Colon and Rectal Cancer
Colorectal cancer is a cancer that starts in the colon or the rectum. Most
of these cancers begin as a polyp or growth on the inner lining of the
colon or rectum, which is often detected through a diagnostic procedure
known as a colonoscopy. In this procedure, a long, flexible tube with
a small video camera on the end is inserted through the patient’s
rectum and into the colon. The camera transmits images of the lining of
the colon on a screen so the doctor can examine it for any abnormalities.
Some polyps can change into cancer over time, but not all polyps become
cancer. Surgery is often the main treatment for earlier-stage colon cancers.
The type of surgery used depends on the stage of the cancer, where it
is, and the goal of the surgery.
Treatments
Polypectomy
Removal of early stage cancer or polyps during a colonoscopy.
Local excision
This is a slightly more extensive procedure that can be used to remove
superficial cancers and a small amount of nearby tissue from the wall
of colon.
Colectomy
In this procedure, surgeons remove all or part of the colon. Nearby lymph
nodes are removed as well.
Hemicolectomy, partial colectomy, or segmental resection
Removal of the part of the colon with the cancer and a small segment of
normal colon on either side of the cancer. Usually, about one-fourth to
one-third of your colon is removed, but this depends on the size and location
of the cancer. The remaining sections of your colon are then reattached.
Nearby lymph nodes are removed at this time as well.
Total colectomy involves removing the entire colon.
This procedure is not often needed to treat colon cancer. It is generally
used only if there is disease in the part of the colon without the cancer,
such as hundreds of polyps (in someone with familial adenomatous polyposis)
or inflammatory bowel disease. A colectomy can be done in 2 ways:
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Open colectomy: The surgery is done through a single long incision in the abdomen.
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Laparoscopic-assisted colectomy: This minimally invasive procedure requires several small incisions. A
laparoscope, a thin lighted tube with a small video camera on the end,
is inserted through one of the incisions and enables the surgeon to see
inside the abdomen. Special long instruments are inserted through the
other incisions to remove part of the colon and lymph nodes.
Colostomy
Similar to a colectomy that’s done to remove the cancer, but instead
of reconnecting the segments of the colon, the top end of the colon is
attached to an opening (stoma) in the skin of the abdomen to allow stool
to leave the body. A removable collecting bag is attached to the stoma
to hold the waste.
Ileostomy
In this procedure, an opening in the abdominal wall that is made during
surgery and the end of the small intestine (the ileum) is connected to
a stoma in the skin. A removable collecting bag is attached to the stoma
to hold the waste. Once you are healthier, another operation can be done
to attach the ends of the colon back together or to attach the ileum to
the colon. Rarely, if a tumor can’t be removed or a stent placed,
the colostomy or ileostomy may need to be permanent.
Diverting colostomy
Some patients have colon cancers that have spread but also have tumors
blocking the colon. For patients with this problem, sometimes surgery
is done to relieve the blockage without removing the part of the colon
containing the cancer. Instead, the colon is cut above the tumor and attached
to a stoma to allow stool to leave the body. This procedure can often
help the patient recover enough to start other treatments, such as chemotherapy.
Low anterior resection
This procedure may be performed for advanced rectal cancers. It involves
removing the rectum and part of the colon. Radiation and chemotherapy
often precede surgery. The rectum is removed, and the colon is attached
to the area just above the anal sphincter muscles. Our surgeons can remove
even very low (distal) rectal cancers in order to avoid a permanent colostomy.