Abstract
BACKGROUND: The JCOG0404 randomized controlled trial conducted to compare laparoscopic surgery (LAP) with open surgery (OP) for stage II/III colon cancer showed better short-term outcomes and equal long-term outcomes of LAP versus OP. Technical instrumentation of surgery and anticancer agents given during the registration period might have affected the outcomes. AIM: To evaluate outcomes according to the registration periods. METHODS: The overall registration period was divided into three periods (first: 2004-2005, second: 2006-2007 and third: 2008-2009). Short-term and long-term outcomes were compared between registration periods. RESULTS: In total, 1057 patients were registered. Numbers of patients undergoing each approach for each of the three periods (1st/2nd/3rd) were 528 for OP (106/244/178) and 529 for LAP (106/246/177). Operation time (minutes) did not change between the periods for OP (160/156/161) or LAP (205/211/219). Blood loss (mL) gradually decreased in the latter two periods: (119/80/75) for OP and (35/28/25) for LAP. Incidence of complications (%) decreased in the latter periods for OP (27.6/20.3/21.3), whereas that for LAP remained consistently low (14.3/14.8/13.6). There was no particular trend in 5-year overall survival and recurrence-free survival depending on the period regardless of treatment. D3 dissection rates were 95% or more for all periods in both groups. CONCLUSIONS: Operation time and survival rates did not change over time, whereas blood loss in OP improved in the latter periods. Quality control applied in this trial might have been effective in producing such safe endpoints. (ClinicalTrials.gov, number NCT00147134, UMIN Clinical Trials Registry, number C000000105.).