# Grade Source: https://onco.cc/terms/tumour-grade/ OnCo record `tumour-grade` (Term). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence. ## TL;DR How abnormal the cancer cells look under the microscope, from grade 1 (close to normal, slow) to grade 3 or 4 (wildly abnormal, fast). Grade is about behaviour; stage is about extent. ## Summary Pathologists assign grade from how well the cells resemble their parent tissue (differentiation), how variable their nuclei are, and how many are dividing; the schemes are tumour-specific, such as the Nottingham score in breast, Gleason in prostate, and WHO grades 1 to 4 in brain tumours. High grade predicts faster growth and earlier spread but also, often, better response to chemotherapy, and grade feeds into decisions about whether to add chemotherapy after surgery. Grade should not be confused with the 'grade' of a side effect, which is a separate severity scale. ## Fields - Kind: Term - Last checked: 2026-09-09 - Also known as: tumour grade; tumor grade; grading; high-grade; low-grade; high grade; low grade; intermediate-grade; Gleason; Gleason score ## Notes - The breast scheme in full. The Nottingham grade, the Elston and Ellis revision of Bloom and Richardson, adds three scores of 1 to 3, for tubule formation, nuclear pleomorphism and mitotic count, into a total of 3 to 9: grade 1 is 3 to 5, grade 2 is 6 or 7, grade 3 is 8 or 9. UK practice permits no alternative scheme and requires the three component scores to be recorded. The grades are not expected in equal thirds: the dataset gives the ratio of grades 1, 2 and 3 as about 2:3:5 in symptomatic and 3:5:2 in screen-detected breast cancer (see `nottingham-grade`). ## Sources - Wikipedia: https://en.wikipedia.org/wiki/Grading_(tumors) - Wikipedia: https://en.wikipedia.org/wiki/Grading_(tumors) - Elston and Ellis, Histopathology 1991;19:403 to 410: pathological prognostic factors in breast cancer, the value of histological grade, with long-term follow-up of 1,831 graded patients: https://doi.org/10.1111/j.1365-2559.1991.tb00229.x - Royal College of Pathologists G148: dataset for histopathological reporting of breast disease in surgical excision specimens of breast cancer, version 3, November 2024 (full review due November 2026): https://www.rcpath.org/resourceLibrary/g148-dataset-for-histopathological-reporting-of-breast-disease-in-surgical-excision-specimens-of-breast-cancer.html ## Connected records - terms: [AJCC 8th edition prognostic stage for breast cancer](https://onco.cc/terms/ajcc-prognostic-stage-breast/), [Benign versus malignant](https://onco.cc/terms/benign-vs-malignant/), [Cell division](https://onco.cc/terms/cell-division/), [Classical versus basal-like (squamous) subtypes of pancreatic cancer, and GATA6](https://onco.cc/terms/classical-vs-basal-like/), [Depth of invasion (DOI)](https://onco.cc/terms/depth-of-invasion/), [Differentiation](https://onco.cc/terms/differentiation/), [GIST risk stratification (mitotic count, size, site; Miettinen and modified NIH criteria)](https://onco.cc/terms/gist-risk-stratification/), [Grade, stage and receptor status: three different things on one breast report](https://onco.cc/terms/grade-stage-receptor-breast/), [HERACLES criteria (HER2 in bowel cancer)](https://onco.cc/terms/heracles-criteria/), [Histology](https://onco.cc/terms/histology/), [Ki-67 in triple-negative breast cancer](https://onco.cc/terms/ki-67-in-tnbc/), [Nottingham grade (breast cancer grade 1, 2 and 3)](https://onco.cc/terms/nottingham-grade/), [Nottingham Prognostic Index (NPI), and PREDICT](https://onco.cc/terms/nottingham-prognostic-index/), [Pancreatic intraepithelial neoplasia (PanIN), the microscopic precursor of pancreatic cancer](https://onco.cc/terms/panin/), [Percentage of Gleason pattern 4](https://onco.cc/terms/percentage-gleason-pattern-4/), [Polyp types in the bowel](https://onco.cc/terms/colorectal-polyp-types/), [Prognosis](https://onco.cc/terms/prognosis/), [Proliferation](https://onco.cc/terms/proliferation/), [Stage](https://onco.cc/terms/cancer-stage/), [The subtype and grade on a cutaneous squamous cell carcinoma report](https://onco.cc/terms/cscc-subtype-and-grade/), [Toxicity grade](https://onco.cc/terms/toxicity-grade/) - cancers: [Adenoid cystic carcinoma of the breast](https://onco.cc/cancers/adenoid-cystic-carcinoma-breast/), [Adenoma-like adenocarcinoma of the colon and rectum](https://onco.cc/cancers/colorectal-adenoma-like-adenocarcinoma/), [Adenosquamous and squamous carcinoma of the gallbladder](https://onco.cc/cancers/gallbladder-adenosquamous-squamous-carcinoma/), [Adenosquamous carcinoma of the pancreas](https://onco.cc/cancers/pancreatic-adenosquamous-carcinoma/), [Breast cancer (all types)](https://onco.cc/cancers/breast-cancer/), [Colloid (mucinous non-cystic) carcinoma of the pancreas](https://onco.cc/cancers/pancreatic-colloid-carcinoma/), [Colorectal cancer](https://onco.cc/cancers/colorectal/), [Gallbladder adenocarcinoma](https://onco.cc/cancers/gallbladder-adenocarcinoma/), [Gallbladder cancer](https://onco.cc/cancers/gallbladder/), [Glioma & glioblastoma](https://onco.cc/cancers/glioblastoma/), [HR-positive / HER2-negative breast cancer](https://onco.cc/cancers/breast-hr-positive/), [Intraductal papillary mucinous neoplasm and other pancreatic cystic precursors](https://onco.cc/cancers/ipmn-cystic-precursors/), [Invasive carcinoma arising in an intraductal papillary mucinous neoplasm (IPMN-associated carcinoma)](https://onco.cc/cancers/ipmn-associated-carcinoma/), [Metaplastic breast carcinoma](https://onco.cc/cancers/metaplastic-breast-carcinoma/), [Micropapillary adenocarcinoma of the colon and rectum](https://onco.cc/cancers/colorectal-micropapillary-carcinoma/), [Mucinous cystic neoplasm of the pancreas with associated invasive carcinoma (MCN-associated carcinoma)](https://onco.cc/cancers/mcn-associated-carcinoma/), [Neuroendocrine carcinoma of the gallbladder](https://onco.cc/cancers/gallbladder-neuroendocrine-carcinoma/), [Pancreatic acinar cell carcinoma](https://onco.cc/cancers/pancreatic-acinar-cell-carcinoma/), [Pancreatic ductal adenocarcinoma](https://onco.cc/cancers/pancreatic/), [Pancreatoblastoma](https://onco.cc/cancers/pancreatoblastoma/), [Prostate cancer](https://onco.cc/cancers/prostate/), [Secretory carcinoma of the breast](https://onco.cc/cancers/secretory-carcinoma-breast/), [Solid pseudopapillary neoplasm of the pancreas](https://onco.cc/cancers/solid-pseudopapillary-neoplasm/), [Triple-negative breast cancer (TNBC)](https://onco.cc/cancers/tnbc/), [Undifferentiated carcinoma of the pancreas with osteoclast-like giant cells](https://onco.cc/cancers/pancreatic-undifferentiated-carcinoma-ogc/) --- JSON: https://onco.cc/api/v1/entities/tumour-grade.json