Monday, August 29, 2016
Can a cancerous tumor of the colon be passed through the rectum?
Thank you for your question. I am uncertain exactly what you are asking so let me answer this two ways. If it does not answer your inquiry, perhaps you could provide us with more information.
If you are asking if colon cancers can spread to the rectum, the answer is unlikely.
People who have a cancer in the rectum and colon (two tumors) likely have what is called synchronous disease. This means that they developed cancer at two separate sites. The occurrence of this phenomenon is rare, and depending on the report you read, less then about 4%. It is more common to have a cancer somewhere in the colon and have a polyp in the rectum.
There are case reports in the medical literature of "seeding" tumor cells to hemorrhoidectomy sites in the rectum. This is where a cancerous polyp was removed in the colon by a colonoscope in a patient that also had hemorrhoid surgery and they then develop cancer at the hemorrhoid site. It was speculated that the cancer at the hemorrhoid site was caused by tumor cells that spread to there from the polyp site. But again, this is speculation and not proven. It is believed by many however, that tumor cells can spread by direct contact, and theoretically could spread within the colon to the rectum, but again this is not proven.
If you or someone you know has a cancer in the colon and another one in the rectum, it is more likely that it is the result of synchronous disease (two separate tumors) then spread through the lumen of the intestine.
James I Merlino, MD
Assistant Professor of Surgery
School of Medicine
Case Western Reserve University