Final answer:
The missing term in the sequence from benign to metastatic cancerous cell growth is 'malignant,' which refers to a tumor capable of invading and spreading to other parts of the body.
Step-by-step explanation:
The appropriate order for cancerous cell growth would be benign → malignant → metastatic. The term malignant refers to an actual cancer, where the neoplasm, or tumor, is capable of growing uncontrollably beyond its original location, invading surrounding tissues and potentially spreading to other parts of the body through a process known as metastasis. Initially, a benign tumor is non-invasive and typically not harmful, but when it becomes malignant, it acquires the ability to damage nearby tissues and organs and finally, if the malignant cells enter the bloodstream, they can initiate new tumors in distant tissues, resulting in metastatic cancer.