NEW YORK (Reuters Health) - Patients with clinical stage I gastric cancer do as well oncologically five years after laparoscopic gastrectomy (LG) as they do after open gastrectomy (OG), according to an observational study from Japan.
"While it is known that LG has similar postoperative outcomes to open surgery, this is the first study of its kind to show that long-term oncological outcomes are also similar for these two procedures," the authors wrote in their study online January 27 in Annals of Surgery.
"This observational study adjusted for all-known confounding factors seems to provide strong enough evidence to suggest that LG is oncologically comparable to OG for gastric cancer," they wrote.
Lead study author Dr. Michitaka Honda of the Cancer Institute Hospital of the Japanese Foundation for Cancer Research, in Tokyo, and colleagues consulted with surgeons, biostatisticians, and epidemiologists to identify 30 variables of preoperative information that may influence a surgeon's choice between LG and OG and may be associated with outcomes.
The authors identified 4,235 consecutive patients who underwent gastrectomy for gastric adenocarcinoma and gathered their relevant data from the participating hospitals. After propensity score matching, they selected 924 patients who had received LG and 924 who had received OG, and they compared their long-term outcomes.
Overall, the five-year survival was 96.3% in patients receiving OG compared with 97.1% in those receiving LG.
The number of all-cause deaths was 33 in the OG group and 24 in the LG group, and the hazard ratio (LG/OG) for overall death was 0.75.
The three-year recurrence-free survival in the OG group was 97.4% and 97.7% in the LG group. Recurrence was found in 22 patients in the OG group and in 21 in the LG group, and the hazard ratio was 1.01.
Dr. Yanghee Woo, director of gastroenterology in the Minimally Invasive Surgery Program at City of Hope in Duarte, California, told Reuters Health by email that the study has the greatest impact on patients in Japan and South Korea, where the incidence of early gastric cancer is higher.
"The long-term survival rates for the early gastric cancer patients reported in this study are also consistent with previously reported outcomes from Japan and South Korea. However, these outcomes are significantly better than for those patients with Stage I disease in the United States," Dr. Woo said.
"In the U.S., fewer than 10% of gastric cancer operations are currently performed laparoscopically. Most U.S. patients undergoing radical gastrectomy have locally advanced, not early, gastric cancer, which this study does not address," she said.
"I believe that the low rate in the U.S. is due, not to the lack of evidence of long-term outcomes for early gastric cancer, but to the learning curve of advanced gastric cancer surgery and the short-term and long-term outcomes of laparoscopic radical gastrectomy for advanced gastric cancer," she added.
"This very well-done study adds more validity to the use of minimally invasive surgery for cancer and demonstrates that the minimally invasive approach does not result in inferior oncologic outcomes," Dr. Michael L. Kendrick, professor of surgery and chair of the Division of Subspecialty General Surgery at the Mayo Clinic College of Medicine in Rochester, Minnesota, told Reuters Health by phone.
"This objective study is important to patients and their physicians, and it pushes us a bit further in understanding that these approaches are not only safe but may have some advantages for cancer," added Dr. Kendrick, who was not involved in the study.
Dr. Kendrick noted that physicians will be able to apply these results to areas other than gastric cancer. "As an oncologic surgeon treating gastric, pancreatic, and liver cancer, this study adds support for the noninferiority and possible advantages of minimally invasive approaches over open approaches," he said.
Dr. Steven Hochwald, chief of gastrointestinal surgery and vice chair of the Department of Surgical Oncology at Roswell Park Cancer Institute in Buffalo, New York, told Reuters Health by phone, "I agree completely with the findings of this study. Many of us adopted laparoscopic gastric surgery for gastric cancer several years ago, but in western countries, LG has generally been slow to be adopted."
"The Asian countries do a lot more LG," Dr. Hochwald said. "They see a lot more gastric cancer in general and early gastric cancer than we do in the west, and they also see a lot of cases that have lower body mass indexes, which makes LG more amenable and easier to accomplish."
"I think that laparoscopic gastric surgery and robotic surgery will be adopted more widely in the west over the next several years and that this will help improve our ability to do minimally invasive surgery for gastric cancer," he added.
Dr. Honda did not respond to requests for comment.
The authors reported no external funding or disclosures.
Ann Surg 2016.