Location matters when it comes to colon cancer and its treatment. Recent research shows that in treating right-sided colon cancer, removing a greater number of lymph nodes during surgery may improve prognosis.
One way that physicians classify colon cancers is whether they occur on the right or left side of the body. Right-sided colon cancer is located in the cecum, the ascending colon and the transverse colon that crosses the midsection from right to left. The left side of the colon includes the rest of the transverse colon, the splenic flexure, the descending colon, the sigmoid colon and the rectum.
Research shows that patients with tumors on the right side of the colon have lower five-year survival rates than patients with tumors on the left side. One study that examined 70,000 patients noted a five percent lower survival rate among patients with right-sided colon cancer.
However, through recent studies, researchers found removing more lymph nodes during colon cancer surgery may improve the prognosis of patients with right-sided colon cancer. These findings were presented at the 2018 American College of Surgeons (ACS) Quality and Safety Conference in Orlando, Florida.
Colorectal surgeons are trying to find new ways to improve surgical methods for patients with colon tumors on the right side. Right-sided colon cancer tends to be more difficult to treat, regardless of the stage at which it was diagnosed and the method used to treat it.
In the past, the protocol was to remove about twelve lymph nodes during surgery, regardless of the location of the tumor. Pathologists would analyze the lymph nodes to help determine the stage of colon cancer and recommend a course of treatment.
According to the new research presented at the ACS conference, survival rates may be improved by collecting more than 20 lymph nodes from patients with right-sided colon cancer. In a study that examined a sample of colon cancer patients between 2004 and 2014, survival rates increased by about 20 percent when surgeons removed 22 or more lymph nodes during the operation.
The left and the right colon form from different embryonic cells and therefore have separate sources of blood. They also have distinct microbiomes.
Patients who are predisposed to colon cancer are more likely to develop a tumor in the right colon. Right-sided tumors are usually more aggressive than left-sided tumors and are more likely to have a BRAF mutation, a type of colon cancer that is associated with poorer outcomes. Right-sided colon cancer is often diagnosed at a later, more advanced stage.
The right side of the colon is wider and is less likely to develop an obstruction, making it often more difficult to detect. Patients may experience more subtle changes like anemia or weight loss. The left colon is more narrow, so patients are more likely to notice changes in bowel habits like thin stools or blood in the stool.
Knowing the differences in right- and left-sided colon cancers helps physicians to create customized treatment plans for patients. Your GI doctor is available and ready to help, but you need to make the first move. The American Cancer Society recommends that all adults who are at average risk for colon cancer begin screening at age 45. If you have a family or personal history of colon disease or polyps, you should get screened earlier.
Talk to your gastroenterologist about when you should get screened. Young-onset colon cancer incidence has been steadily rising over the past decade, and studies show that young people are more likely to be diagnosed with advanced colon cancer.
You can begin colon screening at any age. Although the best colon screening is a colonoscopy, you can obtain an at-home stool test about $20. Colon cancer is the third-leading cause of cancer death in the United States, so get screened early and often.
Contact one of our outpatient GI centers for more information on how to get screened for colon cancer.