Colorectal cancer: Oncologist navigates through the stages of tumour, treatment options | Health News

In Stage 2 of colorectal cancer, the tumors don’t reach the lymph nodes but can extend to the colon or rectum wall into nearby tissues or organs. These patients need careful assessment by radiology and appropriate surgical planning.

In Stage 3C, the cancer has advanced beyond the colon or rectum wall and invaded the tissues lining abdominal organs without spreading to adjacent organs.

New Delhi: Colorectal cancer begins as a small growth called a polyp in the colon or rectum, which can turn into cancer over time if left untreated. While the exact cause of colorectal cancer is not fully understood, certain risk factors such as age, family history, smoking, and a diet high in processed food can cause this cancer. By raising awareness about the importance of early detection and adopting healthy lifestyle habits, it is possible to reduce the burden of colorectal cancer. Moreover, people should also be aware of the various stages of this cancer.

In an interaction with News9Live, Dr Ganesh Nagarajan, Director of Hepatobiliary Pancreatic Gastrointestinal Oncology, Nanavati Max Institute of Cancer Care, wrote about the stages of colorectal cancer and treatment options for patients.

What are the stages of colorectal cancer?

“Early-stage colorectal cancer or Stage 0 or carcinoma in situ, has cancer cells restricted to the innermost lining of the colon or rectum. There is the presence of abnormal cells in the innermost layer (mucosa) of the colon or rectum that have not yet developed into cancer called high grade dysplasia which may show some cancer related changes called carcinoma in situ. These can be treated in select patients by endoscopic mucosal resections,” said Dr Nagarajan.

1. Stage 1 of colorectal cancer: Here the cancerous cells are situated in the deeper layers of the colon or rectum wall without spreading to other body parts. The cancer cells are present in the innermost lining of the colon or rectum and have extended into the second layer of tissue (the submucosa) or sometimes, even to the neighboring muscle layer (muscularis propria), but not to nearby lymph nodes. These have the best outcomes with radical surgery and often can be done by robotic or laparoscopic techniques. Long term outcomes are excellent with more than 90 percent cure rates
2. In Stage 2 of colorectal cancer, the tumors don’t reach the lymph nodes but can extend to the colon or rectum wall into nearby tissues or organs. These patients need careful assessment by radiology and appropriate surgical planning. Node negative patients still have a very good prognosis if complete resection is done. Some of these rectal cancers will need chemo radiation before surgery.
3. Stage 3 of colorectal cancer: Now the cancer cells have extended to local lymph nodes but have not advanced beyond these nodes. This stage involves:
   Stage 3A: The cancer has infiltrated the initial two inner layers of the colon or rectum wall (mucosa and submucosa) and possibly reached the third layer (muscularis propria). It has also affected one to three nearby lymph nodes, or cancer cells are present close to these lymph nodes. Moreover, the cancer has penetrated through the first two layers of the colon or rectum wall and has spread to four to six nearby lymph nodes.
   During Stage 3B, the cancer has infiltrated the outer layer of the colon or rectum wall, possibly extending into the tissue surrounding abdominal organs but not yet reaching neighboring organs. The cancer progresses into the muscle layer or outermost wall layer of the colon or rectum and affects nearby lymph nodes.
   In Stage 3C, the cancer has advanced beyond the colon or rectum wall and invaded the tissues lining abdominal organs without spreading to adjacent organs. Cancer cells are identified in over six nearby lymph nodes. It can be breached through the colon or rectum wall or spread into abdominal organ linings with seven or more affected nearby lymph nodes. While the long term outcomes are poorer than the stage 1 and 2, these patients also do very well if they have a good response to neoadjuvant chemoradiation in rectal cancers . In colonic cancers they require radical surgery with good margins .
4. Stage 4 of colorectal cancer: It is the metastatic colorectal cancer that has spread beyond the colon or rectum to distant parts of the body, including various tissues and organs. The liver is the commonest site of metastatic spread. Some other areas of involvement are higher lymph nodes , lungs , bones or brain.
   Liver metastasis is treatable completely in many cases with a combination of chemotherapy with targeted therapy first followed by aggressive surgery. Lung metastasis if few in number can also be surgically treated. It is essential to seek prompt medical intervention based on the stage and location of the tumor. The treating doctor will decide on an individualized treatment plan for you. Early detection and treatment are key to saving lives.