Benefit Seen With Laparoscopic Proximal Gastrectomy For Upper Third Early Gastric Cancer

Laparoscopic proximal gastrectomy with double tract reconstruction saw less vitamin B12 supplement vs laparoscopic total gastrectomy without compromising the complication rate and survival in patients with upper third early gastric cancer, according to results from the KLASS-05 randomized trial (NCT02892643) presented at the International Gastric Cancer Congress 2022.

Two years post-surgery, hemoglobin change was 5.6% +/- 7.4% in the proximal gastrectomy group (n = 68) compared with 6.9% +/- 8.3% in the total gastrectomy group (n = 69) for the intention-to-treat population (ITT; P = .349). In the per-protocol (PP) population, the hemoglobin change was 5.2% +/- 6.8% and 7.5% +/- 7.8% in the proximal (n = 63) and total gastrectomy (n = 65) groups, respectively (P = .082).

In the ITT population, 14.7% of patients received vitamin B12 supplementation in the proximal gastrectomy group compared with 58.0% of patients in the total gastrectomy group (P <.001). In the PP population, 12.7% and 58.5% of patients in the proximal and total gastrectomy groups received vitamin B12 supplementation, respectively (P <.001).

“Total gastrectomy is considered as the standard treatment for upper gastric cancer,” Do Joong Park, MD, PhD, associate professor, Department of Surgery and Cancer Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea, explained in his presentation of the research. “However, in the case of upper early gastric cancer and advanced Siewert type II gastroesophageal junction cancer, there is little metastasis to the distal lymph nodes, so there is a lot of evidence that proximal gastrectomy is possible.”

Co-primary end points of the study were 2-year hemoglobin change at post-gastrectomy and 2-year vitamin B12 cumulative supplement quantity at post-gastrectomy. Secondary end points included operative morbidity and mortality, quality of life, reflux esophagitis, relapse-free survival, and overall survival (OS).

Patients between the older than 20 and younger than 80 years with histologically proven adenocarcinoma, lesions on proximal stomach of 5 cm or less in size, who gave written consent were eligible for enrollment on the trial. Eligibility also required an ECOG performance status of 0 or 1; ASA class I, II, or III disease; no evidence of metastatic enlarged lymph node; and intent for curative resection.

In the ITT population, most patients were male in the proximal gastrectomy group and total gastrectomy group, respectively (57.4% and 69.6%), ASA classification II (47.1% and 47.8%), had an ECOG status of 1 (91.2% and 87.0%), and never smoked (64.7% and 55.1%). Characteristics were similar in the PP population, with most patients being male (55.6% and 72.3%), ASA classification II (47.6% and 50.8%), and never smoked (65.1% and 53.8%). Most patients had an ECOG status of 1 (92.1% and 86.1%)

Overall morbidity in the ITT population was 23.5% in the proximal gastrectomy group compared with 17.4% in the total gastrectomy group (P = .373). Local complications were observed in 13.2% and 11.6% of patients in those respective groups (P = .395). In the PP analysis, overall morbidity was 23.8% and 15.4% in the proximal and total gastrectomy groups (P = .229) with local complications seen in 14.3% and 7.7% of patients, respectively (P = .232). No cases of reoperation mortality were observed in either patient population.

In the ITT population, late complications were observed in 17.6% of patients in the proximal gastrectomy group vs 10.1% of patients in the total gastrectomy group (P = .306), with reflux esophagitis seen in 2.9% of patients in both respective groups. In this population, recurrence was observed in 1 and 2 patients in the proximal and total gastrectomy groups, respectively. One patient in the proximal gastrectomy group died.

Late complications in the PP population were reported in 14.3% and 10.8% of patients in the proximal and total gastrectomy groups, respectively (P = .738). In the proximal gastrectomy group, 1 patient experienced reflux esophagitis, 1 had recurrence, and 1 died. In the gastrectomy group, 2 patients experienced reflux esophagitis, 2 had recurrence, and none died.

Compared with the total gastrectomy group, both physical functioning (P = .025) and social functioning (P = 0.031) improved among patients in the proximal gastrectomy group. No OS differences were noted.

Reference

Park DJ, Han SU, Hyung WJ, et al. Laparoscopic proximal vs. total gastrectomy for upper third egc: Klass-05 randomized clinical trial. Presented at: International Gastric Cancer Congress 2022; March 6-9, 2022. Plenary session. Accessed March 7, 2022.