SAN FRANCISCO – Patients with early gastric cancer have less postoperative morbidity if they undergo laparoscopic instead of open distal gastrectomy, according to safety results of a phase III trial presented at the at the annual Gastrointestinal Cancers Symposium sponsored by the American Society of Clinical Oncology.
The trial – the first in a series by the Korean Laparo-endoscopic Gastrointestinal Surgery Study Group (KLASS-01) – was conducted among 1,416 patients with clinical stage I disease in Korea, where the proportion of esophagogastric cancers caught in early stages has increased with the introduction of a national screening program. The patients were randomized evenly to laparoscopic or open surgery.
Main results showed mortality was similarly low for the open and laparoscopic approaches. But the laparoscopic group had half the rate of wound complications and, in multivariate analysis, a 41% lower risk of postoperative morbidity.
“Laparoscopy-assisted distal gastrectomy for patients with clinical stage I gastric cancer is safe and has a benefit of lower occurrence of wound complications compared with conventional open surgery,” concluded first author Dr. Hyuk-Joon Lee, a gastrointestinal surgeon at the Seoul National University Hospital, Korea.
Dr. Hyuk-Joon Lee
Invited discussant Dr. Michael Kent of Harvard Medical School, director of minimally invasive thoracic surgery at Beth Israel Deaconess Medical Center, Boston, said, “It is clear that the KLASS study is the largest by far to evaluate laparoscopic gastrectomy.”
A similar trial in the setting of early colorectal cancer (N. Engl. J. Med. 2004;350:2050-9) led to rapid uptake of laparoscopic resection for those patients at high-volume centers, he noted. “Although we still await survival data from the KLASS study, I anticipate that laparoscopic gastrectomy will likewise become the preferred approach in high-volume centers, especially in countries such as Korea with a national screening program.
“However, I do not think that open gastrectomy is an operation of the past,” he added. “For one, the benefits have not been shown yet in advanced gastric cancer. Also, in low-volume centers, the expertise in laparoscopic surgery may not be sufficient to warrant this approach. I should also add that body habitus may render this operation more difficult in obese patients.”
Dr. Kent pointed out that patients with T1a disease have yet another option, endoscopic resection, which has been found to yield good results at least in a single-center retrospective study (Surg. Endosc. 2013;27:4250-8). “In regards to future clinical trials, I believe it would be important to determine which patients require surgical as opposed to an endoscopic resection,” he concluded.
Dr. Michael Kent
A previously reported interim analysis of the KLASS-01 trial showed no significant difference in morbidity and mortality between the laparoscopic and open groups, allowing the trial to continue (Ann. Surg. 2010;251:417-20).
Eighty percent of patients on the trial had T1 disease. Within this subset, about 60% had T1a and 40% had T1b disease, Dr. Lee said.
In modified intention-to-treat analyses, patients in the laparoscopic group had a longer operation time (185 vs. 146 minutes) and fewer lymph nodes retrieved (41 vs. 43). But they had a lower estimated blood loss (119 vs. 194 mL) and shorter hospital stay (7.2 vs. 8.0 days).
The rate of surgical mortality was less than 1% and the rate of reoperation was about 1%, with no significant differences between groups.
Patients in the laparoscopic group had lower 30-day rates of postoperative morbidity (13.7% vs. 18.9%, P = .009), and the benefit of the less invasive approach remained significant after multivariate adjustment (odds ratio, 0.59; P = .001). Wound complications were half as common with laparoscopy (3.6% vs. 7.0%, P = .005).
Data on 5-year overall survival, the primary endpoint of the KLASS-01 trial, are expected later this year.
Dr. Kent asked, “In your country, for those patients with clinical T1a disease, how is a decision made regarding therapy?”
“I think if we can accurately diagnose the T stage as well as the N stage, we can surely adapt the endoscopic treatment for all the T1a cancer patients,” Dr. Lee replied. Such diagnosis has proved challenging, he added. Endoscopic resection is usually reserved for patients with tumors less than 2 cm in diameter showing differentiated histology and not invading the mucosa. “We have to move to the more accurate diagnosis of the TNM stage,” he concluded.