(The New York Times News Service) -- A less invasive surgical technique for removing colon cancers is superior to the standard operation because it can reduce the risk of the cancer recurring and improve a patient's chances for survival, according to a new study by Spanish doctors.

The newer technique, known as laparoscopy, also shortened the hospital stay and led to fewer post-operative complications among patients whose cancer had not spread, the doctors report in the June 29 issue of the Lancet.

In laparoscopy, surgeons see through a small camera and work with instruments that are inserted through small holes in the abdomen. Laparoscopy has been widely used to perform gallbladder surgery in the United States and Europe over the past decade, and it has been tried for other conditions.

But in the United States, laparoscopy has been used far less often for colon cancer and has been controversial in part because of the lack of rigorous studies showing its benefits. Some earlier reports suggested shorter hospital stays, but other studies found as many as 21 percent of the colon cancers recurring in the scars from laparoscopy. Also, laparoscopic surgery requires practice and skill that only a small number of colon cancer surgeons have acquired.

Colon cancer will be diagnosed in an estimated 107,300 Americans this year, making it the third most common cancer among men and women in the United States, the American Cancer Society said.

Many polyps that are on the verge of becoming cancerous or that have developed early cancer can be removed when doctors insert a flexible tube through the anus into the bowel in a nonsurgical procedure known as a colonoscopy. But most advanced colon tumors are removed in an operation that requires an incision 8 to 12 inches long.

The Spanish study is the first to directly compare cancer recurrence and survival in laparoscopy and standard colon cancer surgery in a randomized controlled trial.

In it, the participants agreed to leave the choice of operation to the statistical equivalent of flipping a coin. The surgical team, led by Dr. Antonio M. Lacy, was skilled in laparoscopy and performed both types of operations at the University of Barcelona.

Lacy's team compared the two procedures on 219 patients from November 1993 to July 1998. Those who had laparoscopic surgery stayed in the hospital for five days, three days less than patients who had the standard operation. But other surgeons noted that patients undergoing the standard operation in American hospitals now tended to stay about six days.

Of 111 patients who underwent laparoscopic colon surgery, 12 developed complications, compared with 31 in the group of 108 who had the standard operation.

Patients in the laparoscopic group were 60 percent less likely to have recurrence of the cancer than those who underwent the standard operation.

"If these results were confirmed by ongoing multicenter randomized trials, laparoscopy would become the standard surgical approach to patients with colon cancer," Lacy said.

A number of studies involving thousands of patients in the United States and elsewhere are in progress.

In 1994, the American Society of Colon and Rectal Surgeons said that laparoscopic colon cancer surgery should be performed only in a scientifically controlled trial.

Dr. Alfred M. Cohen, a colon cancer specialist who also directs the Lucille P. Markey Cancer Center at the University of Kentucky in Lexington, said in an interview that the Spanish study was "well done and well analyzed" and would "generate a flurry of activity."

About 50,000 Americans with colon cancer could benefit from laparoscopic techniques each year if other studies confirm the Spanish trial, Cohen said.

Laparoscopic surgery leaves smaller incisions than standard operations, leading to their description as pinhole and keyhole surgery. But the laparoscopic incisions are larger than pinholes: for a colon cancer operation, a surgeon makes four or five incisions about 1/4 to 1/2 inch in length through which the camera and instruments are inserted into the abdomen.

An additional incision of 2 to 3 inches is made through which the bowel is brought out from the abdomen to remove the cancerous section and the two ends of the bowel are sewn together.

Lacy's team said it did not know why laparoscopy led to a lower recurrence rate and thus longer survival. One theory is that surgical stress impairs immunity and laparoscopy reduced such stress. Another theory is that there was less spread of cancer cells in laparoscopy.

Cohen theorized that earlier recovery from laparoscopy may allow patients to start chemotherapy earlier.

Copyright 2002 The New York Times News Service. All rights reserved.