What is the anatomical explanation for cancerous cells being found in that region of the body?

Q1
Describe the pathway of the heart’s conduction system and how it relates to the conduction cycle.
Q2
A patient with a malignant cancer of the descending (left-sided) colon and right arm presents to their primary care practitioner with an enlarged lymph node above the right and left clavicles. A biopsy of both lymph nodes detected the presence of metastatic cells. What is the anatomical explanation for cancerous cells being found in that region of the body?