What is characteristic of grade 4 cancer?

Grade 4 cancer is characterized by being undifferentiated, meaning that the cancer cells have lost the characteristics of normal cells and do not resemble the tissue from which they originated. This lack of differentiation often correlates with a more aggressive behavior and a higher likelihood of metastasis, which refers to the spread of cancer to other parts of the body.

When cancer is classified as grade 4, it indicates that the tumor presents significant abnormalities in the cells, suggesting that it is likely invasive and has already spread to other areas. This can complicate treatment as well, as higher-grade cancers are generally more resistant to conventional therapies and have a poorer prognosis compared to lower-grade cancers.

The other options describe characteristics that do not align with grade 4 cancer. For instance, poorly differentiated and localized cancers would not be classified at grade 4, and well-differentiated tumors are usually easier to treat, which contrasts with the characteristics of grade 4. Additionally, the statement about showing no signs of invasion is inaccurate, as grade 4 cancers are typically associated with a significant likelihood of invasion and metastasis.