Final answer:
The spreading process of a primary tumor is referred to as invasion, and the process where malignant cells spread and establish a secondary tumor at a distant site is known as metastasis. Option d. Invasion; Metastasis, is the accurate answer.
Step-by-step explanation:
The spreading process of a primary tumor is called invasion, and the dispersion of malignant cells to establish a secondary tumor is called metastasis. Therefore, the correct answer to the question is option d. Invasion; Metastasis.
Cancer spreads from the original site, the primary tumor, in several ways. One way is local spread, where cancer cells aggressively invade nearby tissues. Additionally, cancer cells can spread to regional lymph nodes through the lymphatic system. The third way is through the bloodstream to distant sites, which is known as metastasis. Metastatic cancer cells establish new tumors, referred to as metastases, in other organs. This process is characteristic of malignant tumors, which are considered cancerous due to their ability to invade surrounding tissues and metastasize to distant sites within the body.