Which description fits grade 3 cancer?

Grade 3 cancer is characterized by poorly differentiated cells, which means that the cancer cells appear very abnormal compared to normal cells and do not resemble the original tissue from which they came. This lack of differentiation often correlates with a more aggressive behavior, leading to a larger tumor size and increased likelihood of invasion into surrounding tissues. This is a critical factor in cancer grading as it often indicates a more advanced disease that may require more intensive treatment strategies.

In contrast, other descriptions do not accurately reflect the characteristics or implications of grade 3 cancer. For instance, a grade involving a well-defined tumor with clear margins suggests that the tumor is likely easier to treat and lower on the grade scale, typically indicating less aggressive disease. Similarly, descriptions of cancer limited to the original site imply a lower grade and less invasive characteristics, while a moderately differentiated tumor with some local spread indicates an intermediate stage rather than the high-grade nature of grade 3 cancer. Thus, the description of a poorly differentiated tumor that is large and/or invading surrounding tissue aptly captures the essence of grade 3 cancer.