Final answer:
The most common metastasis location for both breast cancer and prostatic cancer is the bone. This is where cancer cells often form new tumors after spreading from the original site.
Step-by-step explanation:
One of the most common metastasis locations for both breast cancer and prostatic cancer is the bone. Breast cancer cells and prostatic (prostate) cancer cells often travel through the blood to distant sites, where they can form new tumors, known as metastases. Cancer cells generally have preferred sites where they grow, and the bone is a common site for these two types of cancers. The spread of cancer to the bone could lead to additional symptoms including pain and fractures, which significantly impact the prognosis and management of the disease.