This guideline covers diagnosing and managing secondary cancers in people aged 18 and over when the site of the primary cancer is unknown. This includes people who have had treatment for cancer before. It aims to improve quality of life by offering advice on tests for identifying the site of the primary cancer and options for managing the person’s condition when this cannot be found.

This guideline covers carcinomas only and does not cover, for example, lymphoma, melanoma and sarcoma. For other NICE guidelines on cancer, see the cancer topic page.


This guideline includes recommendations on:

Who is it for?

  • Healthcare professionals
  • Commissioners and providers
  • Adults with cancer of unknown primary origin, their families and carers

Is this guideline up to date?

We checked this guideline in March 2017. We found no new evidence that affects the recommendations in this guideline.

Guideline development process

How we develop NICE guidelines

This guideline was previously called metastatic malignant disease of unknown primary origin: diagnosis and management of metastatic malignant disease of unknown primary origin.