How effective is genomic tumour profiling for cancer of unknown primary?

Cancer of unknown primary means cancer has been found but its starting site remains unclear after clinical assessment and pathology. Profiling examines molecular features in tumour tissue. It may suggest a tissue of origin, reveal a change that has a potential treatment match, or show features that help the team understand the disease.

The report is interpreted alongside scans, biopsy findings, examination and laboratory results. A predicted tissue of origin is not the same as proof, and a target does not guarantee benefit. Some tumours have no finding that can be acted on with an available treatment.

Ask whether the tissue sample is sufficient and whether the test is being used to seek a tissue-of-origin clue, a treatment target, or both. Ask the oncology team to rank findings by confidence and explain how each could alter treatment.

Discuss standard treatment, targeted options and trial referrals together. Keep the molecular report for future consultations. If the cancer changes, ask whether a new biopsy is appropriate, since the profile from an earlier sample may not capture the current biology.

Speak with the oncology team when the report is available or when a proposed treatment depends on it. Seek urgent assessment for sudden breathlessness, severe pain, new weakness or confusion, or fever during treatment; profiling is planned testing rather than emergency care.

Ask whether the result suggests a likely origin, which findings are actionable, how strong the treatment evidence is, and what happens if no match is found. Ask whether a second pathology review or fresh tissue would clarify the plan.