — it means treatment is holding the line.
- Progression
- The cancer has grown or spread further. It usually means a change of treatment is discussed, not that treatment stops.
Scans and tests explained covers what each scan can and cannot show, and coping with waiting covers the days around them, which are hard in a particular way when scans keep coming indefinitely.
Asking about time, if you want to know
Some people want numbers. Some emphatically do not, and both are legitimate — you can also change your mind, and you can ask for a partner to be told things you would rather not hear. Say which you are; teams routinely guess wrong.
- If you do want to know, ask for a range rather than a number: "what does the best case, the typical case and the worst case look like?" It is more honest than an average and more useful for planning.
- Ask what the figures are based on, and how old they are. Treatments in advanced cancer have changed quickly, and published survival statistics often describe people treated years ago.
- Ask what would change the picture — a new treatment option, a molecular test result, a clinical trial.
- Remember that no statistic describes an individual. It describes a group of people, half of whom did better than the middle figure.
Clinical trials and molecular testing
- Ask whether molecular or genomic testing of your cancer is appropriate — it sometimes opens treatments that are not available otherwise.
- Ask whether there are trials you are eligible for, at your hospital or elsewhere. Eligibility often depends on how much treatment you have already had, which is why the question is worth asking early rather than at the end.
- Ask what a trial would involve practically: extra visits, extra scans, travel, and what happens if you want to stop.
- A trial is not a last resort, and it is not an obligation either.
What to ask your healthcare team
- In plain terms, where is the cancer now and what is the treatment trying to achieve?
- What does this scan report mean compared with the last one?
- What is the plan if this treatment stops working?
- Should my cancer have molecular or genomic testing?
- Are there clinical trials I might be eligible for?
- How much detail about the future do you think I should have — and can we agree how we discuss it?
- Who do I contact between appointments, and what should make me contact them?
Save questions to My Journey so you have them in the room, or use a ready-made list.
When to seek medical advice
With advanced cancer, some symptoms need same-day attention rather than an appointment in three weeks. Ask your team for a written list specific to your disease — the ones below are common to many situations.
Contact your healthcare team if you have:
- New or worsening pain, particularly pain that is not controlled by your usual medication.
- Increasing breathlessness, or a new cough.
- Being unable to eat or drink, persistent vomiting, or noticeable weight loss.
- New swelling in a limb, or in the face and neck.
- Confusion, drowsiness, or a change in personality that others notice.
Get emergency help the same day if you have:
- New back pain with leg weakness, numbness, or loss of bladder or bowel control — possible spinal cord compression, which needs treatment within hours.
- A temperature at or above 38°C or feeling suddenly very unwell while on treatment — possible neutropenic sepsis.
- Sudden severe breathlessness, chest pain, or coughing up blood.
- A seizure, sudden confusion, severe headache with vomiting, or new one-sided weakness.
If you are worried and unsure, contact your team anyway — they would far rather hear from you unnecessarily than late. What to do in an emergency.
Common questions
Does secondary cancer mean the treatment failed?
No. Cancer can spread despite treatment that was given correctly and worked as intended at the time, sometimes years earlier. Secondary cancer is a change in the situation, not evidence of a mistake by you or your team.
What does "treatable but not curable" mean?
That treatment aims to control the cancer and its symptoms rather than remove it completely. It is not the same as untreatable: for several cancer types it now means years of active treatment with reasonable quality of life, and the plan changes as options are used in sequence.
Is stable disease good news?
In advanced cancer, yes. It means the cancer has not grown significantly since the last scan and current treatment is holding it. Many people spend long periods with stable disease.
Sources
This page was written from the guidance below and checked against it on . Links are re-checked at each review — see our editorial standards.
- National Cancer Institute (US). Advanced cancer — coping, care and choices
- Macmillan Cancer Support. Secondary (metastatic) cancer
- ASCO (Cancer.Net). Survivorship
- European Society for Medical Oncology. ESMO patient guides
- Cancer Research UK. Coping with cancer