Direct answer
Genetic testing in cancer care may examine inherited changes present in the body’s cells or changes found mainly in the tumor. These are different questions: germline testing can affect relatives, while tumor biomarker testing may help characterize a cancer or identify treatment options.
What is germline genetic testing?
Germline testing looks for inherited variants using blood, saliva, or another normal-tissue sample. Results may affect cancer-risk management for the patient and biological relatives, so pre- and post-test counseling can be important.
What is tumor biomarker testing?
Tumor testing examines tissue or sometimes blood for molecular features of the cancer. It may help with diagnosis, prognosis, treatment selection, or clinical-trial search, but not every finding is actionable.
What details should be saved with the report?
Keep the laboratory, specimen type and date, genes or markers tested, test method, result classification, limitations, and full interpretation. Save later amended reports because classifications can change.
Which questions help interpret a result?
Ask whether the finding is inherited or tumor-only, whether confirmation is needed, what evidence supports an action, what a negative result does not rule out, and whether relatives should speak with a genetics professional.
Practical checklist
- Purpose of the test
- Specimen and laboratory
- Full report and limitations
- Result classification
- Counseling and follow-up plan
Frequently asked questions
Is tumor sequencing the same as inherited testing?
No. Tumor testing can sometimes suggest an inherited variant, but a separate germline test may be needed to confirm it.
Does a variant of uncertain significance guide treatment?
An uncertain variant generally should not be treated as a confirmed harmful inherited change; discuss the exact report with qualified professionals.
Sources
- National Cancer Institute — Genetic Testing Fact Sheet (accessed 2026-07-27)
- National Cancer Institute — Biomarker Testing for Cancer Treatment (accessed 2026-07-27)