Stages of cancer

The stage of cancer is determined by examining the cancerous tissue. There are two ways of estimating the location of a tumour, called grading and staging. When a malignant tumor is found, grading and staging also help in ensuring proper treatment. Grading is a histologic process in which tissues are examined under a microscope. While staging is the clinical process, in which the stage of cancer is detected by common diagnostic procedures. The detailed information about both these processes is as follows –

cancer grading

In this the tissue is first examined under a microscope and then the cancer is classified according to grade. Microscopic images of cancerous tissue usually reveal two things: how fast the cancer is growing and how the cancerous cells compare to healthy cells. When a large number of cancer cells have grown in a part of the body, the cancer is called “benign”. When cancer cells have spread not only in one part but also in other places, then this condition is called metastatic.

Brodar’s grading system depends on the extent of change in the cancer cells, with cancer cells having more changes. This refers to cells that appear normal and gradually proliferate to cells with minimal changes. These cells look very similar to their normal appearance. These grades are as follows –

grade 1 – completely transformed cells

grade 2 – cells with about half the change

grade 3 – cells with approximately half the change

Grade 4 – cells with low change

Diagnosis is also done with the help of pathological tests, lab tests as well as clinical examination. With the help of these tests, it is determined how far the tumor or cancer has spread.

TNM staging and the American Joint Committee (AJC) are the two main methods used to determine the stage and grade of cancer and have been used until recently.

cancer staging

tnm staging

TNM staging has three parts, in which “T” refers to the primary tumor, “N” refers to the lymph node and “M” refers to metastasis. These three components are represented by numbers, which show how much the cancer has grown or spread. The numbers of these components are as follows –

T0 – which means no tumor is found

T1-3 – Numbers 1 through 3 indicate that the tumor is growing in size. Which means, the higher the number, the bigger the tumor.

N0 – This means there is no cancer in the lymph node.

N1 to N3 – This refers to the number and size of cancer in the lymph node. Along with this, it is also known that how many lymph nodes are affected. The higher the number, the more lymph nodes are affected.

M0 – indicates that metastasis has not spread to other sites.

M1 – indicates that the tumor has spread from one site to other areas.