Our expert explains the stages of colon cancer, approach to cancer treatment and the survival chances of the cancer patient.
Once diagnosed with colon cancer, the next steps is to determine the stage of cancer, which indicates how far the cancerous cells have spread to decide the right treatment approach. Dr Kenneth D’ Cruz, Senior Consultant – Gastrointestinal and HBP Surgical Oncology, Cytecare Hospitals, explains about the four stages of cancer, treatment approach and the survival chances of a person with colon cancer.
Stages of cancer: There are four key stages of colon cancer, which are further classified based on the structure of the colon and how far the cells have migrated from the colon to other parts of the body.
This is the early stage of colon cancer, which indicates that the cancer is confined inside the colon. In this stage, the cancerous cells grown into the layers of the colon, known as mucosa and submucosa.
In stage 2, the cells start to move out of the colon and migrate to other areas within the colon. It is further classified into 2A, 2B and 2C, based on how far the cancerous cells have spread. In stage 2A, the cells usually reach the outer layers of the colon, whereas, in stage 2B, the cancerous cells spread past the outer layer of the colon to membranes that hold the abdominal organs. In stage 2C, the cancer might have moved to the nearby organs or structures.
In this stage, the cancerous cells spread to the nearby lymph nodes. It is further classified into 3A, 3B and 3 C based on how many lymph nodes have been affected by cancer. Stage 3A is when the lymph node close to the colon is affected. If 2 – 3 lymph nodes are affected, then it is 3B and if it’s more than 4 or distant lymph nodes are affected, then it is classified as 3C.
The final stage of colon cancer, in this stage the cancerous cells spread to other organs of the body. This is the stage when the cells have metastasized to nearby organs like the liver or the lungs. When a nearby organ is affected, it is classified as 4A, and if the cancerous cells have migrated to one or more distant organs it is classified as stage 4B.
The treatment approach is decided based on the stage of the colon cancer. Usually, stage 1 – stage 3 colon cancer can be treated with surgery, where the tumour is surgically removed (including nearby tissues and cells based on the stage of the cancer). However, if it is late stage 3 (either 3B or 3C), then you might require chemotherapy along with surgery to prevent the cancerous cells from attacking other organs fo the body. For stage 4 of the colon cancer, chemotherapy or targetted therapy is the effective mode of treatment for the cancer.
Just like the treatment, the chances of survival for people with colon cancer is dependent on the stage of the colon cancer, grade, age and overall health of the person. Grading of cancer is nothing but determining how healthy the cells look under the microscope. The higher the grade, the more abnormal the cells look and lower the prognosis. Whereas, low-grade cancer grows slowly and has a better prognosis. In general, the chances of survival is 50% for every patient for 5 years. However, depending upon the stages, it varies. For a person with stage 1 colon cancer, the survival chances are 90% for 5 years; stage 2 is 80 – 83%, stage 3 is 60%, and stage 4 is 11% for 5 years. Hence, the chances of survival decrease from stage 1 to stage 4 of colon cancer.