Tumor Grading for Ovarian Cancer
Tumor grade generally refers to the degree of differentiationor maturityof the cells that make up the tumor within the ovary. Worldwide there are many different systems for the grading of ovarian cancers, without a common standard.
Most investigators use criteria such as the architectural "pattern" of the cells and their nuclear content (e.g., DNA "ploidy," or how many pairs of chromosomes are present), although additional factors may be considered, such as the tumor's margin, invasion of the blood vessels, and penetration of the ovarian capsule (surface).
Most epithelial cancers are categorized by three grades of cells:
- Grade 1: the least malignant, with well-differentiated cells
- Grade 2: intermediate, with moderately differentiated cells
- Grade 3: the most malignant, with poorly differentiated cells
Overall, low-grade (e.g., Grade 1) tumors grow more slowly and have a better prognosis than high-grade tumors.