Why not join the Living with metastatic private group? Access group via the link here.

Primary cancer

Can someone please tell me how they know what the primary cancer is? A lady had an anx clearance and mx but they told her none of the cancer found was the primary source. How do they know? They have not yet been able to find any other cancer in her body.


  • Afraser
    Afraser Member Posts: 4,269
    That’s intriguing! According to the Cancer Council: 

    What is cancer of unknown primary?

    Cancer of unknown primary (CUP) is the term used to describe a metastatic cancer (cancer that has spread) with an unknown starting point.

    In Australia, CUP is the fifth most common cause of cancer death in men and fourth most common cause of cancer death in women.

    Usually, when cancer spreads, the secondary cancer cells look like abnormal versions of the primary cancer cells (in the tissue where the cancer began). For example, if breast cancer spreads to the lungs, the metastatic tumour in the lung is made up of cancerous breast cells (not lung cells) and is then described as metastatic breast cancer (not lung cancer).

    If it is not possible to identify the type of cancer cells the diagnosis is CUP.

  • iserbrown
    iserbrown Member Posts: 5,441
    We had a dear friend who has lost her battle. For her breast cancer was found first. Mastectomy and chemo followed.  The breast cancer was a secondary and it took some time before they found the primary. It was in the lung.
  • Afraser
    Afraser Member Posts: 4,269
    I confess I was surprised by how common (relatively speaking) CUP is. Diagnosis is always unpleasant but a secondary must be particularly hard. To know it has spread is not good, but to not know where the original cancer is must be so frustrating and frightening. Better the devil you know.....
  • primek
    primek Member Posts: 5,392
    In simple terms, primary cancer resembles closely to it's source. As it advances and spreads and mutates more it becomes impossible to tell where it came from. 
  • Blossom1961
    Blossom1961 Member Posts: 2,274
    Thank you for the info ladies. Not exactly reassuring for this lady but thank you.