Long-term Outcomes of Laparoscopic Versus Open Surgery for Clinical Stage I Gastric Cancer: The LOC-1 Study.
BACKGROUND
Clinical trials comparing laparoscopic gastrectomy (LG) versus traditional open gastrectomy (OG) have been planned, their surgical outcomes reported but their oncologic outcomes are still pending. Consequently, we have conducted this large-scale historical cohort study to provide relevant information rapidly to guide our current practice.


METHODS
Through a consensus meeting involving surgeons, biostatisticians, and epidemiologists, 30 variables of preoperative information possibly influencing surgeons' choice between LG versus OG and potentially associating with outcomes were identified to enable rigorous estimation of propensity scores. A total of 4235 consecutive patients who underwent gastrectomy for gastric adenocarcinoma were identified and their relevant data were gathered from the participating hospitals. After propensity score matching, 1848 patients (924 each for LG and OG) were selected for comparison of long-term outcomes.


RESULTS
In the propensity-matched population, the 5-year overall survival was 96.3% [95% confidence interval (CI) 95.0-97.6] in the OG as compared with 97.1% (95% CI, 95.9-98.3) in LG. The number of all-cause death was 33/924 in the OG and 24/924 in the LG through the entire period, and the hazard ratio (LG/OG) for overall death was 0.75 (95% CI, 0.44-1.27; P = 0.290). The 3-year recurrence-free survival was 97.4% (95% CI, 96.4-98.5) in the OG and 97.7% (95% CI, 96.5-98.8) in the LG. The number of recurrence was 22/924 in the OG and 21/924 in the LG through the entire period, and the hazard ratio was 1.01 (95% CI, 0.55-1.84; P = 0.981).


CONCLUSIONS
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.
*Department of Gastroenterological Surgery, Gastroenterological Center, Cancer Institute Hospital of Japanese Foundation for Cancer Research, Tokyo†Department of Surgical Oncology, National Cancer Center Hospital East, Chiba‡Department of Digestive Surgery, Niigata Cancer Center Hospital, Niigata§Department of Preventive Medicine and Public Health, Biostatistics at Center for Clinical Research, Keio University School of Medicine, Tokyo¶Department of Surgery, Center for Healthcare Outcomes and Policy, University of Michigan, Ann Arbor, MI||Department of Computer and Information Science, Seikei University Faculty of Science and Technology, Tokyo**Department of Health Promotion and Human Behavior, Kyoto University Graduate School of Medicine/School of Public Health, Kyoto.
Michitaka
M
Honda
Naoki
N
Hiki
Takahiro
T
Kinoshita
Hiroshi
H
Yabusaki
Takayuki
T
Abe
Souya
S
Nunobe
Mitsumi
M
Terada
Atsushi
A
Matsuki
Hideki
H
Sunagawa
Masaki
M
Aizawa
Mark A
MA
Healy
Manabu
M
Iwasaki
Toshi A
TA
Furukawa
D000230:Adenocarcinoma / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D015331:Cohort Studies; D005260:Female; D005743:Gastrectomy; D006801:Humans; D010535:Laparoscopy; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D057216:Propensity Score; D013274:Stomach Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D016896:Treatment Outcome