Importance of Cancer:
- 1,400,000 new cases of serious cancer each yr in U.S.
- 900,000 new cases of skin cancer each yr
- 560,000 deaths from cancer this yr
- 1 in 3 Americans will develop cancer
Neoplasia means new growth
Neoplasm = new growth
Tumor and neoplasm mean the same thing
Oncology = study of neoplasms
Abnormal mass of tissue, the growth of which exceeds and is uncoordinated w/ that of the normal tissues and persists in the same excessive manner after cessation of the stimuli that evoked the change
Mass is purposeless, preys on host, and is virtually autonomous
Growth of neoplasm competes w/ normal cells and tissues for energy and nutritional substrate
Autonomy is not complete; all depend on vascular supply, some depend on endocrine support
Progressive---autonomous: independent of normal growth control, and continue to grow regardless of requirements, and in the absence of any external stimuli.
Purposeless---No benefit: abnormal mass serves no useful purpose.
Parasitic---Draws benefit, but does harm: endogenous in origin but draw nourishment from the body while contributing nothing to its function.
2.Malignant = cancer
The term neoplasm does not mean cancer
All tumors have two basic components:
1. Proliferating neoplastic cells that make up their parenchyma
- The parenchymal cells represent the functional components of an organ.
- The parenchymal cells of a tumor determine its behavior and are the component for which a tumor is named.
2. Supportive stroma made up of connective tissue, blood vessels and lymph structure.
The supporting tissue carries the blood vessels and provides support for tumor survival and growth.