Do they find the primary cancer location all the time?

Posted by mary g @maryg, Feb 19 10:23pm

Do they find the primary cancer location all the time and what id they dont'

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According to this article by National Cancer Institute, sometime cancer of an unknown source,
Carcinoma of Unknown Primary, cannot be identified because:

• The primary cancer is very small and grows slowly.
• The body’s immune system killed the primary cancer.
• The primary cancer was removed during surgery for another condition and doctors didn’t know cancer had formed. For example, a uterus with cancer may be removed during a hysterectomy to treat a serious infection.


Article also has info on test and treatment of Carcinoma of Unknown Primary.



My cancer, which is anal, squamous cell. First showed up as a ureter cancer. When I developed the anal tumor 2 years later, it became apparent that it is my primary cancer, & the ureter cancer was from an adjacent lymph node. This is called an occult tumor (or unknown primary). I was treated with the UTUC protocol (chemotherapy & radiation). Then the anal ca protocol (different chemotherapy, & radiation).


Hi @maryg, like @roch and @amyb5 shared, the origin of the primary cancer isn't always found. This is referred to as cancer with unknown primary. You can connect with other members who have a cancer with unknown primary in this discussion:

- Anyone have cancer with unknown primary?

You also asked, what happens if they don't find the origin. Because cancer was found in the body, it is often treated with a systemic treatment like chemotherapy, targeted therapy or immunotherapy to affect cancer cells throughout the body. To help determine which type of systemic therapy will be most effective, the cancer cells will be examined for their molecular structure to see what type of cancer cells they most mimic.

It can be unsettling to get a diagnosis of cancer with an unknown origin. Have you recently received this diagnosis, Mary?

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