Some colon cancer patients survive longer than the others. Now, a new research suggests that this may have something to do with the location of the tumor.
Experts said that the discovered link between the location of the colon cancer and the patient's chances for survival will likely lead to changes on how doctors provide treatment depending on which side the colon cancer originated.
In a new study involving more than 1,000 individuals whose colon cancer had spread, researchers have found that those whose tumor was located on the right survived an average of 19 months. The survival of those whose tumor was located on the left side, however, was longer at 33 months.
Colon cancer that started on the right side appears to be different from colon cancer that started on the left side, said Alan Venook, a study researcher from the University of California, San Francisco.
The researchers also said that colon cancer that started on the right need to be treated differently than colon cancer that originated on the left side, since patients who had left-sided tumors appear to have a much better prognosis compared with their counterparts who had right-sided tumor.
This could be partly due to right sided polyps are often flat, which makes them more difficult to spot during colonoscopy, so they eventually turn into cancer.
The results of the study likewise suggest that colon cancer is not one disease but a number of different diseases.
"Each side of the colon starts in a different place, which is why the cancers are biologically different," Venook said. "We don't have just colon cancer, but varieties of colon cancer, and some have better prognosis than others."
Venook added that the findings of the research, the largest study to date that focused on the location of colorectal tumor, could potentially change how colon cancer is treated. It also offered answers as to why some patients do better than the others.
"[T]he biology of the colon on the right side is different from the biology on the left side," Venook said. "Previous research suggested that tumor location could affect clinical outcomes, but the effects we observed in this trial appeared to be far great than we expected."
Although the death rate from colorectal cancer has been on a decline for several decades, the condition remains as one of the leading causes of cancer-related deaths in the U.S. It is expected to cause 49,190 deaths in 2016, according to estimates of the American Cancer Society.
