NCIt definition : A general term that refers to a TNM finding of a primary tumor with direct invasion
of adjacent structures. The definition of T4a TNM finding depends on the specific
type of cancer that it refers to; for example, for bladder cancer it refers to a primary
tumor that invades the prostatic stroma, uterus, and vagina; for gastric cancer it
refers to a primary tumor that invades the serosa (visceral peritoneum); for colorectal
cancer it refers to a primary tumor that penetrates to the surface of the visceral
peritoneum.;