Patients who undergo laparoscopy-assisted colectomy (LAC) have increased survival rates in addition to decreased surgical morbidity in comparison with those who have an open surgical colectomy (OC), according to a recent study. Antonio M. Lacy, MD, of the Hospital Clinic of the University of Barcelona, Spain, and colleagues reported these findings in the June 29 issue of Lancet (2002;359:2224–2229).
This randomized trial compared the two methods in 219 patients with Stage I, II, or III colon cancer (108 underwent OC and 111 had LAC). All of the procedures were done at the University of Barcelona by a surgical team with considerable LAC experience. Although previous studies have compared morbidity and quality of life, this was the first randomized clinical trial to directly compare long-term survival in the two different operations.
Lacy and colleagues observed ten colon cancer deaths (nine percent) among the LAC patients and 21 such deaths (21 percent) among the OC patients during the average four-year follow-up period after surgery. About 17 percent of LAC patients had cancer recurrences during that time compared with 27 percent of OC patients. The LAC patients also had less blood loss during surgery, they recovered bowel peristalsis 19 hours earlier, resumed oral food and liquid intake 30 hours earlier, and were discharged from the hospital three days sooner.
Lacy suggested the study results show that LAC should be preferred to OC in patients with colon cancer because it reduces problems related to surgery, shortens hospital stays, and prolongs cancer-related survival.
Survival Advantage Was Unexpected
Based on prior reports, Lacy and colleagues, “… expected to show that patients treated with LAC would have lower morbidity and shorter hospital stays than those treated with OC, but that tumor recurrence and survival would be unaffected by the choice of treatment.” They were surprised to find that LAC patients also had fewer recurrences and longer survival rates. Another unexpected finding was that the improvements in overall and recurrence-free survival were due to marked improvements for Stage III patients, whereas the choice between LAC and OC had no significant effect on these outcomes for Stage I and Stage II patients.
The authors were not sure why more LAC patients survived long-term, but suggested that the laparoscopic procedure might be less stressful and cause less immune system impairment than an OC would, thereby reducing the patients' resistance to growth of metastases. And it's also possible the LAC surgeons were especially careful to minimize intraoperative manipulation of tumor tissue, and that tumor manipulation could promote exfoliation of the malignant cells and their intraperitoneal and intravascular spread. Those explanations fit well with the fact that most of the survival benefit shown was among patients with Stage III colon cancer, Lacy wrote.
Study Not the Final Word
“The favorable results of laparoscopic assisted colectomy for Stage III colon cancer reported in this well-designed, randomized trial are very interesting but merit careful review,” said Alan Thorson, MD, Director of the Colorectal Surgery Program at Creighton University School of Medicine in Omaha, NE. “Similar results need to be confirmed in other institutions before surgeons rush to change their practice patterns.”
Thorson said there are several points to consider in this trial. He noted that the authors do not mention statistical analysis comparing the baseline characteristics of patients in the LAC and OC groups. “There were twice as many T4 tumors (10 versus 5) in the OC as in the LAC group. How many of these patients were Stage III?” he asked. “Since the extent of primary tumor was highly associated with overall and cancer-related survival in univariate analysis (p < 0.0001), this information would seem particularly important.”
A similar question arises with respect to tumor differentiation. “The LAC group had only nine undifferentiated tumors compared with 14 in the OC group,” said Thorson, who serves on the National Board of Directors of the American Cancer Society.
“The rate of conversion from LAC to OC is not stated,” Thorson said. “In the COST study analysis in the United States (JAMA 2002;287:321–328), this rate became a critical factor in the overall lack of difference in short-term quality of life (QOL) benefits noted between LAC and OC. When analyzed according to an intention-to-treat basis, a converted procedure is analyzed as an LAC procedure, which places essentially OC data into the analysis of LAC results,” he said. “Although an appropriate analysis, a high conversion rate may adversely affect the LAC outcome. In the case of the COST analysis, the conversion rate was 25 percent. If conversion rates are reduced, QOL differences might be significantly altered. The conversion rate in this trial would be of interest.
“It is prudent to say that LAC should still be considered investigational. There remain many unanswered questions that need continued study in a well-controlled environment,” said Thorson. “However, LAC continues to hold great promise for reducing the discomfort and down-time associated with major abdominal surgery. As technical equipment and expertise continue to evolve, minimally invasive procedures will likely have an increasing role to play in the surgical armamentarium,” Thorson concluded.