The right and left of colon cancer
Did you know that the survival chances in colorectal cancer depend on which side the cancer is located? Several studies in recent years have shown that patients with colon cancers on the right side have worse short- and long-term survival rates than those with left-sided tumors, regardless of the stage of the disease at diagnosis or the nature of the treatment. The reason for this distinction is the different embryological origins of the right- and left-sided colon.
Besides, left-sided tumors have rounded masses, which are easier to detect in the early stages. Right-sided tumors, on the other hand, have flat masses that are difficult to detect. These are more likely to develop in patients who have a genetic predisposition to colorectal cancer.
Even the therapy responses are totally different. Left-sided colorectal cancer patients benefit more from chemotherapies such as 5-fluorouracil (5-FU)-based regimes, and targeted therapies such as anti- epidermal growth factor receptor (EGFR) therapy. They also have a better prognosis.
Right-sided colorectal cancer (RCRC) patients do not respond well to conventional chemotherapies, but demonstrate more promising results with immunotherapies. A 2018 publication by the American College of Surgeons in Science Daily elucidated that right-sided colon cancer survival can be improved with more lymph nodal resection. .
Notably, there is more to cancer than what meets the eye and the colon is no exception. One must recognise that colon cancer is not one type of disease. Rather, it is two different diseases in the same organ. Understanding the characteristics of these two entities is important for developing effective therapies.
Know more about colorectal cancer here.
This article has been written by Dr. Amit Bhatt, Medical Oncologist, Director, Avinash Cancer Clinic, Pune.