Laparoscopy Lead to Better OS, Noninferior RFS Vs Open Gastrectomy in Advanced Gastric Cancer

Noninferiority of laparoscopic surgery compared with an open gastrectomy for patients with advanced gastric cancer was confirmed at the 5-year follow-up of the KLASS-02-RCT trial (NCT01456598), which was presented at the 2022 International Gastric Cancer Congress.¹

The 5-year overall survival (OS) rate was 88.9% in the laparoscopy group and 88.7% in the open procedure group (log-rank test, P = .297). The 5-year relapse-free survival (RFS) rate was 79.5% in the laparoscopy group and 81.1% in the open procedure group (log-rank test, P = .658).

“The laparoscopic approach can be recommended in patients with locally advanced gastric cancer to get the benefits of the low incidence of late complications,” Sang-Yong Son, MD, Department of Surgery, Ajou University School of Medicine in Suwon, Korea, said during the presentation.

Previous results at the 3-year follow-up showed fewer early complications in the laparoscopy group at 16.6% vs 24.1% in the open procedure group (P = .003).² Additionally, patients in the laparoscopy group experienced less pain and analgesic use (P = .017) and had faster recovery, at 8.1 days compared with 9.3 days in the open procedure group (P = .005).

Data at the 3-year timepoint failed to show a numerical difference in the RFS rate between the 2 groups, at 80.3% in the laparoscopy group and 81.3% in the open procedure group (P = .726). After adjustment for surgeon factors, the hazard ratio for RFS was 1.035 (P = .039). Similarly, the 3-year OS rates were 90.6% vs 90.3%, respectively (P = .961).³

Son noted the aim of this study was to determine 5-year OS outcomes of the laparoscopy and open procedure groups . Investigators also evaluated secondary end points of long-term complication and the 3-year RFS rate, to see if this could be a surrogate for OS at 5 years.

A total of 974 patients were included in this analysis. Patients were excluded if they had no surgery or resection after randomization, failed to achieve R0 resection, or had a confirmed distant metastasis within 21 days after surgery.

Of the 1050 patients who were originally randomized in a 1:1 fashion in the phase 3 trial, 6 patients crossed over to the laparoscopic group and 11 crossed over to the open procedure group. The 5-year follow-up analysis included 492 patients in the laparoscopic group and 482 in the open procedure group. The median follow-up time was 69.4 months.

Median patients age was 59.8 years in the laparoscopic group and 59.4 years in the open procedure group. Most patients in both groups were men. In the laparoscopy group, 477 patients (97.0%) had a distal gastrectomy vs 470 (97.5%) in the open procedure group. Total gastrectomy was performed in 15 (3.0%) and 12 (2.5%) patients in the laparoscopy and open procedure groups, respectively. Adjuvant chemotherapy was administered in 60.6% of patients in the laparoscopic group with 76.1% having completed treatment; in the open procedure group, those rates were 62.0% and 75.4%, respectively.

The laparoscopic group was most often characterized by peritoneal recurrence in 40.9%, hematogenous in 20.4%, mixed in 15.1%, locoregional in 11.8%, and by distant lymph node metastases in 11.8%. In the open procedure group, recurrence was characterized as peritoneal in 43.7%, hematogenous in 21.3%, locoregional in 15.0%, mixed in 12.5%, and by distant lymph node metastases in 7.5%. There were no significant intergroup differences (P = .619).

The number of recurrences was higher in the laparoscopy group (n = 93) than the open procedure group (n = 80) overall, but the differences were not found to be significant (P = .702). In both groups, most recurrences occurred in the first 3 years. After the 3-year point, recurrences tended to be numerically higher in the laparoscopy group.

The correlation between the 3-year RFS and 5-year OS for the full-set analysis was characterized by a Spearman Rho value of 0.447 (95% CI, 0.393-0.498). Stage I disease was characterized by a correlation of Rho 0.242 (95% CI, 0.138-0.341), stage II by 0.469 (95% CI, 0.373-0.555), and stage III by 0.720 (95% CI, 0.655-0.775).

Overall complications were observed in 32 patients (6.5%) in the laparoscopic group and 53 (11.0%) in the open procedure group (P = .011). Highest rates of complications included intestinal obstruction (2.6% vs 5.0%, respectively; P = .056) and chronic wound complications (0.6% vs 1.9%; P = .077). Major complications of grade 3 or higher were seen in 2.8% of patients in the laparoscopic group and 4.4% the open procedure group (P = .777).

References

1. Son SY, Hur H, Hyung WJ, et al. 5-year outcomes of KLASS-02-RCT: laparoscopy vs. open distal gastrectomy for locally AGC. Presented at: 2022 International Gastric Cancer Congress; March, 6-9, 2022; Houston, TX.

2. Lee HJ, Hyung WJ, Yang HK, et al. Short-term outcomes of a multicenter randomized controlled trial comparing laparoscopic distal gastrectomy with D2 lymphadenectomy to open distal gastrectomy for locally advanced gastric cancer (KLASS-02-RCT). Ann Surg. 2019;270(6):983-991. doi:10.1097/SLA.0000000000003217

3. Hyung WJ, Yang HK, Park YK, et al. Long-term outcomes of laparoscopic distal gastrectomy for locally advanced gastric cancer: the KLASS-02-RCT randomized clinical trial. J Clin Oncol. 2020;38(28):3304-3313. doi:10.1200/JCO.20.01210