{"entity":{"id":"klass-01","kind":"trial","name":"KLASS-01","aka":[],"tldr":"KLASS-01 showed that removing an early stomach cancer through keyhole surgery is as safe for long-term survival as open surgery and causes fewer wound complications, which made laparoscopic gastrectomy the standard for early gastric cancer in Korea and beyond.","summary":"KLASS-01 was a multicentre non-inferiority trial run by the Korean Laparoendoscopic Gastrointestinal Surgery Study group in patients with clinical stage I gastric adenocarcinoma. Patients were randomised to laparoscopy-assisted or open distal gastrectomy with standard lymph node dissection.\n\nThe short-term report found fewer wound complications and similar mortality with the laparoscopic approach. The primary analysis, published in JAMA Oncology in 2019, showed that five-year overall survival after laparoscopic surgery was non-inferior to open surgery. With the Japanese JCOG0912 trial it settled the question for early distal gastric cancer; the follow-on KLASS-02 addressed locally advanced disease.","status":"positive","asOf":"2026-09-17","links":[{"label":"ClinicalTrials.gov NCT00452751","url":"https://clinicaltrials.gov/study/NCT00452751"}],"tags":["subtype-trials"],"related":["paper-jcog0912-katai-lancet-gastroenterol-hepatol-2020"],"cancers":["early-gastric-cancer","gastric"],"sections":[],"technologies":[],"targets":[],"drugs":[],"companies":[],"institutions":["ncc-korea"],"pathways":[],"terms":[],"trials":[],"people":["hyung-ho-kim"],"bottlenecks":[],"keyPapers":["paper-klass-01-kim-jama-oncol-2019"],"journals":[],"dependsOn":[],"notes":[],"nct":"NCT00452751","phase":"3","setting":"Clinical stage I gastric cancer: laparoscopy-assisted distal gastrectomy against open distal gastrectomy, with five-year overall survival as the primary endpoint","sponsor":"National Cancer Center Korea (Korean Laparoendoscopic Gastrointestinal Surgery Study Group)","result":"Laparoscopic distal gastrectomy was non-inferior to open surgery for five-year overall survival in stage I gastric cancer, with fewer wound complications.","yearReported":2019,"enrolled":1400,"outcomes":[{"endpoint":"Overall survival at 5 years (non-inferiority)","primary":true,"unit":"%","arms":[{"name":"Laparoscopic distal gastrectomy","n":705,"value":94.2,"note":"Difference 0.9 percentage points; non-inferiority margin -5 points"},{"name":"Open distal gastrectomy","n":711,"value":93.3}],"p":"0.64","source":"https://doi.org/10.1001/jamaoncol.2018.6727"},{"endpoint":"Cancer-specific survival at 5 years","unit":"%","arms":[{"name":"Laparoscopic distal gastrectomy","n":705,"value":97.1},{"name":"Open distal gastrectomy","n":711,"value":97.2}],"p":"0.91","source":"https://doi.org/10.1001/jamaoncol.2018.6727"}]},"route":"/trials/klass-01/","neighbours":{"paper":[{"id":"paper-jcog0912-katai-lancet-gastroenterol-hepatol-2020","kind":"paper","name":"JCOG0912: laparoscopy-assisted versus open distal gastrectomy for clinical stage IA or IB gastric cancer","route":"/key-papers/paper-jcog0912-katai-lancet-gastroenterol-hepatol-2020/"},{"id":"paper-klass-01-kim-jama-oncol-2019","kind":"paper","name":"KLASS-01: laparoscopic versus open distal gastrectomy for stage I gastric cancer, long-term survival","route":"/key-papers/paper-klass-01-kim-jama-oncol-2019/"}],"cancer":[{"id":"early-gastric-cancer","kind":"cancer","name":"Early gastric cancer","route":"/cancers/early-gastric-cancer/"},{"id":"gastric","kind":"cancer","name":"Gastric & gastro-oesophageal junction cancer","route":"/cancers/gastric/"}],"institution":[{"id":"ncc-korea","kind":"institution","name":"National Cancer Center Korea","route":"/institutions/ncc-korea/"}],"person":[{"id":"hyung-ho-kim","kind":"person","name":"Hyung-Ho Kim","route":"/people/hyung-ho-kim/"}]}}