How Do I Know?

[seven7]

Two months ago I had a modified radical mastectomy on left breast, with 15 lymph nodes removed. The cancer was lobular, and was 5 cm in size. 14 positive nodes out of the 15 taken.
5 days after the surgery had chest xray, Bone scan,CT Scan.
The results of these tests are:
CHEST XRAY::    bones, heart, and mediastinum are normal.  Lungs are clear, There is no signifiant pleural abnormality. Impression.  negative chest
BONE SCAN: I.  No evidence of metastasis
           2.  Increased uptake in left foot,
            in the area that corresponds with a history of      recent trauma.
CR SCAN OF PELVIS AFTER ORAL AND IV CONTRAST: Normal CT scan of the pelvis ...normal appearance of liver, spleen, kidneys,and pancreas.  aorta was unremarkable.
----------------------------------------------------------- I am now considered clear of cancer, except for the possibility that a few stray cells are out there somewhere.  I am now taking chemo, and will have radiation, then cancer pill.
My question is, how do I know that I do not have something in my brain?  That was not tested.  I have an aunt(on my mother's side) that had cancer that went from breast to brain.Also, I had caught one of my feet in the car door sometime in the last year.  I do not even remember which foot.  So how do I know that the foot scan that showed trauma was not a cancerous spot?        Sorry for such a long letter.

[CCF-RN,MSN-JS]

Dear Seven7,  The increased uptake seen by the radiologist on the bone scan may be more indicative of injury rather than malignancy.  If a relatively recent injury to the foot has occurred and the remainder of the bone scan is normal, the clues point to the injury as being the cause of the increased uptake and not a cancerous lesion.  

As to the brain, testing of the brain for staging purposes in breast cancer is not always done, unless there are suspicious symptoms for possible metastasis (confusion, memory loss, other neurologic symptoms).