What is Colorectal Cancer?
Colorectal cancer begins when a healthy cell in the lining of the colon or rectum change and begin growing out of control, forming a mass called a tumor. A tumor can either be cancerous or benign. If a cancerous tumor is malignant, it means it can grow and spread to other parts of the body, a non cancerous tumor means the tumor can grow but will not spread. These changes usually take years to develop, both genetic and environmental factors can cause the changes. However, when a person has an uncommon inherited syndrome (see Risk Factors and Prevention), changes can occur in months or years.
Types of Colorectal Cancer
It is possible for colorectal cancer to start in the colon or the rectum, colon cancer is a cancer that starts in the colon, additionally, rectal carcinoma is a type of cancer that starts in the rectus muscle.
Adenocarcinoma, a form of tumor that develops from the cells that lining the inner tissue of the colon and rectum, accounts for the majority of cases of colon and rectal cancer, adenocarcinoma is covered explicitly in this section, moreover, small cell carcinoma, lymphoma, gastrointestinal stromal tumor (GIST), and neuroendocrine tumor of the gastrointestinal tract are some other less common cancers that can start in the colon or rectum.
What is cancer staging?
A method of describing the location of the cancer, whether or not it has spread, and also whether it is impacting other sections of the body is called staging.
The stage of the cancer depends on diagnostic testing, therefore staging may not be complete until all of the tests are completed. Knowing the stage aids the doctor in recommending the best course of action and can assist in determining the prognosis, or likelihood of recovery, for a patient, additionally, for many cancer kinds, several stage descriptions exist.
TNM staging system
The TNM system is one method that doctors utilize to specify the stage. Additionally, these questions are addressed by physicians using the findings of diagnostic exams and scans:
Cancer (T): Has the tumor penetrated the colon or rectum’s wall? The number of layers?
Node (N): Have the lymph nodes been affected by the tumor? How many and where, if so?
Metastasis (M): Did the cancer spread to other parts of the body? and If so, where and how much?
To identify each person’s cancer stage, the findings are merged.
There are 5 phases: stages I through IV and stage 0 (zero) (1 through 4). The stage offers a standardized method of describing the malignancy, enabling specialists to coordinate the best course of action.
Stages of Colorectal Cancer
To determine the cancer’s stage, doctors integrate the T, N, and M data.
Stage 0:
Cancer in situ is the stage 0 condition. Only the mucosa, or inner lining, of the colon or rectum, contains cancerous cells.
Stage I:
The cancer has spread through the mucosa and into the colon’s or rectum’s muscle layer. No lymph nodes or surrounding tissue have been affected (T1 or T2, N0, M0).
Stage IIA:
The cancer has broken through the colon or rectum’s wall but has not progressed to the tissue around it or to the lymph nodes close by (T3, N0, M0).
Stage IIB:
The cancer has spread through the muscle layers to the visceral peritoneum, the lining of the belly. The lymph nodes adjacent or elsewhere have not been affected (T4a, N0, M0).
Stage IIC:
The tumor has expanded into adjacent structures and has penetrated the colon or rectum’s wall. The lymph nodes adjacent or elsewhere have not been affected (T4b, N0, M0).
Stage IIIA:
The cancer has spread into the intestine’s muscle layers or through its inner lining. It has not expanded to other body parts but has spread to one to three lymph nodes or a nodule of tumor cells in tissues surrounding the colon or rectum that do not appear to be lymph nodes (T1 or T2, N1 or N1c, M0; or T1, N2a, M0).
Stage IIIB:
The cancer has spread to nearby organs, the gut wall, one to three lymph nodes, or a tumor nodule in tissues near the colon or rectum that does not appear to be a lymph node. It has not spread to the body’s other organs (T3 or T4a, N1 or N1c, M0; T2 or T3, N2a, M0; or T1 or T2, N2b, M0).
Stage IIIC:
Regardless of how far it has progressed, colon cancer has spread to four or more lymph nodes but not to distant regions of the body (T4a, N2a, M0; T3 or T4a, N2b, M0; or T4b, N1 or N2, M0).
Stage IVA:
The cancer has only reached one far-off organ, such as the liver or lungs (any T, any N, M1a).
Stage IVB:
More than one area of the body has been affected by cancer (any T, any N, M1b).
and Stage IVC:
The peritoneum has been affected by the malignancy. It can also spread to different areas or organs (any T, any N, M1c).
Recurrent:
Cancer that has returned after therapy is referred to as recurrent cancer. The condition may affect the colon, the rectum, or another area of the body. There will be more testing to determine the amount of the cancer recurrence if it does. These examinations and scans frequently resemble those carried out at the time of the first diagnosis.
Conclusion:
The above mentioned are the stages in which colorectal cancer is categorized. Early detection and following a proper treatment plan under the guidance of an expert oncologist would aid in increasing the chances of cure and prolonging life.
