Info
Tumor grade (G1–G4)
A classification that shows how different the cancer cells are from normal cells. G1 = slow growth; G4 = fast growth.
What it means
A histological classification that shows how different the cancer cell is from the normal cell it came from. G1 means cells that are almost normal (less aggressive), while G4 means cells that are very different (very aggressive). It helps assess how fast the tumor is growing.
In short
A classification that shows how different the cancer cells are from normal cells. G1 = slow growth; G4 = fast growth.
Where you will see it
Mentioned in the histopathology report. Recorded as G1–G4 or as well/moderately/poorly differentiated.
What it does not tell you on its own
Tumor grade on its own does not decide the treatment or predict the individual outcome. It is interpreted together with the TNM stage and other factors.
Questions for your doctor
- What tumor grade do I have?
- Does the grade affect the treatment decision?
- Does it mean the tumor is growing fast or slowly?
- Are additional molecular tests needed?
Related terms
The terms below often appear alongside this one. Each definition is right here, so you do not have to look elsewhere.
- Histopathology
- The examination under the microscope of tissue taken by biopsy or surgery. The histopathology report describes the type of cells, the tumor grade and other details that help establish the diagnosis and treatment.
- TNM (staging system)
- The international system for classifying cancer according to three dimensions: T = the size of the primary tumor, N = the involvement of the lymph nodes, M = the presence of metastases. It is the basis for stages I–IV and determines the treatment plan.
- Biopsy
- Taking a small sample of tissue or cells from the body to be examined under the microscope. It is the main method of confirming the diagnosis in oncology. The procedure is usually done under local anaesthetic and takes only a short time.
- Stage (I–IV)
- An international classification (the TNM system) that shows how far the cancer has spread: T = the primary tumor, N = lymph nodes involved, M = metastases. Stage I = localised disease, Stage IV = disease that has spread to distant sites. The stage determines the treatment plan.
Other terms in “Diagnosis”
Glossary definitions are written for patients by the OncoDots team and go through internal medical review. They explain terms; they do not establish a diagnosis and do not recommend a treatment.