Laparoscopic colorectal resection for cancer: effects of conversion on long-term oncologic outcomes

The effects of conversion to open surgery during laparoscopic resection for colorectal cancer on long-term oncologic outcomes still are unclear. All 450 laparoscopic colorectal resections for cancer performed at a single center between 1994 and 2008 and included in a prospectively maintained database were considered. Patients who required conversion to open surgery (CONV) were matched 1:2 with laparoscopically completed cases (LAP) and 1:5 with open surgery cases (OPEN) for age, American Society of Anesthesiologists (ASA) score, year of surgery, tumor location, and tumor stage. Fisher's exact, chi-square, and Wilcoxon tests were used as appropriate. Kaplan-Meier curves were compared to analyze survival. In this study, 31 CONV cases were independently compared with 62 LAP and 155 OPEN cases. Compared with the LAP and OPEN patients, the CONV patients were characterized by a numerically higher rate of preoperative comorbidity (61.3% vs LAP, 51.6; P = 0.4 and OPEN, 48.4%; P = 0.2), male gender (77.4% vs LAP, 59.7%; P = 0.09 and OPEN, 58.1%; P = 0.05), and a significantly higher mean body mass index (29.6 vs LAP, 26.8; P = 0.012 and OPEN, 28.8; P = 0.3). The pathologic tumor stage, location, and chemotherapy and radiotherapy rates were comparable among the groups. After a median follow-up period of 4.1, 4.2, and 4.6 years, the 5-year disease-free survival rate was significantly lower for the CONV patients (40.2%) than for the LAP (70.7%, P = 0.01) or the OPEN (63.3%, P = 0.04) patients. However, the 5-year cancer-specific survival rates were similar among the CONV (94.4%), LAP (86.1%, P = 0.36), and OPEN (84.9%, P = 0.14) patients. Conversion to open surgery does not affect oncologic outcomes, although CONV patients have increased comorbidity rates affecting long-term mortality.