Primary cancer

Thank you for the info ladies. Not exactly reassuring for this lady but thank you. 

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. 

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.....

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.

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.