Treatment for colon cancer depends on how invasive it is and whether it’s metastatic, meaning that it’s spread.

Although treatments vary some, colon cancer must be cut out, with an adequate margin of healthy cells to be sure that it’s all been removed. Dr. Brent Christensen said that surgeons go for a 5- centimeter margin all around it, at a safe minimum.

Christensen, vice chairman of the Department of Surgery at LDS Hospital, and Dr. Leslye Ingersoll, a radiation oncologist at Utah Valley Regional Medical Center, will be featured in today’s Deseret Morning News/Intermountain Health Care Hotline. From 10 a.m. to noon, they’ll take calls about colon cancer and screening, as well as offer some prevention tips.

When a tumor in the colon is removed, along with the lymph nodes, the remaining sections are rejoined. Then the surgeon “explores the abdomen and looks at the liver to make sure it’s not a metastatic tumor.”

If the tumor has spread, some surgeons will remove tumors from the liver, as well. Others will refer the patient to a liver specialist, depending on how much experience he or she has with livers, he said.

A pathologist examines what has been removed to see how far into the colon wall the cancer extends. If it is on the surface and lymph nodes are not involved, it’s a stage 1 tumor, which has about a 95 percent chance of a cure without further care.

Follow-up colonoscopies, blood tests and examinations then take place at three months, six months and yearly after that if there’s no recurrence.

When the tumor extends deeper into the muscle but hasn’t reached the lymph nodes, it’s stage 2 with a 70 percent chance of survival with surgery alone. (There’s a different classification system, called Duke’s A, B, C or D that is comparable to the stages 1 to 4).

At stage 3 — in the lymph nodes and deeper into the wall — surgery alone yields only a 30 percent cure rate. Chemotherapy is added and improves the cure rate to 70 percent.

“Chemotherapy for colon cancer was not considered a good option until about the 1990s,” Christensen said. “Then a combination was developed that worked very well.”

Radiation is also used with colon cancer.

At stage 4, metastatic, in the lungs, liver, etc., the prognosis is “very poor,” he said.

That’s why screening is so important. A colonoscopy can detect precancerous changes in the colon, like polyps, that can be removed before they become a problem.

“I think people are a lot better over the years. We see more people coming in, they’re not afraid of it (the colonoscopy),” Christensen said. But there are holdouts. “Some people do a little ostrich, head in the sand.”

Colonoscopy, where a specialist examines the colon with a scope, is considered the gold standard screening, he said, because early changes can be removed, suspicious sections biopsied.

But Christensen believes that there is a place for “virtual colonoscopy” as well. It’s a CT scan of the colon. But the hard part of a colonoscopy is the preparation to clean out the bowel. You need that for a scan as well.

The virtual colonoscopy will see lesions down to 1 centimeter in size but not smaller ones. He believes the virtual colonoscopy will come into its own when so many people have gotten the message on screening that those who do colonoscopies can’t keep up.

The virtual test may become the initial screening, but for that to happen, prices would have to drop and insurance companies start paying for it. If the technology ever improves to pick up smaller lesions, that would make it more valuable as well, he said.

As for recovery, it depends on what is found. In most cases, someone with surgery for colon cancer will be in the hospital as much as a week, waiting for bowel function to return so he can eat and to make sure that bleeding, leaking or infection aren’t a problem.

Those who have laparoscopic surgery seem to recover a little faster, but it isn’t always possible to do the surgery that way.

If the cancer is too low in the rectum to resect and leave sphincter muscles intact, an individual must have a colostomy, where the bowel is channeled out through the wall of the abdomen into a bag.