Short answer
Hereditary cancer genetic testing looks for inherited variants that can raise cancer risk. The usual question is not just whether a variant exists, but whether it changes screening, prevention, family testing, or treatment. BRCA1/2 and Lynch syndrome are common examples, but the best test depends on the person, the family history, and sometimes tumor testing first.
When testing helps
| Situation | Why testing may help |
|---|---|
| Breast, ovarian, colorectal, or endometrial cancer in the family | Family patterns can point toward a hereditary syndrome. |
| Young age at diagnosis or multiple related cancers | Earlier or clustered cancers can raise suspicion for inherited risk. |
| Known mutation in the family | Targeted testing can clarify whether relatives carry the same change. |
| Abnormal tumor testing | Tumor results may point to inherited cancer risk and need germline follow-up. |
| Pregnancy or family-planning questions | Carrier or hereditary risk decisions may affect partner testing or future planning. |
Result types
| Result | Meaning | What usually comes next |
|---|---|---|
| Pathogenic / likely pathogenic | A change linked to increased cancer risk. | Review screening, prevention, treatment, and family testing. |
| Negative | No reportable variant found in the genes tested. | Check whether family history still changes risk or screening. |
| VUS | Variant of uncertain significance. | Usually do not change care based on this alone; wait for reclassification or more evidence. |
| Tumor-only finding | A variant seen in the cancer, not yet proven inherited. | Ask whether germline testing is needed to clarify inherited risk. |
BRCA versus Lynch context
BRCA-related testing is often discussed when breast or ovarian cancer risk is the central concern. Lynch syndrome testing is often discussed when colorectal or endometrial cancer patterns are central, especially if tumor testing is abnormal. These are not the only hereditary cancer syndromes, but they are two of the clearest examples of why the test choice has to match the pattern.
NCI and CDC both stress that tumor testing can point toward a hereditary syndrome but does not by itself prove an inherited mutation. That distinction matters because tumor and germline results can lead to different family implications.
When counseling helps
Genetic counseling is especially useful when a cancer-risk result will change screening, surgery timing, or family testing. It helps turn a panel result into a concrete plan for relatives, surveillance, and the possibility of a VUS or tumor-only finding.
Questions before testing
- Should the affected relative be tested first?
- Which cancer syndrome or gene is most likely based on the family history?
- Is the test a single-gene test or a multigene panel?
- Could the result change screening, prevention, treatment, or family testing?
- Will I have access to counseling before and after the result?
FAQ
Who is hereditary cancer genetic testing for?
People with a strong family history, a personal cancer history, certain ancestry-related risk patterns, or an abnormal tumor test may be candidates.
Is BRCA testing the same as hereditary cancer testing?
No. BRCA testing is one common type of hereditary cancer testing, but other genes and syndromes can matter too, including Lynch syndrome.
Should the affected relative be tested first?
Usually yes when possible, because testing an affected relative often gives a clearer answer for the family.
What does a VUS mean?
A variant of uncertain significance is a DNA change whose cancer-risk meaning is not yet clear, so it usually should not drive major medical decisions by itself.
Do negative results rule out inherited risk?
No. A negative result can still leave family-history risk, testing-panel gaps, or variants not covered by the assay.
When is genetic counseling most useful?
Counseling is most useful when the result could change screening, surgery, medication decisions, pregnancy planning, or family testing.
Related guides: when to use a genetic counselor, FDA-authorized genetic tests, whole genome sequencing reports, and direct-to-consumer genetic testing.