Medical Oncologist
CION Cancer Clinics
Retesting years later: when a newer genetic test is worth it | CION Cancer Clinics
If your genetic test was done some years ago and came back negative, a newer test may be worth asking about. Older tests often read only one or two genes and did not look for missing sections of genes. If your family's fault was already found, retesting rarely helps. This page explains who gains from a newer test, how the decision is made, and who does not need one. At CION Cancer Clinics in Hyderabad, our oncologists review your family history with you and guide you to the right genetic counselling and testing.
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Medically reviewed by Dr. Naresh GunduConsultant Medical Oncologist · MBBS, DNB (Internal Medicine), DM (Medical Oncology, AIIMS) · last reviewed September 2026, next review due September 2027
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On this page
- Should you be retested if your genetic test was done years ago?
- Whose old result is most worth another look?
- What happens when you ask about retesting?
- The words you will meet, in plain language
- An older test and a newer one, compared
- What this page cannot tell you
- Four things families assume, and what is actually true
- Common questions about retesting
The short answer
Should you be retested if your genetic test was done years ago?
Sometimes. If your earlier test was negative, looked at only one or two genes, or did not check for missing sections of genes, a newer test may find what the old one could not. If your earlier test already found the fault in your family, retesting rarely adds anything.
What has changed since older tests
Tests from some years back often read only BRCA1 and BRCA2, or a small handful of genes. Many did not look for deletions and duplications. Today's panels read more genes linked to cancer, usually include that copy-number check, and are interpreted with far more evidence behind them.
Three different things people call retesting
Retesting means a new test, usually on a new sample. Reanalysis means the laboratory reads your old data again with today's knowledge. Reclassification means the meaning of a variant already on your report has changed. Each answers a different question, and your counsellor will tell you which one you need.
Keep a copy of every genetic report your family has ever had, even from years ago or from abroad. It is the starting point for this decision.Who may gain
Whose old result is most worth another look?
A newer test is most useful when the old one was narrow and the family history still points strongly to an inherited cause.
Tested for BRCA1 and BRCA2 only
Several other genes are now known to raise the risk of breast, ovarian, bowel or pancreatic cancer. A family with a strong pattern and a negative BRCA result may carry a fault in one of them.
Tested before copy-number checks were routine
Older tests sometimes read only the letters of a gene. A missing or doubled section could have gone unseen. Your report's methods section usually says whether this was checked.
New diagnoses in the family since
A cousin diagnosed young, or a second cancer in a relative, can change the picture. The counsellor may now suspect a different gene from the one tested first.
Worth noting down
- Who was diagnosed since your test
- Which cancer, and roughly at what age
- Whether anyone else was tested
An uncertain result on the old report
A variant of uncertain significance usually needs reclassification, not a new test. Ask the original laboratory whether its meaning has been updated before paying for anything new.
Not sure whether this applies to you?
Ask an oncologistHow it is decided
What happens when you ask about retesting?
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The old report is read again
The counsellor checks which genes were tested, what methods were used and what was found. Without the report, this step takes longer, so bring it if you can.
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Your family tree is updated
Anyone diagnosed since the first test is added, with the type of cancer and the rough age at diagnosis, on both sides of the family.
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The gap is identified
The counsellor compares what the old test covered with what your family's pattern now suggests. Sometimes there is no real gap, and they will tell you so.
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The right person is chosen for testing
Where possible, the relative who has had cancer is tested first. If that person has died, a stored tissue block or stored DNA may still be usable.
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A newer test is arranged, if it will help
Usually a panel matched to the pattern. The new result is explained by the counsellor who ordered it, alongside what the old result did and did not show.
On your report
The words you will meet, in plain language
- Retesting
- A new test, usually on a new sample, often covering more genes than the first.
- Reanalysis
- Reading your existing data again with today's knowledge. No new sample is needed.
- Reclassification
- A change in what a variant on your report is thought to mean, as evidence builds up.
- Uninformative negative
- No fault found, but no fault was known in the family either. It lowers suspicion without settling the question.
- True negative
- You tested negative for a fault already confirmed in a relative. This is a firm answer for that fault.
- Methods section
- The part of the report that lists which genes and which kinds of change were looked for.
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Side by side
An older test and a newer one, compared
Many older tests
Most current panels
One or two genes read
Several genes matched to the family pattern
Letters read, sections often not counted
Letters read and sections counted
Less evidence to classify variants
Shared international databases to draw on
Often slower and costlier per gene
More genes read at a lower cost per gene
Being straight with you
What this page cannot tell you
It cannot tell you whether your own old test is worth repeating. That depends on exactly what it covered, how strong your family history is, and what has happened since. A genetic counsellor weighs those together, and sometimes the honest answer is that a new test would add nothing.
It cannot read an old or new result for you
Two reports from different years can use different words for the same finding. What your specific variant means is a question for the counsellor who ordered the test. Please do not compare old and new reports online and draw your own conclusions.
Who this does not apply to
If a fault was already found in your family and you tested negative for it, you do not usually need retesting for that fault. If you already carry the family fault, a new test rarely changes your care. And if your family has only one relative diagnosed at an older age, retesting is unlikely to help.
Where the evidence is still thin
How often retesting finds something new depends heavily on the family and the original test. Studies so far are mostly from outside India, so they may not reflect the genes common in Indian families.
Commonly believed
Four things families assume, and what is actually true
"We were tested once, so the question is closed."
A negative result only covers what that test looked at. If it was narrow and the family history is strong, the question may still be open.
"Everyone with an old test should repeat it."
Most do not need to. Retesting is worth it when the old test was narrow and the family pattern still looks strongly inherited. A counsellor can tell you which group you are in.
"If my uncertain result changes, the lab will phone me."
Some laboratories do contact the doctor who ordered the test, and some do not. It is reasonable to ask the laboratory, or your counsellor, to check every few years.
"A newer test will find the reason for all the cancer in our family."
It might, and it might not. Many families with a lot of cancer have no single faulty gene behind it. Screening can still be planned from the family history alone.
Questions we are asked
Common questions about retesting
How do I know if my old test was narrow?
Look at the methods section of the report. It should list the genes tested and whether deletions and duplications were checked. If only BRCA1 and BRCA2 are named, or copy-number checks are not mentioned, your counsellor will want to see it.
Can the laboratory reread my old sample instead of a new test?
Sometimes. If the laboratory still holds your DNA or your data, it may be able to reanalyse it or add genes. Many laboratories discard samples after a set period, so ask early. If nothing is stored, a fresh blood sample is used.
My relative who was tested has died. Can we still retest?
Possibly. Stored DNA from their original test, or a tissue block from an old biopsy or surgery, can sometimes be used. If neither is available, the counsellor may suggest testing a living relative who has had cancer, or a close relative of theirs.
Will my insurer or a government scheme pay for retesting?
Coverage varies. Ask your insurer directly, and ask the hospital whether Aarogyasri or Ayushman Bharat covers any part of genetic testing in your case. Many families end up paying themselves, so it helps to know exactly what the new test adds first.
My old result was uncertain. Should I retest?
Usually the first step is asking the original laboratory whether that variant has been reclassified. A new test does not change the meaning of an old variant. If the laboratory cannot be reached, your counsellor can check shared public databases.
My old test was done abroad. Does that matter?
Not in itself. What matters is what the test covered and whether you still have the report. Bring a copy in any form you have, even a photo on your phone, and the counsellor will work from it.
How often should an old result be reviewed?
There is no fixed rule. A sensible time to ask is whenever someone new in the family is diagnosed, when you are planning a major decision such as surgery, or when your counsellor suggests it. Keep your contact details up to date with the laboratory.
Where do I start if I think my old test is out of date?
Find the old report and write down who in the family has been diagnosed since. Take both to a genetic counsellor or your oncologist. Call the CION helpline if you are not sure who to approach, and we will point you to the right clinic.
Your Specialists
Meet CION's oncologists. Bring your family history or genetic report to them.
Our medical oncologists see people with a strong family history of cancer, arrange genetic counselling and testing where it fits, and plan the checks that follow.
Medical Oncologist
Dr. C. Raghavendra Reddy
MBBS(Gold Medal), DNB(General Medicine), DM(Medical Oncology)(Gold Medal)
Medical Oncologist
Dr. Bharati Devi Gorantla
MBBS, MD(General Medicine), DM(Medical Oncology)(Adyar,Chennai), ECMO, MRCP SCE(UK)
Medical Oncologist
Dr. Owais Mohammed
MBBS, MD (General Medicine), DrNB (Medical Oncology), ECMO, MRCP SCE (Medical Oncology) (UK)
Medical Oncologist
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Sources
- National Cancer Institute — Genetic Testing for Inherited Cancer Susceptibility Syndromes
- NCCN — Genetic/Familial High-Risk Assessment: Breast, Ovarian, Pancreatic, and Prostate
- MedlinePlus Genetics — What do the results of genetic tests mean?
- ClinVar (NCBI) — ClinVar: public archive of variant classifications
This page is general information, not a prescription. Do not change or stop any treatment based on what you read here. If anything is worrying you, contact your own treating team — or call our helpline and we will help you reach the right specialist.
Keep reading
Related pages
When an older negative test should be repeatedA closer look at the negative-result caseLarge genomic rearrangements and why panels can miss themOne of the main things older tests missedMultigene panel testing explainedWhat a newer test usually looks likeWhich test would your situation need?Match the test to your family's circumstances
Talk to us
Wondering whether your old test still holds?
Bring us the old report and a note of who in your family has been diagnosed since, and we will help you work out whether a newer test would add anything. One helpline serves every CION centre.