Mark W. Dobriner, M.D., F.A.C.S., F.A.S.C.R.S.
If colon and rectal cancers are detected early, 90% are curable. Unfortunately, by the time colon cancer is detected, approximately 60% of those cancers have already spread to either lymph glands or to distant sites (metastases.) That is why it is important to remember that the best treatment for colorectal polyps and for prevention of colorectal cancer is early detection by SCREENING COLONOSCOPY.
What happens after a patient is diagnosed with colon or rectal cancer? Once a patient is diagnosed, they are sent for a CT scan, PET scan, MRI, ultrasound, or a combination of these modalities in order to stage the cancer, which identifies the severity of the cancer. Staging determines whether some rectal cancers may benefit from preoperative radiation and chemotherapy treatment. When this is indicated, such a multidisciplinary approach contributes to our ability to preserve the sphincter (muscles of the rectum and anus) and improve the rate of cure.
There are several surgical options to treat colon and rectal cancers:
- Polypectomy and Local Excision
Most polyps (the precursors to colon and rectal cancer) and some early cancers can be removed during colonoscopy.
Open Colectomy (Colon Resection)
A colectomy removes part of the colon as well as the lymph nodes adjacent to the part of the colon that is being removed. The ends of the colon that have been divided are then reattached. This operation is performed through a single abdominal incision. Open colectomy is major surgery and requires a bowel preparation, general anesthesia and 2 to 7 days of hospitalization. Fortunately, most patients fully recuperate in 4 to 6 weeks.
- Laparoscopic Assisted Colectomy
Currently this is the most common method of surgical treatment of colon caner. This procedure entails the placement of ports (small tubes, 5-12 mm in diameter) through several very small abdominal incisions. A high definition camera is placed through one of the ports into the abdominal cavity. This camera projects the images onto monitors around the operating room table. Instruments to perform the surgery are placed through the other ports. When compared to open colectomy, resections performed in this manner have been shown to yield the same long term results with regard to cancer cure. Laparoscopic surgery significantly decreases post operative pain, slightly decreases the length of hospital stay as well as significantly shortening the recuperative period.
- Transanal Resection
Some polyps that are unable to be removed via colonoscopy and some very early rectal cancers of the distal rectum can be removed by a surgical approach through the anus. This surgery often allows the surgeon to leave the anus and sphincter intact so the patient can retain normal rectal function. This procedure is generally performed under local anesthesia as an outpatient.
- Low Anterior Resection (Sphincter Sparing Surgery)
Most rectal cancers cannot be removed by a transanal approach. In such cases, removal of a rectal cancer through the abdomen via an open or laparoscopic approach is indicated. After the affected area is removed, the colon is reconnected, allowing the patient to avoid a permanent colostomy. In other words, these methods allow patients to maintain the ability to have bowel movements in a normal way after surgery.
- Abdominoperineal Resection
This procedure removes the entire rectum and anus and requires the creation of a permanent colostomy. Due to advances in surgical techniques, this operation is performed much less frequently then it was years ago. After a portion of the colon and rectum is resected, pathological staging is performed to establish the severity of the cancer. The depth of penetration through the colon wall as well as the spread of cancer cells to the resected lymph nodes is determined. Staging determines whether or not Chemotherapy, Radiation Therapy, Targeted Therapies or a combination of these treatments is indicated.
Once again, the best approach to colon and rectal cancer is through prevention via screening. Even so, if you or a loved one is diagnosed with colon or rectal cancer, it is good to know that current surgical techniques are available that can often successfully treat the cancer and allow the patient continue to live a healthy and productive life.