In pathology, grading is a measure of the cell appearance in tumors and other neoplasms. Some pathology grading systems apply only to malignant neoplasms (cancer); others apply also to benign neoplasms. The neoplastic grading is a measure of cell anaplasia (reversion of differentiation) in the sampled tumor and is based on the resemblance of the tumor to the tissue of origin.[1] Grading in cancer is distinguished from staging, which is a measure of the extent to which the cancer has spread.
_-_Fonc-02-00205-g003_(cropped).jpg)
Pathology grading systems classify the microscopic cell appearance abnormality and deviations in their rate of growth with the goal of predicting developments at tissue level (see also the 4 major histological changes in dysplasia).
Cancer is a disorder of cell life cycle alteration that leads (non-trivially) to excessive cell proliferation rates, typically longer cell lifespans and poor differentiation. The grade score (numerical: G1 up to G4) increases with the lack of cellular differentiation - it reflects how much the tumor cells differ from the cells of the normal tissue they have originated from (see 'Categories' below). Tumors may be graded on four-tier, three-tier, or two-tier scales, depending on the institution and the tumor type.
The histologic tumor grade score along with the metastatic (whole-body-level cancer-spread) staging are used to evaluate each specific cancer patient, develop their individual treatment strategy and to predict their prognosis. A cancer that is very poorly differentiated is called anaplastic.
Categories
editGrading systems are also different for many common types of cancer, though following a similar pattern with grades being increasingly malignant over a range of 1 to 4. If no specific system is used, the following general grades are most commonly used, and recommended by the American Joint Commission on Cancer and other bodies:[2]
- GX Grade cannot be assessed
- G1 Well differentiated (Low grade)
- G2 Moderately differentiated (Intermediate grade)
- G3 Poorly differentiated (High grade)
- G4 Undifferentiated (High grade)
Specific systems
editOf the many cancer-specific schemes, the Gleason system,[3] named after Donald Floyd Gleason, used to grade the adenocarcinoma cells in prostate cancer is the most famous. This system uses a grading score ranging from 2 to 10. Lower Gleason scores describe well-differentiated less aggressive tumors.
Other systems include the Bloom-Richardson grading system for breast cancer and the Fuhrman system for kidney cancer. Invasive-front grading is useful as well in oral squamous cell carcinoma.[4]
For soft-tissue sarcoma two histological grading systems are used : the National Cancer Institute (NCI) system and the French Federation of Cancer Centers Sarcoma Group (FNCLCC) system.[5][6]
Examples of grading schemes
edit| Grade 1 | Low grade | Well-differentiated |
| Grade 2 | Intermediate grade | Moderately differentiated |
| Grade 3 | High grade | Poorly differentiated |
| Grade 4 | Anaplastic | Anaplastic |
| Grade 1 | Low grade | Well-differentiated |
| Grade 2 | Intermediate grade | |
| Grade 3 | High grade | Poorly differentiated |
| Grade 1 | Low grade | Well-differentiated |
| Grade 2 | High grade | Poorly differentiated |
See also
edit- TNM staging system (Other parameters)
- Tumor kinds that have their own grading system:
- Gleason score
References
edit- ^ Abrams, Gerald. "Neoplasia II". Archived from the original on 31 October 2015. Retrieved 24 January 2012.
- ^ National Cancer Institute, "Tumor Grade", accessed 18 August, 2014
- ^ Gleason, Donald F; Mellinger George T (Feb 2002). "Prediction of prognosis for prostatic adenocarcinoma by combined histological grading and clinical staging. 1974". J. Urol. 167 (2 Pt 2). United States: 953–8, discussion 959. doi:10.1016/S0022-5347(02)80309-3. ISSN 0022-5347. PMID 11905924.
- ^ Sawair FA, Irwin CR, Gordon DJ, Leonard AG, Stephenson M, Napier SS. Invasive front grading: reliability and usefulness in the management of oral squamous cell carcinoma. J Oral Pathol Med. 2003 Jan;32(1):1-9.
- ^ Neuvill; et al. (2014). "Grading of soft tissue sarcomas: from histological to molecular assessment". Pathology. 46 (2): 113–20. doi:10.1097/PAT.0000000000000048. PMID 24378389. S2CID 13436450.
- ^ Coindre JM (2006). "Grading of soft tissue sarcomas: review and update". Arch. Pathol. Lab. Med. 130 (10): 1448–53. doi:10.5858/2006-130-1448-GOSTSR. PMID 17090186.Free full text
External links
edit- CancerWeb Archived 2002-04-30 at the Wayback Machine
- Atlas Interactif de Neuro-Oncologie